nasa scientific and technical aerospace reports phần 1 pdf

2004; 3 pp.; In English; Original contains color illustrations Report No.s: AD-A432841; No Copyright; Avail: Defense Technical Information Center DTIC The aerodynamic performance of a wi

Trang 1

Issue 11 Volume 43

June 3, 2005

Trang 2

38 Quality Assurance and Reliability 132

39 Structural Mechanics 136

Geosciences 42 Geosciences (General) 138

43 Earth Resources and Remote Sensing 139

44 Energy Production and Conversion 141

45 Environment Pollution 144

46 Geophysics 151

47 Meteorology and Climatology 168

Life Sciences 51 Life Sciences (General) 173

52 Aerospace Medicine 216

53 Behavioral Sciences 217

54 Man/System Technology and Life Support 217

Mathematical and Computer Sciences 59 Mathematical and Computer Sciences (General) 221

60 Computer Operations and Hardware 223

61 Computer Programming and Software 224

62 Computer Systems 236

63 Cybernetics, Artificial Intelligence and Robotics 239

64 Numerical Analysis 244

65 Statistics and Probability 258

66 Systems Analysis and Operations Research 261

67 Theoretical Mathematics 264

Physics 70 Physics (General) 264

71 Acoustics 283

72 Atomic and Molecular Physics 287

73 Nuclear Physics 288

74 Optics 288

75 Plasma Physics 290

76 Solid-State Physics 291

77 Physics of Elementary Particles and Fields 302

Social and Information Sciences 80 Social and Information Sciences (General) 304

81 Administration and Management 305

82 Documentation and Information Science 309

83 Economics and Cost Analysis 318

Trang 3

Space Sciences

88 Space Sciences (General) 319

89 Astronomy 319

90 Astrophysics 322

91 Lunar and Planetary Science and Exploration 325

92 Solar Physics 413

General 99 General 414

Indexes

Two indexes are available You may use the find command under the tools menu while viewing the PDF file for direct match searching on any text string You may also select either of the two indexes provided for linking to the

corresponding document citation from NASA Thesaurus terms and personal author names.

Subject Term Index

Personal Author Index

Trang 4

02 AERODYNAMICS

Includes aerodynamics of flight vehicles, test bodies, airframe components and combinations, wings, and control surfaces Also includes

aerodynamics of rotors, stators, fans, and other elements of turbomachinery For related information see also 34 Fluid Mechanics and Thermodynamics.

20050173293 Tsentralni Aerogidrodinamicheskii Inst., Zhukovsky, Russia

Enhancement of Efficiency of Operation of High-Speed Aircraft Engine Elements by Means of Separation Flow Controlling

Guryleva, N V.; Ivankin, M A.; Kolesnikov, O M.; Lavrukhin, G N.; Merekin, D V.; Oct 2003; 3 pp.; In EnglishReport No.(s): AD-A432570; No Copyright; Avail: Defense Technical Information Center (DTIC)

Results of investigations of the mechanism of appearance and destruction of separation zones in supersonic gas flows arepresented Methods for controlling separation phenomena were developed to increase the operation efficiency of ductscombustors inlets and outlets of high-speed aircrafts The main trends of investigations were: 1) Study of deceleration flows

in ducts of various shapes with pseudoshock; 2) Development of non-traditional manners of spatial implementation ofcombustion in supersonic flows; 3) Computational analysis of optimum methods of energy supply in internal flows withseparation zones; 4) Control of separation phenomena for increasing efficiency of power plant outlets The following majorresults were obtained: For 1st trend: Features of the structure of the non-steady separation in the ducts with deceleration ofthe supersonic flow in the pseudoshock were determined Methods for controlling the pseudoshock were developed.Conditions for forming separation zones under interference of various shear layers (vortex jet) generated ahead of the entranceand in ducts with the pseudoshock were studied For 2nd trend: For the first time in the world practice the gasdynamicstabilizers of combustion were developed Their principle of operation was based on artificial generation of free-hangingseparation zones in the supersonic flow Successful experimental try-out of some schemes of gasdynamic stabilizers wascarried out at the TsAGI’s hypersonic test rig T-131 at M=2.5 - 2.6 They permitted to obtain self-ignition and stablecombustion of hydrogen:

DTIC

Aircraft Engines; Augmentation

20050173296 Moscow State Univ., Russia

Burning of the Supersonic Propane-Air Mixture in the Aerodynamic Channel With the Stagnant Zone

Shibkov, V M.; Chernikov, V A.; Ershov, A P.; Karachev, A A.; Konstantinovskij, R S.; Voskanyan, A V.; Zlobin, V V.;Oct 2003; 11 pp.; In English

Report No.(s): AD-A432573; No Copyright; Avail: Defense Technical Information Center (DTIC)

In the report the pulsed-periodical discharges created on an external surface of a flat plate being flown around ofsupersonic airflow and under condition of a stagnant zone located on a wide wall of the aerodynamic channel of rectangularsection were investigated It was show that the surface pulsed-periodical discharge results to ignition beforehand mixedsupersonic propane-air fuel in the aerodynamic channel In experimental conditions the combustion front speed reaches value

of v(sub c)=40-45 m/s that well coordinates to the data which was got at investigation of burning into the fire-resistant channel.The kinetical model is working out for finding-out of influence of different channels on ignition of combustible mixtures insupersonic flow The preliminary calculations demonstrate that at low initial gas temperature the induction time of H2-O2mixture decreases on some orders of magnitude at taking into account of dissociation active radicals and charged particles.DTIC

Aerodynamics; Combustion; Supersonic Flow

SCIENTIFIC AND TECHNICAL

AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration

VOLUME 43, JUNE 3, 2005

Trang 5

20050173423 Army Aviation and Missile Command, Redstone Arsenal, AL USA

Oblique Wing Aerodynamics

McDaniel, Melissa A.; Wilks, Brett L.; Dec 2004; 3 pp.; In English; Original contains color illustrations

The aerodynamic performance of a wing at an oblique deployment orientation has been found through wind tunnel testing

to affect both the lateral and longitudinal stability of a cruise missile While conventional analysis tools are insufficient forcalculating the aerodynamics of an oblique wing, a suitable method has been determined for use with the USAF MissileDATCOM code Comparisons made between wind tunnel results and Missile DATCOM calculations show that MissileDATCOM can produce a reasonable approximation of the aerodynamics of a wing at oblique deployment angles

DTIC

Aerodynamics; Oblique Wings

20050173428 Army Research Lab., Hampton, VA USA

Multibody Dynamics Simulation And Experimental Investigation of a Model-Scale Tiltrotor

Singleton, Jeffrey D.; Shen, Jinwei; Piatak, David J.; Dec 2004; 3 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432851; No Copyright; Avail: Defense Technical Information Center (DTIC)

The objective of this investigation is to develop a multibody analytical simulation model to predict the dynamic response,aeroelastic stability, and blade loading of a soft-inplane tiltrotor wind-tunnel model and correlate that with experimental data

A Joint Vertical Aircraft Task Force is currently developing requirements to meet Army and Navy needs for a heavy lifttransport rotorcraft that is expected to include, at a minimum, a 20-ton payload lift capability Development of soft-inplanetiltrotor technology is beneficial for providing viable lightweight hub design options for this future application Experimentaltesting, either in flight testing or with a wind tunnel test article, is becoming prohibitively expensive Advanced simulation andmodeling of these complex tiltrotor hub configurations using multibody dynamics codes may prove to be an alternative to suchexpensive experimental verifications in the future The use of multibody dynamics codes to predict and reduce the risk ofencountering aeromechanical instabilities and adverse loading situations for a soft-inplane tiltrotor hub design is detailed inthis investigation Comprehensive rotorcraft-based multibody analyses enable simulation and modeling of the rotor system to

a high level of detail such that complex mechanics and nonlinear e ects associated with control system geometry and jointfree-play may be considered The influence of these and other nonlinear e ects on the aeromechanical behavior of the tiltrotormodel is examined A parametric study of the design parameters which influence the aeromechanics of the soft-inplane rotorsystem is also included in this investigation

DTIC

Dynamic Response; Helicopters; Scale Models; Simulation; Tilt Rotor Aircraft

20050173484 Academy of Sciences (USSR), Moscow, USSR

Numerical Research of Capabilities of Flat Thermochemical Reactor as Element of a Hypersonic Flight Vehicle Heat Protection

Vasilyev, V K.; Korabelnikov, A V.; Fedotov, A V.; Oct 2003; 12 pp.; In English

Thermal protection of heat-stressed surfaces of a hypersonic flight vehicle (HFV) flying in dense layers of atmospherewith hypersonic velocities (M greater than or equal 7) is now one of the most actual problems 1,2 In HFV developed underthe ‘Ajax’ concept it is supposed that in the most heat- stressed parts of a skin and engine the chemical catalytic reactors will

be placed in which the high endothermic processes of decomposition of initial hydrocarbon fuel with the help of steam andcarbon dioxide reforming of methane and its liquid homologues have to be implemented 3 Such organization of the process

of thermochemical conversion of hydrocarbons onboard a flight vehicle (FV) will enable 4: - to increase a portion of usefulusage of a FV power resource at the expense of a chemical recuperation of heat losses connected as with aerodynamic heating

of a skin under the hypersonic flight conditions and power plant operation; - to increase cooling capability of fuel by means

of physical-chemical transformations (heating vaporization endothermic reactions) of initial components; - to provide anactive thermal protection (ATP) of heat-stressed parts of construction using not only heat removal by means of convection andradiation but also its absorption in a catalytic reaction run directly on the protected surface; - to influence positively on theconditions of a FV airflow-around at the expense of a skin construction cooling; - to obtain in reaction a synthesis gas (mixture

of H2 and CO) which will be directed to the combustion chamber for improvement of a fuel combustion characteristics.Thermochemical reactors (TCR) of various kinds used as elements of a HFV thermal protection as usual should decide twoproblems:

DTIC

Hypersonic Vehicles; Thermal Protection; Thermochemistry; Thermodynamics

Trang 6

03 AIR TRANSPORTATION AND SAFETY

Includes passenger and cargo air transport operations; airport ground operations; flight safety and hazards; and aircraft accidents.

Systems and hardware specific to ground operations of aircraft and to airport construction are covered in 09 Research and Support Facilities (Air) Air traffic control is covered in 04 Aircraft Communications and Navigation For related information see also 16 Space Transportation and Safety and 85 Technology Utilization and Surface Transportation.

20050173263 Space and Naval Warfare Systems Center, San Diego, CA USA

Transitioning Unmanned Ground Vehicle Research Technologies

Pacis, E B.; Everett, H R.; Farrington, N.; Kogut, G.; Sights, B.; Kramer, T.; Thompson, M.; Bruemmer, D.; Few, D.; Jan.2005; 12 pp.; In English; Original contains color illustrations

The Technology Transfer project employs a spiral development process to enhance the functionality and autonomy ofmobile systems in the Joint Robotics Program (JRP) Robotic Systems Pool (RSP) The approach is to harvest prior andon-going developments that address the technology needs identified by emergent in-theatre requirements and users of the RSP.The component technologies are evaluated on a transition platform to identify the best features of the different approacheswhich are then integrated and optimized to work in harmony in a complete solution The result is an enabling mechanism thatcontinuously capitalizes on state-of-the-art results from the research environment to create a standardized solution that can beeasily transitioned to ongoing development programs This paper focuses on particular research areas, specifically collisionavoidance, simultaneous localization and mapping (SLAM), and target-following and describes the results of their combinedintegration and optimization over the past 12 months

DTIC

Unmanned Ground Vehicles

20050173347 Massachusetts Inst of Tech., Lexington, MA USA

Information Theoretic Comparison of MIMO Wireless Communication Receivers in the Presence of Interference

Bliss, Daniel W.; Forsythe, Keith W.; Dec 2004; 30 pp.; In English; Original contains color illustrations

Multiple-input multiple-output (MI MO) wireless communication provides a number of advantages over traditionalsingle-input single-output (SISO) approaches including increased data rates for a given total transmit power and improvedrobustness to interference Many of these advantages depend strongly upon the details of the receiver implementation Forpractical communication systems a competition between communication performance and computational complexity exists

To reduce computation complexity suboptimal receivers are commonly employed In this paper the details of a variety ofreceivers are incorporated into the effects of the channel so that information-theoretic performance bounds can be exploited

to evaluate receiver approaches The performance of these receivers is investigated for a range of environments Two classes

of environments are considered: first channel complexity characterized by the shape of the narrowband channel-matrixsingular-value distribution and second external interference Receiver approaches include minimum-mean-squared errorminimum interference and multichannel multiuser detection (MCMUD) given various assumed limitations on channel andinterference estimation Receiver performance implications are also demonstrated using experimental data

DTIC

Information Theory; MIMO (Control Systems); Receivers; Wireless Communication

20050173377 Telcordia Technologies, Inc., Red Bank, NJ USA

Iterative Detection for Multi-User MIMO Systems

Liberti, Joseph; Martin, Carol C.; Mar 2004; 25 pp.; In English; Original contains color illustrations

Multi-input multi-output (MIMO) systems can serve as the building blocks for spectrally efficient mobile multi-usertactical wireless systems; however, care must be taken to translate high per-link spectral efficiency into high networkthroughput Mobile tactical networks generally have several features that complicate achievement of high multi-user MIMOspectral efficiency, including non-centralized, infrastructure-free operation and operation when all nodes are mobile, as well

as requirements to minimize probability of interception and susceptibility to jamming The paper presents results from bothsimulations and an extensive over-the-air measurement campaign, which illustrate the key features needed for spectrallyefficient multi-user MIMO systems High MIMO network throughput can be achieved by combining efficient MAC (takinginto account MIMO signal processing resources) and transmitter stream control, as well as high performance MIMO signal

Trang 7

processing and waveforms that minimize per-link signal-to-interference-and-noise ratio (SINR) requirements leading toeffective spectral reuse Iterative detection schemes provide such high spectral efficiency at low SINRs, achieving performancethat approaches the Shannon bound, and provide scalable complexity These methods are also well suited to operation inmulti-user environments, supporting both interference- mitigation and joint detection approaches The paper provides analysisand experimental results for waveforms and receiver signal processing for Space-Time Bit Interleaved Coded Modulationusing multi- carrier waveforms Results and parameter trades are presented for variations of this approach using List SphereDetection and Soft-Symbol Cancellation as well as structures based on convolutional codes and turbo codes.

DTIC

MIMO (Control Systems); Pulse Rate; Scalers

04 AIRCRAFT COMMUNICATIONS AND NAVIGATION

Includes all modes of communication with and between aircraft; air navigation systems (satellite and ground based); and air traffic

control For related information see also 06 Avionics and Aircraft Instrumentation, 17 Space Communications, Spacecraft Communications, Command and Tracking, and 32 Communications and Radar.

20050173231 University of West Florida, Pensacola, FL USA

Naval Automation and Information Management Technology

Pratt, Jerry; Neuhaus, Peter; Bradshaw, Jeffrey; Suri, Niranjan; Allen, James; Galescu, Lucian; Jan 2003; 16 pp.; In English;Original contains color illustrations

Contract(s)/Grant(s): N00014-03-1-0780

Military uses of unmanned systems are growing The use of unmanned systems, particularly UAVs, in the campaign inAfghanistan and in Iraqi Freedom operations demonstrated beyond any doubt the effectiveness and viability of unmannedsystems in !SR as well as weapons delivery missions As a result, in future military scenarios, large numbers of unmannedground, air, underwater, and surface vehicles will work together, coordinated by an ever smaller number of human operators

In order to be operationally efficient, effective and useful, these robots must have competent physical and sensing abilities,must be able to perform complex tasks semi-autonomously, must be able to coordinate with each other, and must ultimately

be observable and controllable in a useful and intuitive fashion by human operators Under the Naval Automation andInformation Management Technology Program (NAlMT), The Institute for Human and Machine Cognition (IHMC) of theUniversity of West Florida has conducted advanced research on unmanned systems in the areas of (1) unmanned underwatervehicle mobility, (2) human-agent teamwork and agile computing and (3) mixed initiative human control Progress made inFYO3 in each of these three areas is described below

DTIC

Information Management; Management Systems; Military Technology; Remotely Piloted Vehicles

05 AIRCRAFT DESIGN, TESTING AND PERFORMANCE

Includes all stages of design of aircraft and aircraft structures and systems Also includes aircraft testing, performance, and evaluation,

and aircraft and flight simulation technology For related information see also 18 Spacecraft Design, Testing and Performance; and 39 Structural Mechanics For land transportation vehicles see 85 Technology Utilization and Surface Transportation.

20050169564 North Carolina State Univ., Raleigh, NC, USA

Distributed Actuation and Sensing on an Uninhabited Aerial Vehicle

Barnwell, William Garrard; UAV Flight Control Using Distributed Actuation and Sensing; 2003; 120 pp.; In EnglishContract(s)/Grant(s): NAG1-01069; No Copyright; Avail: CASI;A06, Hardcopy

An array of effectors and sensors has been designed, tested and implemented on a Blended Wing Body Uninhabited AerialVehicle (UAV) The UAV is modified to serve as a flying, controls research, testbed This effector/sensor array provides forthe dynamic vehicle testing of controller designs and the study of decentralized control techniques Each wing of the UAV isequipped with 12 distributed effectors that comprise a segmented array of independently actuated, contoured control surfaces

A single pressure sensor is installed near the base of each effector to provide a measure of deflections of the effectors TheUAV wings were tested in the North Carolina State University Subsonic Wind Tunnel and the pressure distribution that resultfrom the deflections of the effectors are characterized The results of the experiments are used to develop a simple, but

Trang 8

accurate, prediction method, such that for any arrangement of the effector array the corresponding pressure distribution can

be determined Numerical analysis using the panel code CMARC verifies this prediction method

Author

Subsonic Wind Tunnels; Blended-Wing-Body Configurations; Pilotless Aircraft; Numerical Analysis; Control Systems Design

20050170033 NASA Lewis Research Center, Cleveland, OH, USA, McDonnell-Douglas Helicopter Co., USA, LucasWestern, Inc., USA, Illinois Univ., Chicago, IL, USA

Face Gear Technology for Aerospace Power Transmission Progresses

[2005]; 2 pp.; In English; No Copyright; Avail: CASI;A01, Hardcopy

The use of face gears in an advanced rotorcraft transmission design was first proposed by the McDonnell DouglasHelicopter Company during their contracted effort with the U.S Army under the Advanced Rotorcraft Transmission (ART)program Face gears would be used to turn the corner between the horizontal gas turbine engine and the vertical output rotorshaft a function currently done by spiral bevel gears This novel gearing arrangement would substantially lower the drivesystem weight partly because a face gear mesh would be used to split the input power between two output gears However,the use of face gears and their ability to operate successfully at the speeds and loads required for an aerospace environmentwas unknown Therefore a proof-of-concept phase with an existing test stand at the NASA Lewis Research Center waspursued Hardware was designed that could be tested in Lewis’ Spiral Bevel Gear Test Rig The initial testing indicated thatthe face gear mesh was a feasible design that could be used at high speeds and load Surface pitting fatigue was the typicalfailure mode, and that could lead to tooth fracture An interim project was conducted to see if slight modifications to the geartooth geometry or an alternative heat treating process could overcome the surface fatigue problems From the initial andinterim tests, it was apparent that for the surface fatigue problems to be overcome the manufacturing process used for thiscomponent would have to be developed to the level used for spiral bevel gears The current state of the art for face gearmanufacturing required using less than optimal gear materials and manufacturing techniques because the surface of the toothform does not receive final finishing after heat treatment as it does for spiral bevel gears This resulted in less than desirablesurface hardness and manufacturing tolerances An Advanced Research and Projects Agency (ARPA) TechnologyReinvestment Project has been funded to investigate the effects of manufacturing process improvements on the operatingcharacteristics of face gears The program is being conducted with McDonnell Douglas Helicopter Co., Lucas Western Inc.,the University of Illinois at Chicago, and a NASA/U.S Army team The goal of the project is develop the grinding process,experimentally verify the improvement in face gear fatigue life, and conduct a full-scale helicopter transmission test Thetheory and methodology to grind face gears has been completed, and manufacture of the test hardware is ongoing.Experimental verification on test hardware is scheduled to begin in fiscal 1996

Author

Gear Teeth; Rotary Wing Aircraft; Technology Utilization; Transmissions (Machine Elements); Aerospace Systems; Power Transmission

20050170431 General Electric Co., USA

First Test of Fan Active Noise Control (ANC) Completed

With the advent of ultrahigh-bypass engines, the space available for passive acoustic treatment is becoming more limited,whereas noise regulations are becoming more stringent Active noise control (ANC) holds promise as a solution to thisproblem It uses secondary (added) noise sources to reduce or eliminate the offending noise radiation The first active noisecontrol test on the low-speed fan test bed was a General Electric Company system designed to control either the exhaust orinlet fan tone This system consists of a ‘ring source,’ an induct array of error microphones, and a control computer Fan tonenoise propagates in a duct in the form of spinning waves These waves are detected by the microphone array, and the computeridentifies their spinning structure The computer then controls the ‘ring source’ to generate waves that have the same spinningstructure and amplitude, but 180 out of phase with the fan noise This computer generated tone cancels the fan tone before

it radiates from the duct and is heard in the far field The ‘ring source’ used in these tests is a cylindrical array of 16 flat-plateacoustic radiators that are driven by thin piezoceramic sheets bonded to their back surfaces The resulting source can producespinning waves up to mode 7 at levels high enough to cancel the fan tone The control software is flexible enough to work

on spinning mode orders from -6 to 6 In this test, the fan was configured to produce a tone of order 6 The complete modal(spinning and radial) structure of the tones was measured with two builtin sets of rotating microphone rakes These rakesprovide a measurement of the system performance independent from the control system error microphones In addition, thefar-field noise was measured with a semicircular array of 28 microphones This test represents the first in a series of tests that

Trang 9

demonstrate different active noise control concepts, each on a progressively more complicated modal structure The tests are

in preparation for a demonstration on a flight-type engine

Author

Active Control; Aerodynamic Noise; Fan Blades; Aeroacoustics; Turbofan Engines

20050170640 NASA Dryden Flight Research Center, Edwards, CA, USA

Doing Systems Engineering Without Thinking About It at NASA Dryden Flight Research Center

Bohn-Meyer, Marta; Kilp, Stephen; Chun, Peggy; Mizukami, Masashi; [2004]; 16 pp.; In English; IEEE AerospaceConference, 5-12 Mar 2005, Big Sky, MT, USA; Original contains color illustrations

Report No.(s): IEEEAC Paper 1194; No Copyright; Avail: CASI;A03, Hardcopy

When asked about his processes in designing a new airplane, Burt Rutan responded: there is always a performancerequirement So I start with the basic physics of an airplane that can get those requirements, and that pretty much sizes anairplane Then I look at the functionality And then I try a lot of different configurations to meet that, and then justify one

at a time, throwing them out Typically I’ll have several different configurations But I like to experiment, certainly I like

to see if there are other ways to provide the utility This kind of thinking engineering as a total systems engineering approach

is what is being instilled in all engineers at the NASA Dryden Flight Research Center

Author

Systems Engineering; NASA Programs; Research and Development; Flight Tests

20050171017 NASA Lewis Research Center, Cleveland, OH, USA, Department of the Army, USA

High-Temperature Magnetic Bearings for Gas Turbine Engines

Research and Technology 1995; March 1996; 2 pp.; In English; No Copyright; Avail: CASI;A01, Hardcopy

Magnetic bearings are the subject of a new NASA Lewis Research Center and U.S Army thrust with significant industryparticipation, and coordination with other Government agencies The NASA/Army emphasis is on high-temperatureapplications for future gas turbine engines Magnetic bearings could increase the reliability and reduce the weight of theseengines by eliminating the lubrication system They could also increase the DN (diameter of the bearing times rpm) limit onengine speed and allow active vibration cancellation systems to be used resulting in a more efficient, ‘more electric’ engine.Finally, the Integrated High-Performance Turbine Engine Technology (IHPTET) Program, a joint Department of Defense/industry program, identified a need for a hightemperature (as high as 1200 F) magnetic bearing that could be demonstrated

in a phase III engine This magnetic bearing is similar to an electric motor It has a laminated rotor and stator made of cobaltsteel Wound around the stator are a series of electrical wire coils that form a series of electric magnets around thecircumference The magnets exert a force on the rotor A probe senses the position of the rotor, and a feedback controller keeps

it in the center of the cavity The engine rotor, bearings, and case form a flexible structure that contains a large number ofmodes The bearing feedback controller, which could cause some of these modes to become unstable, could be adapted tovarying flight conditions to minimize seal clearances and monitor the health of the system Cobalt steel has a curie pointgreater than 1700 F, and copper wire has a melting point beyond that Therefore, practical limitations associated with themaximum magnetic field strength in the cobalt steel and the stress in the rotating components limit the temperature to about

1200 F The objective of this effort is to determine the limits in temperature and speed of a magnetic bearing operating in anengine Our approach is to use our in-house experience in magnets, mechanical components, high-temperature materials, andsurface lubrication to build and test a magnetic bearing in both a rig and an engine Testing will be done at Lewis or throughcooperative programs in industrial facilities

Derived from text

Gas Turbine Engines; Magnetic Bearings; High Temperature; Engine Design

20050172103 NASA Lewis Research Center, Cleveland, OH, USA, MacNeal-Schwendler Corp., USA

MSC/NASTRAN DMAP Alter Used for Closed-Form Static Analysis With Inertia Relief and Displacement-Dependent Loads

Research and Technology 1995; March 1996; 1 pp.; In English; No Copyright; Avail: Other Sources; Abstract OnlySolving for the displacements of free-free coupled systems acted upon by static loads is a common task in the aerospaceindustry Often, these problems are solved by static analysis with inertia relief This technique allows for a free-free staticanalysis by balancing the applied loads with the inertia loads generated by the applied loads For some engineeringapplications, the displacements of the free-free coupled system induce additional static loads Hence, the applied loads areequal to the original loads plus the displacement-dependent loads A launch vehicle being acted upon by an aerodynamic

Trang 10

loading can have such applied loads The final displacements of such systems are commonly determined with iterative solutiontechniques Unfortunately, these techniques can be time consuming and labor intensive Because the coupled system equationsfor free-free systems with displacement-dependent loads can be written in closed form, it is advantageous to solve for thedisplacements in this manner Implementing closed-form equations in static analysis with inertia relief is analogous toimplementing transfer functions in dynamic analysis An MSC/NASTRAN (MacNeal-Schwendler Corporation/NASAStructural Analysis) DMAP (Direct Matrix Abstraction Program) Alter was used to include displacement-dependent loads instatic analysis with inertia relief It efficiently solved a common aerospace problem that typically has been solved with aniterative technique.

Author

Displacement; Inertia; Nastran; Static Loads; NASA Programs

20050172129 NASA Dryden Flight Research Center, Edwards, CA, USA

Deflection-Based Structural Loads Estimation From the Active Aeroelastic Wing F/A-18 Aircraft

Lizotte, Andrew M.; Lokos, William A.; May 2005; 27 pp.; In English; 46th AIAA/ASME/ASCE/AHS/ASC Structures,Structural Dynamics and Materials Conference, 18-21 Apr 2005, Austin, TX, USA

Contract(s)/Grant(s): WU 723-56-00-SE-PR

Report No.(s): NASA/TM-2005-212871; H-2598; No Copyright; Avail: CASI;A03, Hardcopy

Traditional techniques in structural load measurement entail the correlation of a known load with strain-gage output fromthe individual components of a structure or machine The use of strain gages has proved successful and is considered thestandard approach for load measurement However, remotely measuring aerodynamic loads using deflection measurementsystems to determine aeroelastic deformation as a substitute to strain gages may yield lower testing costs while improvingaircraft performance through reduced instrumentation weight This technique was examined using a reliable strain andstructural deformation measurement system The objective of this study was to explore the utility of a deflection-based loadestimation, using the active aeroelastic wing F/A-18 aircraft Calibration data from ground tests performed on the aircraft wereused to derive left wing-root and wing-fold bending-moment and torque load equations based on strain gages, however, forthis study, point deflections were used to derive deflection-based load equations Comparisons between the strain-gage anddeflection-based methods are presented Flight data from the phase-1 active aeroelastic wing flight program were used tovalidate the deflection-based load estimation method Flight validation revealed a strong bending-moment correlation andslightly weaker torque correlation Development of current techniques, and future studies are discussed

Author

Aeroelasticity; Deflection; Wings; F-18 Aircraft; Aerodynamic Loads

20050173136 Department of Defense, Arlington, VA USA

Summary of Reports Issued and Participation on Management Advisory Teams and Special Audit/Evaluation Efforts

Mar 2004; 23 pp.; In English; Original contains color illustrations

This document is a summary of reports issued and participation on Management Advisory Teams and SpecialAudit/Evaluation efforts

DTIC

Acquisition; Finance; Management Planning

20050173137 Naval Postgraduate School, Monterey, CA USA

How Will the Indian Military’s Upgrade and Modernization of Its ISR, Precision Strike, and Missile Defense Affect the Stability in South Asia?

Dewan, Jay P.; Mar 2005; 89 pp.; In English; Original contains color illustrations

India has made a concerted effort to upgrade its ISR, precision strike, and missile defense capabilities as it competes withChina and Pakistan for regional power The Phalcon Airborne Warning and Control System, Su-30MKI fighter-bomberaircraft, and S-300PMU surface-to-air missile system are some examples of the new capabilities India is acquiring I arguethat if India continues its military modernization, Pakistan will become more insecure The increase in the conventionalmilitary capabilities gap will likely upset the existing balance of power in South Asia, leading to a regional arms race, loweringthe nuclear threshold, and increasing instability in the region The strategic stability/ tactical instability paradox that existsbetween two nuclear countries may lead them to engage in ‘small’ wars India’s increasing military capabilities may encourage

Trang 11

it to conduct a preventive strike against Pakistan In such a climate, a regional arms race eventually may lead Pakistan toestablish a ‘hair-trigger’ nuclear posture India’s effort to achieve a significantly superior conventional military force overPakistan paradoxically may reduce Indian security by causing greater instability, and possibly lead to nuclear war Regionalstability is enhanced to the extent that there is a rough conventional military balance between India and Pakistan.

DTIC

Asia; Bomber Aircraft; Fighter Aircraft; Military Technology; Missile Defense; Stability; Warfare

20050173269 Army Natick Soldier Center, Natick, MA USA

The Pathfinder Raven Small Unmanned Aerial Vehicle

Mawn, Andrew; Tokumaru, Phillip; Dec 2004; 8 pp.; In English; Original contains color illustrations

This paper provides an overview of the development of the Pathfinder Raven Small Unmanned Air Vehicle (SUAV) bythe U.S Army Natick Soldier Center and AeroVironment, Inc The concept for this SUAV system was initially explored duringthe Military Operations in Urban Terrain (MOUT) Advanced Concept Technology Demonstration (ACTD) and brought tofruition during the Pathfinder ACTD The spiral development process, the associated operational requirements and guidingprinciples used to quantify vehicle performance, physical characteristics, and methods of operation, are taken from theconceptual design stage to the current production aircraft The Pathfinder Raven aircraft has undergone numerous designrefinements and improvements in its evolution from concept to production The current production Pathfinder Raven SUAVmeets or exceeds the initial design objectives that could be boiled down to ‘do what a Pointer UAV does at half the size, cost,and weight.’ The production Pathfinder Raven SUAV is currently being used by U.S Army and USA Special OperationsCommand (USSOCOM) forces in combat operations worldwide in the global war on terrorism

DTIC

Drone Vehicles; Pilotless Aircraft

20050173289 Georgia Inst of Tech., Arlington, VA USA

Fire Resistant Closed Cell Foams for Aircraft Shelters Technical Review

Vitali, Juan; Beckham, Haskell; Mar 2004; 48 pp.; In English

DTIC

Fire Prevention; Fires; Foams; Shelters

20050173304 Department of Defense, Arlington, VA USA

Acquisition: Acquisition of the EA-6B Improved Capability III Program

Aug 2004; 55 pp.; In English

Report No.(s): AD-A432585; IG/DOD-D-2004-113; No Copyright; Avail: Defense Technical Information Center (DTIC)Who Should Read This Report and Why? Civil service and military managers involved in the management, support, andoversight of the EA-6B Improved Capability (ICAP) III Program should read this report because it discusses acquisition issuesthat must be addressed before the EA-6B ICAP III Program progresses further through the acquisition process The Servicesuse the airborne electronic attack capability to suppress and degrade an opposing force’s air defense and communicationsystems with airborne electronic jamming before offensive airborne strikes The Navy’s EA-6B Prowler (EA-6B) is the onlyDoD platform that provides the Services with an airborne electronic attack capability and must be able to suppress and degradecurrent and future threats through 2015 The EA-6B ICAP III Program will provide the EA-6B aircraft with upgradedselective-reactive jamming and threat emitter geo-location capabilities In June 2003, the Assistant Secretary of the Navy(Research, Development, and Acquisition) approved the program for low-rate initial production The Program Manager for theEA-6B (the Program Manager) subsequently awarded the prime contractor, Northrop Grumman Integrated Systems, Bethpage,New York, a firm-fixedprice modification to the development contract for low-rate initial production of 10 ICAP III systemkits for $102 million The Navy plans to acquire 35 ICAP III system kits for installation on 35 EA-6B aircraft As of June 2004,the ICAP III Program costs consisted of an estimated $335 million in research, development, test and evaluation funds, $458

Trang 12

million in procurement funds, and $109 million in operations and support funds for a total program cost of $902 million.DTIC

Costs; Electronic Aircraft; Jamming; Telecommunication

Enhancement of the Daytime Goes-Based Aircraft Icing Potential Algorithm Using MODIS

Alexander, Jeremy B.; Mar 2005; 106 pp.; In English; Original contains color illustrations

In this thesis, a fuzzy logic algorithm is developed for the detection of potential aircraft icing conditions using theModerate-Resolution Imaging Spectroradiometer (MODIS) The fuzzy MODIS algorithm is developed in a manner similar tothe cloud mask currently used to process MODIS imagery The MODIS icing potential detection algorithm uses thresholdsfor 8 channels in a series of 12 tests to determine the probability of icing conditions being present within a cloud The MODISalgorithm results were compared to results of the GOES icing potential detection algorithm run on MODIS imagery for 4cases When compared to positive and icing pilot reports for the cases, the MODIS algorithm identified regions where icingwas encountered more effectively than the GOES algorithm Furthermore, the use of fuzzy thresholds on MODIS rather thanthe hard thresholds of the GOES algorithm allowed for less restrictive coverage of potential icing conditions, making theMODIS algorithm more reasonable in assessing all cloud regions for icing potential The results found here are preliminary,

as further statistical analysis with a larger validation dataset would be more effective Algorithm details are provided in theappendix for reference

DTIC

Aircraft Icing; Algorithms; Augmentation; Daytime; Fuzzy Systems; Ice Formation; Imaging Spectrometers; MODIS (Radiometry); Spectroradiometers

20050173327 Stavatti Military Aerospace, Saint Paul, MN USA

Cold Plasma Cavity Active Stealth Technology

Beskar, Christopher R.; Nov 2004; 11 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432633; SD-272278-WP; No Copyright; Avail: Defense Technical Information Center (DTIC)STAVATTI Military Aerospace has undertaken the development of a proprietary mechanism by which to reduce the RCS

of aerospace and surface vehicles Identified as ‘Cold Plasma Cavity Active Stealth Technology’ by STAVATTI, thismechanism is appropriate for aircraft/vehicles requiring all-aspect RCS reduction, as well as those destined for export to awide variety of allied air forces/militaries as it enables a ‘stealth aircraft/vehicle’ to be reconfigured to a non-stealthconfiguration through the removal of critical Line Removable Units (LRUs) responsible for the generation and management

of the cold plasma responsible for electromagnetic attenuation

DTIC

Cavities; Cold Plasmas; Fighter Aircraft; Radar Cross Sections; Stealth Technology

20050173379 Army Research Lab., Hampton, VA USA

Active-Twist Rotor Control Applications for UAVs

Wilbur, Matthew L.; Wilkie, W K.; Dec 2004; 9 pp.; In English; Original contains color illustrations

The current state-of-the-art in active-twist rotor control is discussed using representative examples from analytical andexperimental studies, and the application to rotary-wing UAVs is considered Topics include vibration and noise reduction,rotor performance improvement, active blade tracking, stability augmentation, and rotor blade de-icing A review of the currentstatus of piezoelectric fiber composite actuator technology, the class of piezoelectric actuators implemented in active-twistrotor systems, is included

DTIC

Active Control; Noise Reduction; Rotary Wings; Rotors; Stability; Vibration

Determining the Fine Structure of the Entrainment Zone in Cloud-Topped Boundary Layers

Horner, Michael S.; Mar 2005; 93 pp.; In English; Original contains color illustrations

The objective of this thesis is to obtain a better understanding of cloud-top entrainment through an in-depth analysis of

Trang 13

entrainment-zone structure In situ aircraft measurements taken during the Atlantic Stratocumulus Transition Experiment(ASTEX) were used for this purpose Using data collected from multiple cloud-top penetrations, the presence of an interfaciallayer in-between the top of the cloud mixed-layer and the base of the free atmosphere is identified and consequently defined

as the entrainment zone The depth of the entrainment zone is on the order of tens of meters, where turbulence and sometimescloud droplets are detectable Inhomogeneous mixing was found to occur within the entrainment zone Parcels ofinversion-layer air and boundary-layer air are identified within the entrainment zone Analyses suggest that turbulenceintensity and cloud amount in the entrainment zone vary depending on the distribution of entrainment mixing fraction.Furthermore, continuous mixing in the entrainment zone appears to dissipate the upper-cloud layer However, continuousdissipation of the upper-cloud layer has not been observed Further study is needed to determine the interaction betweenboundary-layer dynamics

DTIC

Atmospheres; Boundary Layers; Cloud Cover; Cloud Physics; Electronic Aircraft; Entrainment; Fine Structure; Marine Meteorology

20050173437 Iowa State Univ of Science and Technology, Ames, IA USA

VR Aided Control of Unmanned Vehicles

Walter, Bryan E.; Knutzon, Jared S.; Sannier, Adrian V.; Oliver, James H.; Dec 2004; 9 pp.; In English; Original containscolor illustrations

A new design for an immersive ground control station is presented that allows operators to monitor and control one ormore semiautonomous unmanned vehicles This new ground station utilizes a virtual reality visualization of the operationalspace and the graphical representation of multiple real time information streams to create a comprehensive immersiveenvironment designed to significantly enhance an operator’s situational awareness and effectiveness The environmentsimultaneously informs the operator about the position and condition of the vehicles under his or her control while providing

an organizing context for the available information relevant to the engagement This design is applicable to a range of vehiclesincluding unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs)

DTIC

Command and Control; Virtual Reality

20050173460 Army Research Lab., Adelphi, MD USA

Acoustic Detection from Aerial Balloon Platform

Reiff, C.; Pham, T.; Scanlon, M.; Noble, J.; Van Landuyt, A.; Petek, J.; Ratches, J.; Dec 2004; 9 pp.; In English; Originalcontains color illustrations

The US Army Research Laboratory (ARL) and US Army Night Vision and Electronic Sensors Directorate (NVESD) areleading the research and development in autonomous sensing and sensor networks for the Networked Sensors for the FutureForce (NSfFF) and Future Combat System (FCS) With the emphasis being shifted to lighter and more mobile forces, ARLand NVESD have been collaborating and exploring various mobile platforms such as robotic vehicles and aerial platformssuch as unmanned aerial vehicles (UAVs) and balloons Our most immediate collaboration focuses on the use of acousticsensors on small balloons and/or aerostats at several elevations and on the ground with the primary goals of: (i) investigatethe acoustic sensing and detection ranges; (ii) acoustically cue IR imagers and/or video cameras; and (iii) explore thenetworking of elevated sensors and ground sensors for NSfFF In this paper, we only focus on the first goal, the acousticdetection portion of the collaborative effort

DTIC

Balloon-Borne Instruments; Balloons; Drone Vehicles; Flying Platforms; Sound Detecting and Ranging

20050173464 University of Central Florida, Orlando, FL USA

Collaborative UAV Exploration of Hostile Environments

Luotsinen, Linus J.; Gonzalez, Avelino J.; Boeloeni, Ladislau; Dec 2004; 7 pp.; In English; Original contains colorillustrations

Unmanned Aerial Vehicles are frequently used for the exploration of a hostile environment UAVs can be lost orsignificantly damaged during the exploration process Although employing multiple UAVs can increase the chance of success,

Trang 14

their efficiency depends on the collaboration strategies used We present a cooperative exploration strategy for UAVscontrolled by autonomous agents The agents are sharing information, coordinate their short-term goals and path choices,while each agent uses state of the art algorithms for its individual path planning and obstacle avoidance The overall goals are

to minimize the exploration time, avoid damage by sharing information about threats, and be robust to the failures ofindividual UAVs Extensive simulation results prove the validity of the approach and provide ways to determine the optimalnumber of UAVs for different exploration tasks

DTIC

Algorithms; Autonomous Navigation; Combat; Data Systems; Drone Vehicles; Pilotless Aircraft; Surveillance

20050173475 Army Aeromedical Research Lab., Fort Rucker, AL USA

Flexible Display Technologies Do They Have a Role in the Cockpit?

Rash, Clarence E.; Harris, Eric S.; McGilberry, William H.; Mar 2005; 12 pp.; In English

Report No.(s): AD-A432947; USAARL-2005-07; No Copyright; Avail: CASI;A03, Hardcopy

The 21st century promises a new ‘holy grail’ of display technologies With the long-promised arrival of the plasma displayallowing ‘hang-on-the-wall?’ television, the display community has moved on to the promise of fully conformable displays,known as flexible displays This touted new class of displays is not actually unique in itself but is actually an assortment ofnovel subclasses of existing display technologies These technologies include liquid crystal, light emitting diode (LED) andelectrophoresis Flexible displays based on these technologies are advertised as thinner (almost paper thin), lighter weight,stronger (extremely rugged and durable), cheaper, super efficient and conformable, as compared to current rigid, mounteddisplays Currently, organic LED (OLED) and electrophoretic displays are examples of flexible displays that have entered thecommercial market The aviation community may find these displays highly desirable for cockpit applications However, caremust taken to ensure that good human factors engineering principles are adhered to in such applications

DTIC

Cockpits; Display Devices

20050173535 BMH Associates, Inc., Norfolk, VA USA

Air Virtual at Sea (VAST) Platform Stimulation Analysis

Jan 2005; 22 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): N00014-04-M-0074

Information included in this report is outlined as follows: 1) VAST/LVC integration Concept; 2) VAST/LVC IntegrationArchitecture; 3) Demonstration Concept; 4) Schedule and Cost; and 5) Engineering Management Topics

DTIC

Avionics; Flying Platforms; Seas; Stimulation; Training Devices; Virtual Reality; Weapon Systems

07 AIRCRAFT PROPULSION AND POWER

Includes primary propulsion systems and related systems and components, e.g., gas turbine engines, compressors, and fuel systems;

and onboard auxiliary power plants for aircraft For related information see also 20 Spacecraft Propulsion and Power; 28 Propellants and Fuels; and 44 Energy Production and Conversion.

20050169930 NASA Lewis Research Center, Cleveland, OH, USA

Effect of Tabs on a Rectangular Nozzle Studied

In a continuing research program, jets from nozzles of different geometries are being investigated with the aim ofincreasing mixing and spreading in those flows Flow fields from nozzles with elliptic, rectangular, and other more complexcross-sectional shapes are being studied in comparison to circular nozzles over a wide Mach number range As noted byprevious researchers, noncircular jets usually spread faster than circular jets Another technique being investigated to increasejet spreading even further for a given nozzle is the use of ‘tabs’ to generate vortices A typical tab is a triangular-shapedprotrusion placed at the nozzle exit, with the base of the triangle touching the nozzle wall and the apex leaning downstream

at 45 to the stream direction This geometry was determined by a parametric study to produce the optimum effect for a givenarea blockage The tabs can increase jet spreading significantly The underlying mechanism traces to a pair of counter-rotating

Trang 15

streamwise vortices originating from each tab These vortex pairs persist in the flow; and with the appropriate number andstrength, they can increase spreading.

Author

Nozzle Geometry; Nozzle Design; Supersonic Nozzles; Rectangles; Nozzle Flow; Jet Flow

08 AIRCRAFT STABILITY AND CONTROL

Includes flight dynamics, aircraft handling qualities, piloting, flight controls, and autopilots For related information see also 05 Aircraft Design, Testing and Performance and 06 Avionics and Aircraft Instrumentation.

20050173306 Massachusetts Inst of Tech., Lexington, MA USA

Small Polarimetric Adaptive Array for Airborne GPS Jammer Suppression

Blejer, Dennis; Ngai, Eugene C.; Phuong, Tri T.; Mar 2004; 6 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432593; No Copyright; Avail: Defense Technical Information Center (DTIC)

MIT Lincoln Laboratory has designed, built, tested, and analyzed a small polarimetric adaptive array for airborne GPSjammer suppression The array has 7 channels and is configured as a square array The array consists of a right-hand circularlypolarized (RHCP) reference element and 3 dual-linearly polarized elements The rationale for the design was to create a7-channel array with 1 RHCP reference element that had acceptable levels of mutual coupling and fit within a 7 inch by 7 inchfootprint The approach taken was to convert 3 of the 4 elements of a 4-element RHCP array to 3 dual-linearly polarizedelements This modification actually simplifies the construction of the array by eliminating 3 hybrid couplers Thismodification results in up to 6 degrees of freedom for the polarimetric array The concept of using dual-polarized elements

in an adaptive array was considered by R.T Compton, Jr and presented in his text, Adaptive Antennas He showed that usingdual-polarized elements allows a polarization null to be directed towards an interfering source while receiving a desired signalthat is co-linear with the interferer and the receiver, provided the desired signal and the interfering signal have somewhatdifferent polarizations He also showed that using an array with different element patterns can have better performance than

an array of isotropic elements under certain conditions This paper will concentrate on the measured performance of the smallpolarimetric adaptive array The complex element patterns of the array were measured on a small ground plane in an MITLincoln Laboratory indoor chamber, and a few azimuthal patterns were measured with the array on a Falcon 20 aircraft in thePatuxent River Chamber

DTIC

Adaptation; Antenna Arrays; Global Positioning System; Jammers; Polarimetry

09 RESEARCH AND SUPPORT FACILITIES (AIR)

Includes airports, runways, hangars, and aircraft repair and overhaul facilities; wind tunnels, water tunnels, and shock tubes; flight

simulators; and aircraft engine test stands Also includes airport ground equipment and systems For airport ground operations see 03 Air Transportation and Safety For astronautical facilities see 14 Ground Support Systems and Facilities (Space).

Laser Sheet Flow Visualization Developed for Lewis’ Icing Research Tunnel

A new flow-visualization technique has been developed for use in the NASA Lewis Research Center’s Icing ResearchTunnel (IRT) This technique uses a sheet of light shining across the wind tunnel to illuminate a mist of water droplets in theair and display any organized flow patterns Since the IRT already has the special water spray system required for aircraft icingexperiments, no special visualization seeding material is required The system has been used to visualize the changes in tipand leading edge vortices caused by ice accretion Because the IRT’s icing spray is used as part of the visualization technique,changes in the flow patterns about a wing can be observed and measured during the ice accretion process

Author

Flow Visualization; Laser Applications; Flow Measurement; Aircraft Icing

Trang 16

12 ASTRONAUTICS (GENERAL)

Includes general research topics related to space flight and manned and unmanned space vehicles, platforms or objects launched into,

or assembled in, outer space; and related components and equipment Also includes manufacturing and maintenance of such vehicles

or platforms For specific topics in astronautics see categories 13 through 20 For extraterrestrial exploration see 91 Lunar and Planetary Science and Exploration.

20050173384 RAND Corp., Santa Monica, CA USA

USA Air and Space Power in the 21st Century: Strategic Appraisal

Khalilzad, Zalmay; Shapiro, Jeremy; Jan 2002; 495 pp.; In English

Contract(s)/Grant(s): F49642-01-C-0003

Report No.(s): AD-A432766; RAND/MR-1314; No Copyright; Avail: Defense Technical Information Center (DTIC)Aerospace power has become the archetypal expression of the U.S ability to project force in the modern world.Throughout the world, U.S aerospace power and thus, the U.S Air Force (USAF) plays a critical, and often primary, role insecuring U.S interests, in promoting American values, and in protecting human rights While the USAF has had significantsuccess in employing aerospace power in the recent past, emerging trends in international relations, in technology, and in ourown domestic society will create a wide variety of new challenges and new opportunities for U.S aerospace power Meetingthese challenges and exploiting these opportunities will require careful planning, wise investments, and thoughtful training,

as well as difficult cultural adaptations within the USAF This book identifies many of these challenges and opportunities in

a wide variety of issue areas and assesses the degree to which the USAF is prepared to meet them While the work was carriedout under the auspices of the Strategy and Doctrine program of RAND’s Project AIR FORCE, which is sponsored by the U.S.Air Force, this volume draws on the expertise of researchers from across RAND in a variety of related disciplines The primaryaudience of this work consists of Air Force leaders and planners, but it should be of interest to others concerned about nationalsecurity issues

DTIC

Aerospace Systems; Education; Military Operations; United States

20050173391 National War Coll., Washington, DC USA

Mahan’s Elements of Sea Power Applied to the Development of Space Power

France, Martin E.; Jan 2000; 15 pp.; In English

As of today, no definitive work on space power theory, comparable to the writings of Clausewitz, Mahan, Mitchell (andothers in their respective fields), is recognized by military theorists Though most preliminary space power writing in the USAhas centered on space as a logical extension of air power theory (if for no other apparent reason than the organizationallocation of most space forces within the U.S Air Force), such treatment is akin to early Army characterizations of aircraft as

a tool of the artillery or signal corps, restricted to supporting ground operations While space is certainly a unique operationalsetting that has yet to be fully exploited, it shares many characteristics with the sea as an arena for commerce, transport,observation and conflict In fact, because of the distances involved, the importance of constantly safeguarding the free flow

of global commerce (e.g information) in both peace and war, and the more or less permanent basing of key civil and militaryassets in orbit, space power, missions and responsibilities have many analogs to the sea Therefore, one would do well toconsider first the earlier work of sea power theorists, specifically A.T Mahan, when attempting to develop a theory of spacepower and to develop strategies for space control

DTIC

Seas; Space Missions

20050173472 Science Applications International Corp., San Diego, CA USA

Spacecraft Potential Control

Davis, Victoria A.; Gardner, Barbara M.; Jungeward, G A.; Mandell, Myron J.; Jul 2004; 70 pp.; In English; Originalcontains color illustrations

Trang 17

Effects (SEE) Program at NASA/MSFC The end result of the program is a user friendly computer code that computesspacecraft charging in dense and tenuous plasma environments The primary focus of the SEE Program’s contribution wasfunding development of the graphical user interface and user documentation, as well as a related program to measure relevantmaterial properties.

DTIC

Algorithms; Computerized Simulation; Earth Orbits; Spacecraft Charging; Spacecraft Control

20050173489 Bari Univ., Italy

A Model For Ammonia Solar Thermal Thruster

Capitelli, Mario; Colonna, G.; Dec 2004; 16 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432967; EOARD-SPC-03-3072; No Copyright; Avail: Defense Technical Information Center (DTIC)This reports results from a contract tasking University of BARI as follows: The kinetics of nozzle expansion flow is atopic of large interest- due to its linking with technological applications Usually one can treat the problem by using twoapproaches The first one is to use complicated 2D fluid dynamics codes with poor kinetics, second one is to use ID nozzlecodes emphasizing the role of chemical kinetics in affecting the whole fluid-chemical problem The second approach has beenused by our group to characterize simple gases such as H2, N2, 02 and their mixtures The peculiarity of our approach is todescribe each vibrational level of the molecule as a new species thus avoiding the concept of vibrational temperature Thisapproach could be in principle extended to polyatomic molecules even though in this case the state tot state kinetics becomes

a very difficult problem These concepts will be developed in the present proposal which deals with the characterization ofthe kinetics of NH3 through nozzles of different geometries Our proposal consists of different steps including: 1) development

of a realistic kinetics for ammonia decomposition, 2) development of a realistic macroscopic model for vibrationaldeactivation of polyatomic molecules, 3) evaluation of the dependence of rates on vibrational temperature 4) insertion ofpoints 1-3 in the nozzle equations and 5) examination of results for different nozzle geometries

DTIC

Ammonia; Propulsion System Configurations; Propulsion System Performance; Solar Energy

13 ASTRODYNAMICS

Includes powered and free flight trajectories; orbital and launching dynamics.

Aerosol Scattering Phase Function Retrieval From Polar Orbiting Satellites

Wunder, Daniel P.; Mar 2005; 97 pp.; In English; Original contains color illustrations

The retrieval of an aerosol scattering phase function using a multi-satellite technique is proposed A total of 33 phasefunctions were derived from 18 smoke cases and 15 dust cases Each case was interrogated using four to nine satellite passesover the aerosol in a two to four hour time frame The radiance values for the Red and Near-Infrared (NIR) channels werecombined with backscattering angles to determine the shape of the scattering phase function The radiance values were inputinto the Naval Postgraduate School (NPS) aerosol model to determine optical depths and sample phase functions Acomparison was made between the actual phase functions retrieved and the NPS model phase functions It was found that thephase functions for the smoke cases more closely matched the model phase functions than in the dust cases Some conclusionscould be drawn about the actual aerosol size and density distribution based on how well it matched the model phase function.Further analysis is necessary to define the exact size and number of the aerosol particles Fully understanding the aerosolcomposition is crucial in determining its effects on military sensors and impacts to operations

DTIC

Aerosols; Artificial Satellites; Near Infrared Radiation; Polar Orbits; Scattering; Scattering Functions; Trajectories

Trang 18

14 GROUND SUPPORT SYSTEMS AND FACILITIES (SPACE)

Includes launch complexes, research and production facilities; ground support equipment, e.g., mobile transporters; and test chambers

and simulators Also includes extraterrestrial bases and supporting equipment For related information see also 09 Research and Support Facilities (Air).

INTEX Ka-Band Experiment Ground Terminal

The INTEX (interference experiment) Ka-Band Experiment Ground Terminal was developed by NASA Lewis ResearchCenter’s Advanced Space Communications Laboratory to enable space communications experiments that use the AdvancedCommunications Technology Satellite (ACTS) INTEX is used for a wide range of ACTS technology validation andinvestigation experiments as well as application demonstrations It also supports experiments for other organizations withinand outside of NASA

Author

ACTS; Extremely High Frequencies; Space Communication; Ground Stations

Mach 6 Integrated Systems Tests of Lewis’ Hypersonic Tunnel Facility

A series of 15 integrated systems tests were conducted at the NASA Lewis Research Center’s Hypersonic Tunnel Facility(HTF) with test conditions simulating flight up to Mach 6 Facility stagnation conditions up to 3050 R and 1050 psia wereobtained with typical test times of 20 to 45 sec

Author

Hypersonic Wind Tunnels; Systems Integration; Wind Tunnel Tests

20050171038 NASA Lewis Research Center, Cleveland, OH, USA, Jet Propulsion Lab., California Inst of Tech., Pasadena,

CA, USA

Lewis Mars Pathfinder Microrover Experiments

The NASA Lewis Research Center has a prime role in the Mars Pathfinder mission, the first in the series ofDiscovery-class missions, sponsored by NASA Headquarter’s Office of Space Science Mars Pathfinder is an engineeringproof-of-concept mission intended to demonstrate the successful deployment of scientific instruments, including a small rover,

on a planetary body and to gain engineering design information for follow-on systems The mission was launched in December

1996 and will land on Mars on July 4, 1997

Author

Mars Pathfinder; Mars Roving Vehicles; Onboard Equipment; Experimentation

15 LAUNCH VEHICLES AND LAUNCH OPERATIONS

Includes all classes of launch vehicles, launch/space vehicle systems, and boosters; and launch operations For related information see

also 18 Spacecraft Design, Testing and Performance; and 20 Spacecraft Propulsion and Power.

20050173154 Aerospace Corp., El Segundo, CA USA

Life Modeling for Nickel-Hydrogen Batteries in Geosynchronous Satellite Operation

Zimmerman, A H.; Ang, V J.; Mar 2005; 26 pp.; In English; Original contains color illustrations

to predict how properly designed and operated nickel-hydrogen battery lifetimes should depend on the operating environments

Trang 19

and charge control methods typically used in GEO operation Lifetime is found to be strongly dependent on DOD (particularly

at high operating DOD levels), amount of overcharge, trickle-charge rate, and operating temperature In addition, the modelfinds a strong coupling between these wear-controlling parameters The model suggests that with an optimized charge controlsystem and optimized operating conditions, properly designed nickel-hydrogen batteries are capable of reliably providing over

30 years of GEO operation at a DOD of 70-75% The results also indicate that careful optimization of charge control, operatingtemperature, and the maximum required DOD are needed to guarantee reliable operation beyond 10 years

DTIC

Artificial Satellites; Electric Batteries; Models; Nickel Hydrogen Batteries

Fuel Optimal Low Thrust Trajectories for an Asteroid Sample Return Mission

Rust, Jack W.; Mar 2005; 75 pp.; In English; Original contains color illustrations

This thesis explores how an Asteroid Sample Return Mission might make use of solar electric propulsion to send aspacecraft on a journey to the asteroid 1989ML and back It examines different trajectories that can be used to get an asteroidsample return or similar spacecraft to an interplanetary destination and back in the most fuel-efficient manner While currentplans call for keeping such a spacecraft on the asteroid performing science experiments for approximately 90 days, it isprudent to inquire how lengthening or shortening this time period may affect mission fuel requirements Using optimal controlmethods, various mission scenarios have been modeled and simulated The results suggest that the amount of time that thespacecraft may spend on the asteroid surface can be approximated as a linear function of the available fuel mass Furthermore,

It can be shown that as maximum available thrust is decreased, the radial component of the optimal thrust vector becomesmore pronounced

DTIC

Asteroid Missions; Electric Propulsion; Fuel Consumption; Low Thrust; Sample Return Missions; Trajectories

20050173372 Air Force Inst of Tech., Wright-Patterson AFB, OH USA

Engineering Tools for Variable Stiffness Vibration Suppression and Isolation

Winthrop, Michael F.; Dec 2004; 211 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432732; AFIT/DS/ENY/05-02; No Copyright; Avail: Defense Technical Information Center (DTIC)With the advent of smart materials, the concept of semi-active control or dynamic control of stiffness and/or damping forvibration control of structures has become practical and has seen limited use Semi-active control has advantages over activeand passive control methods, since it provides almost as much capability as active control while requiring much less power.Its main disadvantage is its inherent nonlinearity, greatly complicating engineering design The purpose of this research is toextend semi-active control vibration isolation tools and methods considering space launch and on-orbit systems

DTIC

Damping; Nonlinearity; Spacecraft Components; Stiffness; Vibration Isolators

20050173426 Rice Univ., Houston, TX USA

Robust Constrained Optimization Approach to Control Design for International Space Station Centrifuge Rotor Auto Balancing Control System

Postma, Barry D.; Apr 2005; 134 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432849; CI04-1040; No Copyright; Avail: Defense Technical Information Center (DTIC)

This thesis discusses application of a robust constrained optimization approach to control design to develop an AutoBalancing Controller (ABC) for a centrifuge rotor to be implemented on the International Space Station The design goal is

to minimize a performance objective of the system, while guaranteeing stability and proper performance for a range ofuncertain plants The performance objective is to minimize the translational response of the centrifuge rotor due to a fixedworst-case rotor imbalance The robustness constraints are posed with respect to parametric uncertainty in the plant Theproposed approach to control design allows for both of these objectives to be handled within the framework of constrainedoptimization The resulting controller achieves acceptable performance and robustness characteristics

DTIC

Approach Control; Balancing; Centrifuges; International Space Station; Optimization; Rotary Wings

Trang 20

20050173461 Air Force Inst of Tech., Wright-Patterson AFB, OH USA

Impact of a Military Reusable Launch Vehicle on Dominant Maneuver and Focused Logistics

Williams, Nanette M.; Jun 2000; 58 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432917; AFIT/GMO/ENS/00E-13; No Copyright; Avail: Defense Technical Information Center (DTIC)This study analyzes the role of a next-generation reusable launch vehicle (RLV) as a potential defense mobility platformfor the future RLV prototypes offer rapid transportation anywhere on the globe within one hour, with a significant costreduction from today’s $10,000 per pound to $1,000 per pound of cargo through space Unfortunately, extremely complex andtime-consuming infrastructure and ground handling requirements hinder the usefulness of the RLV in a military environment.Joint Vision 2020 (JV2020) outlines operational concepts that mold warfighting capabilities to achieve full spectrumdominance in the future Two of the operational concepts, dominant maneuver and focused logistics, shape mobilityrequirements and are used to evaluate the need for a military RLV This project seeks to answer the question: ‘Could thenext-generation RLV be a viable tool to support JV2020’s operational concepts of dominant maneuver and focused logistics?’Based on this analysis, current RLV prototypes do not meet the majority of criteria established by JV2020’s dominantmaneuver and focused logistics However, if a military RLV were designed and produced specifically for defensetransportation, it could potentially overcome the reliability and flexibility obstacles and become a key enabler toward fullspectrum dominance

DTIC

Launch Vehicles; Logistics; Military Technology; Reusable Launch Vehicles; Transportation

20050173466 University of Central Florida, Orlando, FL USA

A Scale MOUT Facility for Studying Human-Robot Interaction and Control

Jentsch, Florian; Evans, Arthur W., III; Feldman, Moshe; Hoeft, Raegan M.; Rehfeld, Sherri A.; Curtis, Michael; Dec 2004;

8 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): DAAD19-01-C-0065; N61339-04-C-0034

The Human Research and Engineering Directorate (HRED) of the US Army Research Laboratory (ARL) is involved in

a 5-year program to understand the implications of introducing new technology and procedures to enhance human roboticinteractions (HRI) for the Objective Force Warrior (OFW) and Future Combat Systems (FCS) An important component ofthe HRI research is the study of the collaborative requirements for human robotic teams The Team Performance Laboratory(TPL) at the University of Central Florida (UCF) has been contracted to conduct research whose purpose is to understand andenhance the interaction of multiple soldiers with multiple robotic systems that vary in size from small unmanned groundsystems (SUGVs), to medium sized unmanned aerial vehicles (UAVs) , to six-ton armored robot vehicles (ARVs)

DTIC

Military Vehicles; Robot Control; Robotics

16 SPACE TRANSPORTATION AND SAFETY

Includes passenger and cargo space transportation, e.g., shuttle operations; and space rescue techniques For related information see

also 03 Air Transportation and Safety; 15 Launch Vehicles and Launch Operations; and 18 Spacecraft Design, Testing and Performance For space suits see 54 Man/System Technology and Life Support.

20050169563 NASA Stennis Space Center, Stennis Space Center, MS, USA

SMARR (Safety and Mission Assurance Readiness Review)

Failla, David P.; April 20, 2005; 4 pp.; In English; SMARR, 20 Apr 2005, Stennis Space Center, MS, USA

Report No.(s): SPPT-8600-0001; No Copyright; Avail: CASI;A01, Hardcopy

This document from the Stennis Space Center Office of Safety and Mission Assurance rates flight preparation elementsfor Space Shuttle mission STS-114 All elements are rated with the status ‘Standard Open Work or Completed’, and marked

in green on the document, which contains a Certificate of Flight Readiness for STS-114

Author

Aerospace Safety; Flight Safety; Safety Factors; Space Shuttles; Space Transportation System Flights; Preflight Analysis

Trang 21

17 SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING

Includes space systems telemetry; space communications networks; astronavigation and guidance; and spacecraft radio blackout For

related information see also 04 Aircraft Communications and Navigation; and 32 Communications and Radar.

Low-Complexity, Digital Encoder/Modulator Developed for High-Data-Rate Satellite B-ISDN Applications

The Space Electronics Division at the NASA Lewis Research Center is developing advanced electronic technologies forthe space communications and remote sensing systems of tomorrow As part of the continuing effort to advance thestate-of-the-art in satellite communications and remote sensing systems, Lewis developed a low-cost, modular, programmable,and reconfigurable all-digital encoder-modulator (DEM) for medium- to high-data-rate radiofrequency communication links.The DEM is particularly well suited to high-data-rate downlinks to ground terminals or direct data downlinks from near-Earthscience platforms It can support data rates up to 250 megabits per second (Mbps) and several modulation schemes, includingthe traditional binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modes, as well as higher orderschemes such as 8 phase-shift keying (8PSK) and 16 quadrature amplitude modulation (16QAM) The DEM architecture alsocan precompensate for channel disturbances and alleviate amplitude degradations caused by nonlinear transpondercharacteristics

Author

Spacecraft Electronic Equipment; Coders; Satellite Communication

18 SPACECRAFT DESIGN, TESTING AND PERFORMANCE

Includes satellites; space platforms; space stations; spacecraft systems and components such as thermal and environmental controls;

and spacecraft control and stability characteristics For life support systems see 54 Man/System Technology and Life Support For related information see also 05 Aircraft Design, Testing and Performance; 39 Structural Mechanics; and 16 Space Transportation and Safety.

20050169874 NASA, Washington, DC, USA

Beyond the Baseline: Proceedings of the Space Station Evolution Symposium, Volume 2, Part 2, Space Station Freedom Advanced Development Program

May 1990; 344 pp.; In English; First Annual Space Station Evolution Symposium: Beyond the Baseline, 6-8 Feb 1990,League City, TX, USA

Contract(s)/Grant(s): UPN 488-00-00

Report No.(s): NASA-CP-10044-Vol-2-PT-2; S-606-Vol-2-Pt-2; No Copyright; Avail: CASI;A15, Hardcopy

This report contains the individual presentations delivered at the Space Station Evolution Symposium in League City,Texas on February 6, 7, 8, 1990 Personnel responsible for Advanced Systems Studies and Advanced Development within theSpace Station Freedom program reported on the results of their work to date Systems Studies presentations focused onidentifying the baseline design provisions (hooks and scars) necessary to enable evolution of the facility to support changingspace policy and anticipated user needs Also emphasized were evolution configuration and operations concepts includingon-orbit processing of space transfer vehicles Advanced Development task managers discussed transitioning advancedtechnologies to the baseline program, including those near-term technologies which will enhance the safety and productivity

of the crew and the reliability of station systems Special emphasis was placed on applying advanced automation technology

to ground and flight systems This publication consists of two volumes Volume 1 contains the results of the advanced systemstudies with the emphasis on reference evolution configurations, system design requirements and accommodations, andlong-range technology projections Volume 2 reports on advanced development tasks within the Transition DefinitionProgram Products of these tasks include: engineering fidelity demonstrations and evaluations on Station development testbedsand Shuttle-based flight experiments; detailed requirements and performance specifications which address advancedtechnology implementation issues; and mature applications and the tools required for the development, implementation, andsupport of advanced technology within the Space Station Freedom Program

Author (revised)

Space Station Freedom; Aerospace Systems; Spacecraft Design; Systems Engineering; Automation

Trang 22

20050173425 Army Aviation and Missile Command, Redstone Arsenal, AL USA

Non-Line-Of-Sight Launch System - A Lethal Combination

Haynes, Greg; Hyman, Elizabeth; Dec 2004; 3 pp.; In English; Original contains color illustrations

The Non-Line-of-Sight Launch System (NLOS-LS) will provide enabling lethality for the Army’s Future Combat System(FCS) The NLOS-LS, one of 19 FCS Core Systems, will consist of a family of missiles and a highly deployable,platform-independent Container Launch Unit (C/LU) with self-contained tactical fire control electronics and software forremote and unmanned operations

DTIC

Launching; Line of Sight; Missiles

19 SPACECRAFT INSTRUMENTATION AND ASTRIONICS

Includes the design, manufacture, or use of devices for the purpose of measuring, detecting, controlling, computing, recording, or

processing data related to the operation of space vehicles or platforms For related information see also 06 Avionics and Aircraft Instrumentation; for spaceborne instruments not integral to the vehicle itself see 35 Instrumentation and Photography; for spaceborne telescopes and other astronomical instruments see 89 Astronomy.

20050169831 Jet Propulsion Lab., California Inst of Tech., Pasadena, CA, USA

Monitoring Floods with NASA’s ST6 Autonomous Sciencecraft Experiment: Implications on Planetary Exploration

Ip, Felipe; Dohm, J M.; Baker, V R.; Castano, B.; Chien, S.; Cichy, B.; Davies, A G.; Doggett, T.; Greeley, R.; Sherwood,R.; Lunar and Planetary Science XXXVI, Part 9; [2005]; 2 pp.; In English; See also 20050169816; Original contains colorillustrations; Copyright; Avail: CASI;A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parentdocument

NASA’s New Millennium Program (NMP) Autonomous Sciencecraft Experiment (ASE) [1-3] has been successfullydemonstrated in Earth-orbit NASA has identified the development of an autonomously operating spacecraft as a necessity for

an expanded program of missions exploring the Solar System The versatile ASE spacecraft command and control, imageformation, and science processing software was uploaded to the Earth Observer 1 (EO-1) spacecraft in early 2004 and has beenundergoing onboard testing since May 2004 for the near real-time detection of surface modification related to transientgeological and hydrological processes such as volcanism [4], ice formation and retreat [5], and flooding [6] Space autonomytechnology developed as part of ASE creates the new capability to autonomously detect, assess, react to, and monitor dynamicevents such as flooding Part of the challenge has been the difficulty to observe flooding in real time at sufficient temporalresolutions; more importantly, it is the large spatial extent of most drainage networks coupled with the size of the data setsnecessary to be downlinked from satellites that make it difficult to monitor flooding from space Below is a description of thealgorithms (referred to as ASE Flood water Classifiers) used in tandem with the Hyperion spectrometer instrument on EO-1

to identify flooding and some of the test results

Derived from text

Space Exploration; Spacecraft Control; Aerospace Engineering; Floods; Image Processing; Real Time Operation

20 SPACECRAFT PROPULSION AND POWER

Includes main propulsion systems and components, e.g., rocket engines; and spacecraft auxiliary power sources For related

information see also 07 Aircraft Propulsion and Power, 28 Propellants and Fuels, 15 Launch Vehicles and Launch Operations, and 44 Energy Production and Conversion.

Advanced Power Regulator Developed for Spacecraft

The majority of new satellites generate electrical power using photovoltaic solar arrays and store energy in batteries foruse during eclipse periods Careful regulation of battery charging during insolation can greatly increase the expected lifetime

of the satellite The battery charge regulator is usually custom designed for each satellite and its specific mission Economiccompetition in the small satellite market requires battery charge regulators that are lightweight, efficient, inexpensive, andmodular enough to be used in a wide variety of satellites A new battery charge regulator topology has been developed at the

Trang 23

NASA Lewis Research Center to address these needs The new regulator topology uses industry-standard dc-dc converters and

a unique interconnection to provide size, weight, efficiency, fault tolerance, and modularity benefits over existing systems Atransformer-isolated buck converter is connected such that the high input line is connected in series with the output This

‘bypass connection’ biases the converter’s output onto the solar array voltage Because of this biasing, the converter onlyprocesses the fraction of power necessary to charge the battery above the solar array voltage Likewise, the same converterhookup can be used to regulate the battery output to the spacecraft power bus with similar fractional power processing Theadvantages of this scheme are: 1) Because only a fraction of the power is processed through the dc-dc converter, the single-stage conversion efficiency is 94 to 98 percent; 2) Costly, high-efficiency dc-dc converters are not necessary for highend-to-end system efficiency; 3) The system is highly fault tolerant because the bypass connection will still deliver power ifthe dc-dc converter fails; and 4) The converters can easily be connected in parallel, allowing higher power systems to be builtfrom a common building block This new technology will be spaceflight tested in the Photovoltaic Regulator Kit Experiment(PRKE) on TRW’s Small Spacecraft Technology Initiative (SSTI) satellite scheduled for launch in 1996 This experiment usescommercial dc-dc converters (28 to 15 Vdc) and additional control circuitry to regulate current to a battery load The 60-W,87- percent efficiency converters can control 180 W of power at an efficiency of 94 percent in the new configuration Thepower density of the Photovoltaic Regulator Kit Experiment is about 200 W/kg

Author

Power Effıciency; Regulators; Small Satellite Technology; Electric Power

High-Aspect-Ratio Cooling Channel Concept Tested in Lewis’ Rocket Engine Test Facility

1995; 2 pp.; In English; No Copyright; Avail: CASI;A01, Hardcopy

Rocket combustion chamber walls are exposed to the high-temperature environment caused by the combustion ofpropellants Even with the walls actively cooled by the fuel, the hot gases can deteriorate the walls severely and limit anypossibility for reusing the combustion chamber For many years, the NASA Lewis Research Center has performed subscaleinvestigations of potential improved cooling concepts to extend the life and reliability of the combustion chamber Resultsfrom previous subscale tests have shown that, by increasing the coolant channel height-to-width aspect ratio, the rocketcombustion chamber hot gas side wall temperature can be reduced by as much as 28 percent, without an increase in the coolantpressure drop Recently, a series of experiments were completed in Lewis’ Rocket Engine Test Facility (RETF) to validate thebenefits of high aspect ratio cooling channels with a high-pressure, contoured rocket combustion chamber

Author

Liquid Propellant Rocket Engines; Engine Tests; Engine Parts; Engine Coolants

Advanced Power Regulator Developed for Spacecraft

The majority of new satellites generate electrical power using photovoltaic solar arrays and store energy in batteries foruse during eclipse periods Careful regulation of battery charging during insolation can greatly increase the expected lifetime

of the satellite The battery charge regulator is usually custom designed for each satellite and its specific mission Economiccompetition in the small satellite market requires battery charge regulators that are lightweight, efficient, inexpensive, andmodular enough to be used in a wide variety of satellites A new battery charge regulator topology has been developed at theNASA Lewis Research Center to address these needs The new regulator topology uses industry-standard dc-dc converters and

a unique interconnection to provide size, weight, efficiency, fault tolerance, and modularity benefits over existing systems Atransformer-isolated buck converter is connected such that the high input line is connected in series with the output This

‘bypass connection’ biases the converter’s output onto the solar array voltage Because of this biasing, the converter onlyprocesses the fraction of power necessary to charge the battery above the solar array voltage Likewise, the same converterhookup can be used to regulate the battery output to the spacecraft power bus with similar fractional power processing.Author

Voltage Regulators; Electric Batteries; Battery Chargers; Spacecraft Power Supplies; Photovoltaic Cells

20050173427 Army Research Lab., Aberdeen Proving Ground, MD USA

Development of Advanced Rocket Engine Technology for Precision Guided Missiles

Nusca, Michael J.; Michaels, R S.; Dec 2004; 9 pp.; In English; Original contains color illustrations

Trang 24

The Army is developing hypergolic, liquid and gelled bipropellants for a small, selectable-thrust, liquid rocket engine(LRE) that can power tactical missiles for both current and future combat systems The use of gel propellants brings theadvantages of selectable thrust and the promise of small engine size but also introduces new challenges in combustion control.One of these challenges is the efficient mixing of gelled oxidizer and fuel to obtain maximum performance from the LREcombustor without increasing the size of the engine The Army’s impinging stream vortex engine, ISVE, offers an efficientalternative to increasing the combustion chamber volume of a LRE and has already generated excellent performance test data.Since the ISVE is a new concept, analytical models that relate engine performance to engine design parameters are justbeginning to emerge In order to fully exploit the performance that have been realized for the ISVE, it is desirable tounderstand the underlying flow physics of the engine This paper describes the Army s effort to use multidimensional,multiphase computational fluid dynamics, combined with high-performance computers to generate simulations of the ISVEthat reveal combustion patterns as well as predict chamber pressure and thrust levels for the engine The goal is to utilize thiscomputational tool to optimize the ISVE performance for a host of strategic Army missions.

DTIC

Liquid Propellant Rocket Engines; Missiles; Rocket Engines

23 CHEMISTRY AND MATERIALS (GENERAL)

Includes general research topics related to the composition, properties, structure, and use of chemical compounds and materials as they

relate to aircraft, launch vehicles, and spacecraft For specific topics in chemistry and materials see categories 25 through 29 For astrochemistry see category 90 Astrophysics.

20050169742 Missouri Univ., Rolla, MO, USA

Low Temperature Cathode Supported Electrolytes Report for April 1, 2001-September 30, 2001

Anderson, H U.; Huebner, W.; 2001; 156 pp.; In English

Report No.(s): DE2004-834069; No Copyright; Avail: Department of Energy Information Bridge

This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic ElectricalCharacterization and testing of Planar Single Cells In this portion of study we have focused on producing YSZ films on porousLSM substrates When using the polymer precursor there are a number of obstacles to overcome in order to form denseelectrolyte layers on porous substrates (cathode or anode) Probably the most difficult problems are: (1) Extreme penetration

of the polymer into the substrate must be prevented (2) Shrinkage cracking must be avoided (3) Film thickness in the 1 to5(micro)m range must be achieved We have demonstrated that cracking due to shrinkage involved during the elimination ofsolvents and organic matter and densification of the remaining oxide is not a problem as long as the resulting oxide film is

\h (approx) 0.15 (micro)m in thickness We have also shown that we can make thicker films by making multiple depositions

if the substrate is smooth (roughness (le) 0.1 (micro)m) and contains no surface pores \g 0.2 (micro)m

NTIS

Yttrium Oxides; Zirconium Oxides; Cathodes; Annealing

20050169792 California Univ., Lawrence Berkeley National Lab., Berkeley, CA, USA

Surface Engineering of Glazing Materials and Structures Using Plasma Processes

Anders, A.; Monteiro, O R.; 2004; 10 pp.; In English

A variety of coatings is commercially produced on a very large scale, including transparent conducting oxides andmulti-layer silver-based low-emissivity and solar control coatings A very brief review of materials and manufacturing process

is presented and illustrated by ultrathin silver films and chevron copper films Understanding the close relation betweenmanufacturing processes and bulk and surface properties of materials is crucial for film growth and self-assembly processes.NTIS

Metal Films; Plasmas (Physics); Surface Properties; Thin Films; Glazes

20050169847 California Univ., Lawrence Berkeley National Lab., Berkeley, CA, USA, Leipzig Univ., German DemocraticRepublic, National Renewable Energy Lab., Golden, CO, Argonne National Lab., IL

Distribution and Chemical State of Cu-rich Clusters in Silicon

Buonassisi, T.; Istratov, A A.; Weber, E R.; Marcus, M A.; Heuer, M.; Aug 2004; 12 pp.; In English

Report No.(s): DE2004-15009893; NREL/CP-520-36748; No Copyright; Avail: Department of Energy Information Bridge

Trang 25

The chemical state and distribution of Cu-rich clusters were determined in four different silicon-based materials withvarying contamination pathways and degrees of oxygen concentration, including as-grown multicrystalline silicon In all foursamples, Cu3Si was the only chemical state observed Cu3Si clusters were observed at structural defects within all fourmaterials; XBIC measurements revealed that the presence of Cu3Si corresponds to increased recombination activity Oxidized

Cu compounds are not likely to form in silicon The +1 eV edge shift in the -XAS absorption spectrum of Cu3Si relative to

Cu metal is believed to be an indication of a degree of covalent bonding between Cu atoms and their silicon neighbors.NTIS

Copper; Metal Clusters; Oxygen; Silicon

20050169853 National Renewable Energy Lab., Golden, CO

Commercial Status of the PV Industry in 2004-Identifying Important and Unimportant Factors

von Roedern, B.; Aug 2004; 12 pp.; In English

Report No.(s): DE2004-15009891; NREL/CP-520-36681; No Copyright; Avail: Department of Energy Information BridgeThis paper reviews the current status of the commercial PV Industry It assesses the current status of commerciallyavailable modules, most of which use silicon wafers or ribbons My analysis will show that the choice of Si wafers orsubstrates, once deemed to be the most important aspect, ended up making only negligible differences for commercialproducts, as long as cells are prepared by diffusion and screen printing I will also address the prospects and requirements forboth next generation thin-film modules and super-high (\g20%) efficient commercial crystalline Si cells It is shown thattraditional recombination loss analyses provide a poor tool for understanding limitations of cell and module performance,because those analytical schemes ignore dominating interactions between different loss mechanisms (e.g., of surface and bulkrecombination)

Report No.(s): PB2005-102997; No Copyright; Avail: CASI;A04, Hardcopy

Contents include the following: Three-dimensional microstructure simulation model of cement based materials;Ultrasonic underside inspection for fatigue cracks in the deck plate of a steel orthotropic bridge deck; and Measuring spatialcorrelation of soil properties

NTIS

Three Dimensional Models; Microstructure; Metal Fatigue

20050169882 Missouri Univ., Rolla, MO, USA

Low Temperature Cathode Supported Electrolytes

Anderson, H U.; 2004; 48 pp.; In English

This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic ElectricalCharacterization and Testing of Planar Single Cells During this time period substantial progress has been made in developinglow temperature deposition techniques to produce dense, nanocrystalline yttrium-stabilized zirconia films on both dense oxideand polymer substrates Progress has been made in the preparation and characterization of thin electrolytes and porous LSMsubstrates Both of these tasks are essentially on or ahead of schedule In our proposal, we suggested that the ZrO(sub 2)/Scsystem needed to be considered as a candidate as a thin electrolyte This was because microcrystalline ZrO(sub 2)/Sc has asignificantly higher ionic conductivity than YSZ, particularly at the lower temperatures As a result, some 0.5 micron thick film

of ZrO(sub 2)/16% Sc on an alumina substrate (grain size 20nm) was prepared and the electrical conductivity measured as

a function of temperature and oxygen activity

NTIS

Cathodes; Electrolytes; Thin Films

Trang 26

20050170626 Karpov (V Y.) Physical Chemistry Inst., Moscow, USSR

Diamond Nanograins in Carbon Soot: Does the Chemistry of Extracted Diamonds Depend on the Properties of Pristine Soot?

Koscheev, A P.; Zaripov, N V.; Ott, U.; Lunar and Planetary Science XXXVI, Part 11; [2005]; 2 pp.; In English; See also20050170551; Original contains color illustrations

Contract(s)/Grant(s): RFBR-03-05-64678; RFBR-02-05-04001; Copyright; Avail: CASI; A01, Hardcopy; Available fromCASI on CD-ROM only as part of the entire parent document

Main efforts in the study of presolar diamond nanograins have been directed towards the isotopic analysis of traceelements (primarily, noble gases) [1] trapped inside the grains and the results allow to draw conclusions regarding stellarnucleosynthesis [1,2] The surface chemistry of interstellar diamonds has been studied to much lesser extent, in spite of thefact that, due to the small size of diamond grains (2-4 nm) and their large surface to volume ratio, the surface species canrepresent a substantial part of grain material Information about surface chemistry of diamond grains is important for thefollowing reasons First, the possibility exists that at least some extraterrestrial surface features of nanodiamonds may havesurvived [3] If so, diamond grains with different history may reveal different surface chemistry Second, surface species ondiamond nanograins may be responsible for some of the IR absorption features observed in spectra of the interstellar medium[4,5] and it is necessary to know the relation between surface chemistry and optical properties of nanodiamonds

Derived from text

Carbon; Soot; Diamonds; Trace Elements; Rare Gases; Interstellar Chemistry; Chemical Reactions; Interstellar Matter

20050170928 Research Inst of National Defence, Linkoeping, Sweden

Defence Applications of Nanocomposite Materials

Savage, S J.; Dec 2004; 26 pp.; In English

Report No.(s): PB2005-103080; FOI-R-1456-SE; No Copyright; Avail: CASI;A03, Hardcopy

This report briefly describes and discusses relevant properties of polymer-based nanocomposite materials, and givesexamples of the actual and potential use of nanocomposite materials in defense applications

NTIS

Composite Materials; Nanocomposites

20050172062 Iowa State Univ of Science and Technology, Ames, IA, USA

Development of New Cryocooler Regenerator Materials Ductile Intermetallic Compounds

Gschneidner, K A.; Pecharsky, A O.; Pecharsky, V K.; 2004; 14 pp.; In English

The volumetric heat capacities of a number of binary and ternary Er- and Tm-based intermetallic compounds, whichexhibited substantial ductilities, were measured from (approx)3 to (approx)350 K They have the RM stoichiometry (where

R = Er or Tm, and M is a main group or transition metal) and crystallize in the CsCl-type structure The heat capacities ofthe Tm-based compounds are in general larger than the corresponding Er-based materials Many of them have heat capacitieswhich are significantly larger than those of the low temperature (\h15 K) prototype cryocooler regenerator materials HoCu(sub2), Er(sub 3)Ni and ErNi Utilization of the new materials as regenerators in the various cryocoolers should improve theperformance of these refrigeration units for cooling below 15 K

NTIS

Intermetallics; Transition Metals; Cryogenic Cooling

A Multi-Agent System for Tracking the Intent of Surface Contacts in Ports and Waterways

Tan, Kok S.; Mar 2005; 90 pp.; In English; Original contains color illustrations

Maritime security is especially critical for countries like Singapore, an island nation situated on the world’s busiestshipping routes, whose economic prosperity is highly dependent on international trade from her busy port, petrochemicalcomplexes and other high value units located along her coastline This thesis borrows the ideas and techniques suggested foridentifying air threats in the Air Defense Laboratory (ADL) and employ them to identify asymmetric maritime threats in portand waterways Each surface track is monitored by a compound multi-agent system that comprise of the several intent models,each containing a nested multi-agent system The attributes that define intent models of friendly, neutral, unknown andpotentially hostile surface contacts are obtained from movement and communication protocols defined by the Vessel Traffic

Trang 27

Information System (VTIS), maritime navigation rules and cues for surface warfare threat assessment The underlyingcognitive mechanism of the models is conceptual blending The study includes a simulation of a mock VTS for the port ofSingapore and surrounding waterways to test the ability of the models to compress data and information regarding multiplesimulated surface contacts into integration networks and then determine the surface contacts’ intent through the expansion ofthe integration networks.

DTIC

International Trade; Threat Evaluation; Waterways

20050173399 Geo-Centers, Inc., Aberdeen Proving Ground, MD USA

Feasibility of Formulating DECON GREEN with Airfraft Deicing Fluid: VX, GD, and HD Reactivity

Wagner, George W.; Procell, Lawrence R.; Kiple, Joseph B.; Taylor, Jeffrey S.; Yang, Yu-Chu; Jan 2005; 13 pp.; In English;Original contains color illustrations

Contract(s)/Grant(s): DAAM01-98-C-0008

Report No.(s): AD-A432798; ECBC-TR-381; No Copyright; Avail: Defense Technical Information Center (DTIC)

DECON GREEN is a reactive, universal decontaminant for VX, HD, and G agents composed of bicarbonate (bakingsoda), hydrogen peroxide, and alcohol The use of two currently fielded aircraft deicing fluids, containing ethylene glycoland/or propylene glycol and water, as substitutes for the alcohol constituent was assessed by examining the VX, GD, and HD)reactivity in formulations using these materials

DTIC

Decontamination; Deicing; Ethylene Compounds; Formulations; Glycols; Propylene; Reactivity

20050173453 Army Research Lab., Aberdeen Proving Ground, MD USA

An Ab Initio Study of Solid Nitromethane, HMX, RDX, and CL20: Successes and Failures of DFT

Byrd, Edward F.; Chabalowski, Cary F.; Scuseria, Gustavo E.; Dec 2004; 9 pp.; In English; Original contains colorillustrations

Using the PW91 and PBE density functional theories (DFT), we have studied four energetic molecular crystals:nitromethane, HMX, RDX, and CL20 with a wide range of basis sets Our goal is to assess the accuracy of DFT when applied

to organic molecular crystals (such as energetic materials) as scientists are beginning to include this methodology in energeticmaterials research without knowledge of the limitations of the method Intramolecular distances, simple angles, and band gapsare converged at plane wave cutoff energies of 430 to 495 eV Cell parameters were determined over a range of values from

280 eV to 700 or 800 eV, depending upon the system Lattice vectors, however, display large errors in the range of 0.2 to 1.0,and a very slow convergence on basis set size We hypothesize the error in the lattice vectors is due to a lack of van der Waalsforces in current DFT functionals This deficiency will have unforeseen consequences on all crystal calculations for organicmolecules, and therefore caution should be employed whenever interpreting results obtained from the current DFT functionalsavailable in solid state codes To properly describe the electronic structure of these types of crystals, these results suggest theneed for new methods involving DFT to be developed which include accurate dispersion forces

DTIC

Failure; Hmx; Nitramine Propellants; Nitromethane; RDX; Solid Phases

24 COMPOSITE MATERIALS

Includes physical, chemical, and mechanical properties of laminates and other composite materials.

20050169727 Manchester Metropolitan Univ., UK

Finite Element Modelling of an Optical Antenna using Piezoelectric Polymer Coated D-Fibre

Bhatti, A.; Al-Raweshidy, H S.; Murtaza, G.; IEEE Antennas and Propagation Society International Symposium, Volume 1;[1999], pp 674-677; In English; See also 20050169565; Copyright; Avail: Other Sources

Over the years, optical fibre sensors have been developed for many application areas One potentially interestingapplication for this type of sensor is in the detection of radio frequency electric fields By constructing such a sensor fromtotally dielectric materials, it may be used as an antenna for receiving radio frequency transmissions without distorting ordisturbing the field lines since there are no metallic components to reflect or transmit radio frequency energy This type ofantenna has the potential of wide bandwidth and high sensitivity In addition, it offers other advantages over conventional

Trang 28

antennae such as intrinsic safety in hazardous environments as well as geometrical flexibility which enables its use in smartstructure systems It has been shown that the optical phase shift of light propagating in a singlemode optical fibre coated with

a piezoelectric plastic jacket can be modulated by an applied voltage Piezoelectric polymers such as Polyvinylidene Fluoride(PVDF) have been shown to respond to frequencies approaching 20GHz Such an electric field sensing device consists of asinglemode (silica) optical fibre coated with a transversely poled jacket that is placed between parallel plate electrodes.Application of a voltage to create an electric field between the metal electrodes induces strains in the piezoelectric jacket due

to the converse piezoelectric effect The strains in the jacket are directly transmitted to the glass fibre The strain-inducedchanges in refractive index and length of the fibre produce a phase shift of the lightwave propagating in the fibre core whichprovides a measure of the applied electrical field An alternative to the conventional pVDF coated circular fibre as the sensingelement is a PVDF coated D-fibre Optical D-fibres have a D-shaped cross-section Main advantage of D-fibre, as shown, isthe closeness of the guiding region to the flat surface of the fibre, thus making it particularly attractive for sensing applications.Most of the work with conventional circular singlemode optical fibre electric field sensors employing piezoelectric polymercoatings has remained focused on theoretical and experimental characterisation of these devices which can be expensive andtime consuming However, an assessment of the response of the device can be made by using commercially available finiteelement analysis (FEA) software, with the obvious time and expense benefits Utilising the finite element method also allowsinitial test simulations to be performed to study the device structure in order to achieve an optimized design prior tofabrication Whilst mathematical modelling has proved a valuable tool for studying the response of electric field sensors based

on conventional circularly symmetric optical fibres, the complex geometrical structure of the D-fibre does not allow thedevelopment of a straight-forward analytical model FEA provides a suitable alternative in characterizing the response of theD-fibre sensor This work describes, for the first time, the novel approach of using FEA to simulate the response of a opticalD-fibre antenna A wide frequency response from 100Hz to 50MHz of the phase shift induced in a D-shaped optical fibrejacketed with a transversely polarized piezoelectric material is presented

Author

Fabrication; Finite Element Method; Mathematical Models; Optical Fibers; Piezoelectricity; Vinyl Polymers; Coatings

DMBZ Polyimides Provide an Alternative to PMR-15 for High-Temperature Applications

PMR-15, a high-temperature polyimide developed in the mid-1970’s at the NASA Lewis Research Center, offers thecombination of ease of processing, low cost, and good stability and performance at temperatures up to 288 C (500 F) Thismaterial is widely regarded as one of the leading high-temperature matrix resins for polymer-matrix-composite aircraft enginecomponents PMR-15 is widely used in both military and civilian aircraft engines The current worldwide market for PMR-15

is on the order of 50,000 lb, with a total sales of around $5 to $10 million However, PMR-15 is made from methylene dianiline(MDA), a known animal mutagen and a suspected human mutagen Recent concerns about the safety of workers involved inthe manufacture and repair of PMR-15 components have led to the implementation of costly protective measures to limitworker exposure and ensure workplace safety In some cases, because of safety and economic concerns, airlines haveeliminated PMR-15 components from engines in their fleets Current efforts at Lewis are focused on developing suitablereplacements for PMR-15 that do not contain mutagenic constituents and have processability, stability, and mechanicalproperties comparable to that of PMR-15 A recent development from these efforts is a new class of thermosetting polyimidesbased on 2,2’-dimethylbenzidine (DMBZ) Autoclave processing developed for PMR-15 composites was used to preparelow-void-content T650-35 carbon-fiber-reinforced laminates from DMBZ-15 polyimides The glass transition temperatures ofthese laminates were about 50 C higher than those of the T650- 35/PMR-15 composites (400 versus 348 C) In addition,DMBZ-15 polyimide composites aged for 1000 hr in air at 288 C (500 F) had weight losses close to those of comparablePMR-15 laminates (0.9 versus 0.7 percent) The elevated (288 C) and room temperature mechanical properties ofT650-35-reinforced DMBZ-15 polyimide and PMR-15 laminates were comparable Standard Ames tests are being conducted

on this diamine to assess its mutagenicity

Author

Diamines; Polyimides; Mechanical Properties; Benzene; Dimethyl Compounds; Refractory Materials; Composite Materials

Fully Associative, Nonisothermal, Potential-Based Unified Viscoplastic Model for Titanium-Based Matrices

A number of titanium matrix composite (TMC) systems are currently being investigated for high-temperature air frameand propulsion system applications As a result, numerous computational methodologies for predicting both deformation and

Tiêu đề	Quality Assurance and Reliability
Trường học	NASA Scientific and Technical Aerospace Reports
Chuyên ngành	Aerospace Science
Thể loại	Báo cáo khoa học
Năm xuất bản	2005
Thành phố	Washington

Định dạng
Số trang	56
Dung lượng	325,78 KB