introduction to simatic hmi

... only too well known There are so many scientific terms named after Newton (Newton's rings and Newton's law of motion/ viscosity/resistance) that he can be regarded as the greatest contributor to ... are divided into liquids and gases A liquid is hard to compress and as in the ancient saying ‘Water takes the shape of the vessel containing it’, it changes its shape according to the shape of ... lo6) (m2/s x106) Stokes’ equation, to be stated in Section 9.3.3, is utilised for measuring the viscosity, it is named after him), while its 1 / 100th part is 1 cSt (centistokes) Thus I s t

Ngày tải lên: 22/10/2012, 10:59

... changes according to its height, it is necessary to take its depth into account Furthermore, even in the case of relative rest (e.g the case where the fluid is stable relative to its vessel even ... to water pressure, such as the bank of a dam, the sluice gate of a dam or the wall of a water tank? How large must the torque be to open the sluice gate of a dam? What is the force required to ... closed at one end which is free to move, but the other end is rigidly fixed to the frame When the pressure enters from the fixed end, the cross-section tends to become circular so the free end

Ngày tải lên: 22/10/2012, 10:59

... we had to trust mainly to Rankine's text books Occasionally in the higher classes he would forget all about having to lecture and after waiting for ten minutes or so, we sent the janitor to tell ... formula or other and say it was wrong He then went up to the blackboard to prove this He wrote on the board with his back to us, talking to himself, and every now and then rubbed it all out and ... makes a rotary ’ In general, vector with the following components x, y, z for vector V (components x, y, z are u, v, w) is called the rotation or curl of vector V, which can be written as rot

Ngày tải lên: 22/10/2012, 10:59

... the top of the steep slope, and it increases towards the bottom This is because the potential energy increases and kinetic energy decreases at the top, and the opposite occurs at the bottom ... 5.9 Pitot's first experiment Fig 5.10 Pitot tube Trang 12(5.17) In a parallel flow, the static pressure pA is the same on the streamline adjacent to A and is detected by hole C normal to the ... is called a weir A weir is used to adjust the flow rate Trang 16A flying baseball can simply be caught with a glove A moving automobile, however, is difficult to stop in a short time (Fig 5.16)

Ngày tải lên: 22/10/2012, 10:59

... is found that the shearing stress due to the turbulent flow is proportional to pu’u’ Reynolds, by substituting u = ti + u’, u = 8 + u’ into the Navier-Stokes equation, performed an averaging ... neighbouring molecules in addition to the force studied by Euler to find the equation of motion of fluid Thereafter, through research by Cauchy, Poisson and Saint- Venant, Stokes derived the present equations, ... diffusion of vorticity becomes larger, too In the Navier-Stokes equations, the convective acceleration in the inertial term is non-linear2 Hence it is difficult to obtain an analytical solution for

Ngày tải lên: 22/10/2012, 10:59

... direction is also produced The total head loss hb is expressed by the following equation: V2 Here, c b is the total loss factor, and [ is the loss factor due to the bend effect The values of ... British texts use 4f in this equation Since friction factor f = 1/4, it is essential to check the definition to which a value of friction factor refers The symbol used is not a reliable guide ... 16Table 7.1 Loss factor [ for bends (smooth wall Re = 225 000, coarse wall face Re = 146 000) bend In a bend, in addition to the head loss due to pipe friction, a loss due to the change in flow

Ngày tải lên: 22/10/2012, 10:59

... proportional to the square of the circular velocity r o of that section, and the friction coefficient is f, the torque IT; due to this surface friction is as follows: Assuming f = f f , the torque ... subject to a force from the surrounding fluid When a flat plate is placed in the flow direction, it is only subject to a force in the downstream direction A wing, however, is subject to the ... inclined to the flow as shown in Fig 9.2 In general, the force R acting on a body is resolved into a component D in the flow direction U and the component L in a direction normal to U The former

Ngày tải lên: 22/10/2012, 10:59

... not feasible to have the ratios of all such corresponding forces simultaneously equal, it will suffice to identify those forces that are closely related to the respective flows and to have them ... function is called dimensional analysis If a phenomenon is too complicated to derive a formula describing it, dimensional analysis can be employed to identify groups of variables which would appear in ... groups can be constructed allowing numerical calculations to be conducted Trang 2In order to perform the dimensional analysis, it is convenient to use the n theorem Consider a physical phenomenon having

Ngày tải lên: 22/10/2012, 10:59

... called the Pitot tube coefficient, which may be taken as having value 1 for a standard-type Pitot tube However, when compressibility is to be taken into account, refer to Section 13.4 A Pitot tube ... commonly used standard Pitot tube (also called a Pitot-static tube) The flow velocity is given by the following equation from total pressure p1 and static pressure p z , both to be measured as in ... the total flow rate is obtained from the product of the mean velocity and the section area Apart from the standard type, there are various other types of Pitot tube, as follows Cylinder-type Pitot

Ngày tải lên: 22/10/2012, 10:59

... the total tem- From eqns (13.23) and (13.38), (1 3.39) This is applicable to a body placed in the flow, e.g between the stagnation point of a Pitot tube and the main flow Correction to a Pitot ... equation, the Mach number M corresponding to a density change of 5% is approximately 0.3 For this reason steady flow can be treated as incompressible flow up to around Mach number 0.3 Now, consider ... as shown in Fig 13.2(c), producing a Mach wave normal to the flow direction When u > a, i.e M > 1, the wavefronts are quite unable to propagate upstream as in Fig 13.2(d), but flow downstream

Ngày tải lên: 22/10/2012, 10:59

... pressurised pipe begins to discharge backwards into the tank at velocity v The pressure reverts to the original tank pressure po, and the pipe, too, begins to contract to its original state The ... comprising pipe line and tank changed (from 0 to p,, say), it is desirable to know the response of the outlet pressure p2 Assuming a pressure loss Ap due to tube friction, with instantaneous flow ... motive power, but recently it has been utilised for transmitting or automatically controlling power too High-pressure fluid has to be used in these systems for high speed and good response Consequently

Ngày tải lên: 22/10/2012, 10:59

... than to obtain the approximate solution numerically For a compressible fluid, it is further necessary to solve the equation of state and the energy equation simultaneously with respect to the ... it has become popular to solve flow problems numerically By such means it is now possible to follow a kaleidoscopic change of flow This field of engineering is referred to as numerical fluid ... calculated by using this method." One of the methods used to solve the compressible Navier-Stokes equation taking the viscosity into account is the IAF (Implicit Approximate Fig 15.9 Equi-Mach

Ngày tải lên: 22/10/2012, 10:59

... develop These vortices act to increase the lift necessary for a high-speed aircraft to undertake low-speed flight Plate 7 6 and Fig 16.6' visualise the flow around an automobile by the smoke method ... due to the change in density (temperature) The interference method, which uses the fact that the number of interference fringes is proportional to the difference in density, is mostly applied to ... applied to air flow For free surface water flow, the stereophotography method is used The unevenness of a liquid surface is stereophotographed to determine the difference in the height of the liquid

Ngày tải lên: 22/10/2012, 10:59

... the bottom row of tabs have an hierarchical relationship with the top row In that case two rows of tabs are fine, but be sure to indicate that the bottom row is directly related to the top row ... rows with the bottom row directly related to the top row The active tab is clearly indicated and the 2nd row is visually distinct Adobe attempts to convert the last crumb into a header, perhaps ... users to be focussed on your video make sure that there are minimal distractions Autoplay or Not? Sites handle this issue differently I would suggest to you to let a movie preload but to not

Ngày tải lên: 06/11/2012, 13:48

... induce him to Trang 19face independently the actual problems of philosophy as they appearedto his own time; he began also to direct his attention to the history ofphilosophy, and thus to call in ... increase discus-to their number does not seem discus-tohave occurred to him The only modifications he introduces are prima-rily due to the need of systematising them, to weaving them into onetexture ... General Introduction to Hegel’s System J.B Baillie Macmillian, New York and London 1901 Batoche Books Kitchener 1999 Trang 3Preface 5Chapter I: Introduction 9 Chapter II: First Stage—From 1797 to

Ngày tải lên: 06/11/2012, 15:51

... inexpensive way to collect anecdotal evidence and gather customer opinions and preferences 2 Focus groups In focus groups, a moderator uses a scripted series of questions or topics to lead a discussion ... yield valuable insights into customer attitudes and areexcellent ways to uncover issues related to new products or service development 4 Observation Individual responses to surveys and focus groups ... study’s group of participants — has to be just the right size Too large a sample costs too much, and too small a sample offers inaccurate results You also need to make sure you have the right samples

Ngày tải lên: 08/11/2012, 09:25

... motivational factors to Herzberg's factor theory The highest ranked motivator, interesting work, is a motivator factor The second ranked motivator, good wages is a hygiene factor Herzberg, Mausner, ... esteem factor The number four ranked motivator, job security, is a safety factor Therefore, according to Maslow (1943), if managers wish to address the most important motivational factor of Centers' ... Herzberg's work categorized motivation into two factors: motivators and hygienes (Herzberg, Mausner, & Snyderman, 1959) Motivator or intrinsic factors, such as achievement and recognition,

Ngày tải lên: 28/01/2013, 18:01

... Provider is to : [1.5]deployment descriptors, and package components into modules c) customize deployment descriptor elements, and install deployment units on servers b) assemble modules into larger ... assembler is to : [1.5] deployment descriptors, and package components into modules c) customize deployment descriptor elements, and install deployment units on servers b) assemble modules into larger ... information deployment descriptors, and package components into modules c) Customize deployment descriptor elements, and install deployment units on servers. b) Assemble modules into larger deployment

Ngày tải lên: 09/04/2013, 09:10

... causes to be communicated, delivered, or transmitted, or attempts to communicate, deliver, transmit or cause to be communicated, delivered, or transmitted the same to any person not entitled to receive ... paragraph y of section 11 of the Atomic Energy Act of 1954, with reason to believe that such information so obtained could be used to the injury of the United States, or to the advantage of any foreign ... Reconnaissance Reconnaissance refers to the preparatory phase where an attacker seeks to gather as much information as possible about a target of evaluation prior to launching an attack It involves

Ngày tải lên: 08/07/2013, 01:27

... and cylinder skewing and sector-based sparing with one spare sector per track. This needs to be accounted for in mapping logical blocks to the physical sectors. Adding all these factors results in the ... 97560 sector size 256 bytes 512 bytes cylinders 1449 1962 tracks per cylinder 8 19 data sectors per track 113 72 number of zones 1 1 track skew 34 sectors 8 sectors cylinder skew 43 sectors 18 sectors revolution ... specifications, since the only alternative is to determine them experimentally. The information required to determine how much power to apply to the pivot motor and for how long on a particular seek...

Ngày tải lên: 12/09/2012, 14:16