Design and Optimization of Thermal Systems Episode 3 Part 7 doc

Many case studies are given by Ertas and Jones 1997 and the IEEE code of ethics is given by Dieter 2000 to indicate the basic issues involved and the types of ethical conflicts encounter

in the operating conditions, the user, ambient conditions, raw materials, and other unpredictable parameters are used to leave an acceptable margin of safety For instance, a dimension obtained as 2 cm from the feasible or optimal design may

be increased to 3 cm for safety, giving a factor of safety of 1.5, particularly if this dimension refers to the outer wall of a system and may fail Higher safety factors are used if damage to an operator may result from leakage of radiation, hot fluid, high-pressure gases, etc This is particularly true in the design of nuclear reac-tors, boilers, furnaces, and many other such systems where high temperatures and pressures arise Therefore, the design obtained on technical grounds is adjusted to account for safety of the user as well as of the materials and the system

Similarly, environmental concerns can affect the design Constraints are placed on the types of materials that can be used, on temperature and concen-tration of discharges into the environment, on maximum flow rates that may be used, on types and amount of solid waste, and so on For instance, chlorofluoro-carbons (CFCs) are not allowed because of their effect on the ozone layer The temperature of the cooling water (from the condensers of a power plant) that is discharged into a lake or a river is constrained to, say, within 10nC of the ambient water temperature by federal regulations This imposes an important constraint

on the design of the system Similarly, the concentration of pollutants and the flow rate of the fluid discharged into air are constrained by regulations to ensure

a clean environment Again, these aspects arise as additional constraints on the design and must be taken into account

The legal issues are often related to federal and state regulations on waste posal, zoning, procurement, transportation, security, permits, etc., and can generally

dis-be considered in terms of the cost incurred, since these involve additional ditures by a company Similarly, social issues can often be translated into costs for the company For instance, providing housing, health, and other benefits to the employees results in expenses for the firm Therefore, these aspects lead to financial constraints that may be quantified However, many aspects are not easy to account for, such as the social effects of layoffs resulting from a particular industrial develop-ment There may be substantial effect on the local level However, these aspects are largely considered at higher levels of management and affect the design only as far

expen-as the viability of the overall project is concerned National considerations, such expen-as those pertaining to defense, sometimes override the technical and economic aspects Items and materials that have to be imported may be substituted by those that are available in the domestic market Thus, constraints may be placed on the choice of materials, components, and subsystems to take these concerns into account

These additional constraints are usually considered after a feasible design has been obtained At this stage, the constraints due to the costs, safety, environ-ment, and other aspects are considered to ensure that these are not violated by the design However, some of these constraints may also be more effectively used

at earlier stages of the design process The temperature and pressure limitations arising from safety concerns, for instance, may be built into the design and opti-mization process The final design that is communicated to the management and fabrication facilities must satisfy all such additional constraints

11.3 PROFESSIONAL ETHICS

A topic that has come under considerable scrutiny in recent years is that of sional ethics This is due to the large number of cases that have been uncovered indicating lack of proper behavior, and resulting in damage to life and property

profes-Ethics refers to the principles that govern the conduct of an individual or groups

of people involved in a profession Every profession sets down its own code of ethics to provide rules of behavior that are proper, fair, and morally correct It

is important for individuals involved in a profession that is self-regulated, such

as engineering, to know the ethical behavior that is expected of them and to serve their integrity under various circumstances Though many recent cases have involved the legal and medical professions, mainly because of their direct impact on people, engineers are also concerned with many decisions that involve professional ethics Certainly, design is an area that has far-reaching implications for the profession and must, therefore, be carried out with strict adherence to ethical standards

pre-Ethics has its roots in moral philosophy, and the basic features are simply the moral values that govern personal behavior Some of the important aspects of proper conduct can be listed as follows:

1 Be fair to others

2 Respect the rights of others

3 Do not do anything illegal

4 Do not break contracts

5 Help others and avoid harming anyone

6 Do not cheat, steal ideas, or lie

On the basis of such a set of moral values, many professional societies such as the Institute of Electrical and Electronics Engineers (IEEE) and American Board

of Engineering Accreditation (ABET) have adopted appropriate codes of ethics that are expected to guide the members as well as companies if ethical problems arise

Most routine engineering activities do not involve ethical conflicts Since profit and growth are major driving forces in the engineering profession, most engineers are involved with pursuing these goals for advancement However, if their actions start infringing on the rights of others and may lead to harm to others, through damage to property or to individuals, it is important to balance self-interest against ethics and to follow the appropriate course of action In some cases, the choice is clear, but the individual may have to sacrifice his or her self-interest in order to do the proper thing An example of this is an engineer who designs a system, but finds that it has safety problems during testing It is obvious that the system must be redesigned to avoid these problems However, there may

be deadlines to be met, the job of the engineer may be on the line, others involved

in the design may try to downplay the problems and want to go ahead, and so

on Therefore, even a relatively straightforward problem like this one may lead

to a dilemma for the individuals concerned However, the correct procedure is to report the problems and redesign the system.

Many such ethical questions are faced by engineers, particularly those involved in the development of new processes, systems, and products Some of the common ethical situations that arise are

1 Preserving confidentiality

2 Giving proper credit to appropriate groups or individuals

3 Reporting data correctly

4 Meeting obligations to the public versus the employer

5 Acting in accord with personal conscience

6 Responding to inappropriate behavior by others in the company

Many readers may have already experienced some of the preceding tions Giving proper credit to different people involved in a project is always a touchy issue, but it is important to be fair to all Similarly, proprietary informa-tion must be maintained as confidential because access to such information or data is allowed only to a few individuals under the condition of confidentiality

situa-A subcontractor who is designing a component for a system manufactured by

a different organization is often provided with essential details on the system These details are for use in the design process and are not to be revealed to other parties who are not involved Correct reporting of data has been in the news a lot in the last few years, as some researchers have been found to falsify experi-mental results to downplay the side effects of the product and to claim important advances Several drugs and their manufacturers have been in the news lately due

to allegations of such wrongdoing When uncovered, these actions have led to large financial settlements and public ridicule

The issue of inappropriate behavior by others is a very difficult one and requires considerable care Suppose an engineer finds out that his company is violating federal regulations on dumping of chemical hazardous wastes Does he

or she simply ignore the problem? According to the code of ethics, this matter has

to be reported to the proper authorities This is known as whistle blowing and it

cannot be taken lightly It is necessary to be sure that the activity is illegal and is adversely affecting public safety or welfare Proper documentation is needed to support the accusation, and it must also be confirmed that management is aware

of the activities If the problem lies within the company and is a consequence of oversight, a simpler solution may be possible Otherwise, appropriate regulatory bodies may be contacted Whistle blowing obviously requires great moral cour-age, and the present position as well as the future advancement of anyone who undertakes this effort are at stake Such instances are rare, but they have been increasing and they test the professional code of ethics

In most cases where ethical conflicts need to be resolved, internal appeal processes are adequate These start with the immediate supervisor, or with some-one outside the region of conflict, and follow the internal chain of command Satis-factory documentation is crucial in such appeals Conflicts arise, for instance, due

to unfair treatment, improper credit being given, falsification of data, improper use of funds, etc Only if the internal appeal process is unsuccessful does one need to resort to external options These include contacting professional societies, the media, regulatory agencies, personal legal counsel, and other external sources for settling the conflict Many case studies are given by Ertas and Jones (1997) and the IEEE code of ethics is given by Dieter (2000) to indicate the basic issues involved and the types of ethical conflicts encountered in practice.

11.4 SOURCES OF INFORMATION

An important ingredient in design is availability of relevant information on a variety of topics that are needed for developing a successful design Informa-tion is needed to provide accurate data for the modeling and simulation of the system and to use past experience and results for help with the design process Without adequate information on previous design efforts and existing systems,

we could repeat past mistakes, spend time on obtaining information that is ily available, or generate designs that do not meet appropriate regulations and standards Therefore, it is crucial that we spend extensive effort on gathering the most accurate and up-to-date information available on all facets of the given design problem

read-The types of information needed for design are obviously functions of the system under consideration However, the information sought for the design of thermal systems is generally in the following main areas:

1 Material property data, including cost and availability

2 Design and operation of existing or similar systems and processes

3 Availability and cost of different types of components

4 Available computer software

5 Available empirical results, including heat transfer correlations, evant technical data, and characteristics of equipment

rel-6 Federal, state, and local regulations on safety and environment

7 Standards and specifications set by appropriate professional bodies

8 Current financial parameters, including rates of interest and inflation, different costs, and market trends

We have seen in earlier chapters that all this information is needed at ous stages of the design process to obtain the desired inputs as well as to evalu-ate the design Property data are particularly important because the accuracy of the simulation results, which are crucial to the design process, is determined by the data provided to the model Economic data are needed to evaluate costs, make economic decisions during design, and determine if a project is financially viable The design must meet the standards and regulations specified for the given pro-cess or application and, therefore, it is necessary to obtain accurate information

vari-on these Finally, informativari-on vari-on existing systems, software, and technical results helps in minimizing the effort and avoiding duplication of work

Throughout this book, references have been made to books, papers, and other publications that deal in depth with a particular topic or area Certainly, textbooks

in the areas of heat transfer, thermodynamics, and fluid mechanics are a good starting point for the design of thermal systems Similarly, text and reference books on numerical methods, engineering economics, optimization, and design are important sources of relevant information These can be used to provide the basic technical background needed for the various aspects that are involved in design Different methods for analyzing various processes and systems, includ-ing mathematical, numerical, and experimental techniques, are given in detail in such books, along with characteristic results Some information is also available

on common materials; components of interest in thermal systems such as pumps, compressors, and heat exchangers; and general features of standard systems, like air conditioners and diesel engines The references quoted in these books and papers may be further used to expand the source base However, for detailed information on material properties, applicable regulations, current economic parameters, existing systems, characteristics of available equipment, and current trends in industry, other sources of information are needed

There are two main types of sources of information for design These are

1 Public sources: Libraries, universities, research organizations,

depart-ments and agencies of the federal, state, and local government

2 Private sources: Manufacturing and supplying companies, banks,

pro-fessional societies, consultants, individuals, computer software nies, and membership and trade associations

compa-Public sources are extensively used because the information obtained is free

or relatively inexpensive Government reports and publications from departments such as commerce, defense, energy, and labor are very valuable because these pro-vide detailed information on results obtained, requirements and regulations, meth-ods used, material property data, and various other guidelines Patents issued also provide an excellent source of information on existing systems These are available from public sources, through libraries and the Internet Private sources are usually expensive, but a lot of information can be obtained through company brochures for advertising their products The specifications, cost, maintenance, servicing, and performance of available equipment can be obtained from the supplier In many cases, additional details on the materials used, tests performed, basic design of the component, and even samples can be obtained if one is interested in a particular item Though complete information on the component is generally confidential, enough information can be obtained to decide if a given item is appropriate for the system being designed Similar considerations apply to commercially avail-able software Extensive catalogs of manufacturers and suppliers are available

from listings such as Thomas Register of American Manufacturers The Internet

is another important and expanding source of such information

Most engineering companies maintain their own libraries that contain books, technical magazines, journals, reports, information on their own products and systems, listing of suppliers, and so on In the present information age, they also

have access to information available in the public domain, through the Internet, library exchanges, and agreements with other research or professional establish-ments Such a collection may be large or small, depending on the size of the company itself, but the available methods of literature search and procurement make it a very important source of information In addition, results from earlier efforts, information on existing systems, properties of materials used in the past, information on relevant regulatory and legal aspects, and so on, as applicable to the given industry, are probably best stored here.

Therefore, there are many important sources of information on materials, detailed technical data, existing processes and systems, items available in the market, economic data, and on other inputs needed for design These may be listed as follows:

1 Handbooks

2 Encyclopedias

3 Monographs and books

4 Journals: technical and professional

McGraw-Hill’s Encyclopedia of Science and Technology is an example of such

reference books Similarly, handbooks are available on pumps, air ing, heat exchangers, material properties, industrial engineering, manufacturing,

condition-etc Marks’ Standard Handbook for Mechanical Engineering, also published by

McGraw-Hill, is an example A substantial amount of relevant and focused mation is generally available in such sources Listings of indexes and abstracts allow one to search for the appropriate source rapidly, particularly if the informa-tion exists in journals, translations, and published reports Technical and profes-sional journals are also good sources, though these are often either too detailed

infor-or too sketchy Nevertheless, these can be used effectively to narrow the search to specific and relevant sources of information The Internet is certainly one of the most important sources of information today

Thus, information that is a crucial factor in design may be obtained from a wide variety of sources Many of these are free or quite inexpensive, while others may be expensive However, the current techniques available for literature searches range from CD-ROM databases to the Internet, making it much less time consum-ing than before to cover much of the available field and determine what information

is available and at what cost It is desirable to obtain as much relevant information

as possible on the given application or system so that the design process is carried out efficiently and without repeating existing data or past mistakes

11.5 AN OVERVIEW OF DESIGN OF THERMAL SYSTEMS

Basic aspects In this book, we have considered the design and optimization of

systems in which thermal transport involving heat and mass transfer, fluid flow, and thermodynamics play a dominant role Many different types of thermal sys-tems, ranging from refrigeration, heating, and power systems to manufacturing and electronic equipment cooling systems, are employed as examples The com-plicated nature of these systems, particularly their typically nonlinear, transient, three-dimensional, geometrically complex, and combined-mode characteristics, leads to coupled systems of governing partial differential equations These are simplified through modeling to obtain algebraic equations and ordinary differ-ential equations in many cases Such models are combined with experimental results, material property data, and other available information, often using curve fitting, to obtain a complete model for the system This model is then used to simulate the system and obtain detailed results, which can be used for the design and optimization of the system Thus, modeling and simulation form the core of the design effort for thermal systems, and a successful completion of the project is closely linked with the accuracy and validity of the model This aspect of design

is stressed throughout the book

The design of a thermal system starts with a close look at the problem This involves determining what is given or fixed in the problem, what can be varied

to obtain an acceptable design, what the main requirements are, and what straints or limitations must be satisfied by the design This consideration leads to the problem formulation in terms of given quantities, design variables, require-ments, and constraints It also defines the feasible domain for the design The next step is to obtain a conceptual design to achieve the desired goals Different ideas for the system are considered based on what is presently in use, and innova-tive concepts are employed as well A particular conceptual design is chosen by employing simple estimates and contrasting different ideas

con-With the design problem formulated and a conceptual design chosen, we can now proceed to a detailed design process, the main steps of which are

1 Characterization of the physical system

2 Modeling

3 Simulation

4 Evaluation of different designs

5 Iteration to obtain an acceptable design

6 Optimization

7 Automation and control

8 Communication of the final design

Workable design Though all the preceding steps are involved in the

devel-opment of a successful design, modeling and simulation are particularly crucial because most of the relevant inputs for design and optimization are obtained from a simulation of the system using analytical, numerical, and experimental

approaches to study the model developed for the system Different types of els and simulation strategies are available to generate the inputs needed for design Even though the basic approach to modeling can be established and applied to common thermal processes and systems, modeling remains a very elusive and difficult element in the design process It involves simplification, approximation, and idealization to obtain a model that may be used to study the behavior of the actual physical system Creativity and experience are important ingredients in the development of a model A good understanding of the physical characteristics of the system and the basic processes that govern its behavior is essential in decid-ing what to neglect or how to approximate The governing equations are obtained based on the conservation principles for mass, momentum, and energy, taking these simplifications into account.

mod-A very important question that must be answered for a model is if it rately and correctly predicts the characteristics of the actual system This requires

accu-a detaccu-ailed vaccu-alidaccu-ation of the model accu-and estimaccu-ation of the accu-accuraccu-acy of the results obtained In many cases, simple models are first obtained by neglecting many effects that complicate the analysis These models are then improved by includ-ing additional effects and features to bring them closer to the real system This fine-tuning of the model is generally based on the simulation, experimental, and prototype testing results The model is used to study the system response and behavior under a wide variety of conditions, including those that go beyond the expected region of operation to establish safety limits and ensure satisfactory operation in real life Simulation results are also used to determine if a particular design, specified in terms of the design variables, satisfies the requirements and the constraints

All these ideas concerning problem formulation, conceptual design, ing, simulation, and design evaluation may then be put together for obtaining acceptable designs Different areas such as manufacturing, energy, transporta-tion, and air conditioning, where thermal systems are of interest, are considered

model-to apply the various steps in the design process It can again be seen that eling and simulation are at the very core of the design effort since the results obtained are used to choose the appropriate design variables, evaluate different designs, and obtain a domain of acceptable designs Many additional aspects, such as safety and environmental issues, may also be considered at this stage

mod-A unique solution is generally not obtained and several acceptable designs are often generated Thus, the systematic progression from problem formulation and conceptual design to an acceptable design is highlighted in the first five chapters Though relatively simple thermal systems are considered in many cases to present the methodology, much more complicated problems that typically arise in actual practice can be treated in a similar way Some actual industrial systems are con-sidered to demonstrate the use of this methodology

Optimization Economic considerations and optimization need to be

consid-ered to complete the design and optimization process Economic aspects are ously very important in most problems of practical interest and are of particular significance in optimization since minimization of costs and maximization of

obvi-profit are important criteria for an optimal design Economic considerations, such

as cost, return, payment, investment, depreciation, inflation, and time value of money, in the design process are discussed Examples are given to show how economic considerations can affect decisions on design in areas such as material selection, choice of components, energy source, and so on The importance of financial aspects in design cannot be exaggerated since the viability and success

of the project itself is usually determined by the profit, return, stock price, etc Again, several relatively simple situations are discussed to illustrate the approach for considering economic factors However, these ideas can easily be extended

to more complicated circumstances where several different considerations may arise and interact with each other

Optimization is discussed in detail to stress the crucial need to optimize thermal systems in today’s competitive international market The design process generally leads to a domain of acceptable designs with no unique solution Optimi-zation with respect to a chosen criterion or objective function narrows this domain substantially, as desired for a given application, so that the final design is chosen from a small range of design variables, making it close to a unique solution Many different strategies are available for optimization Search methods are particularly useful for thermal systems since discrete values of the variables are often encoun-tered and simulation is complicated and time consuming, making it necessary to limit the number of runs Methods such as Fibonacci and univariate searches are efficient and easy to use Hill climbing techniques can also be used with numeri-cally determined derivatives Calculus methods and geometric programming are useful if the simulation results are curve fitted to obtain continuous expressions to represent system characteristics Other methods such as linear and dynamic pro-gramming have limited use for thermal systems Efficient computer programs are available for most of the techniques presented here and may be used when dealing with the large and complicated systems encountered in actual practice

The choice of the optimization method is guided by the form in which the simulation results are available and how involved each simulation run is Several simple examples are employed here to illustrate the basic ideas and the tech-niques These may be extended easily to many of the more complicated problems discussed in earlier chapters and examples of practical thermal systems given in the book Typical large systems are considered first in terms of the components and subsystems, with the overall model and simulation scheme obtained by cou-pling the simpler submodels The complete model is simulated to obtain the char-acteristics and behavior of the system These results are then used for developing acceptable designs, followed by an optimal design There are obviously cases where an acceptable design is not obtained, with the given requirements and con-straints, or where acceptable designs lie within a narrow range of variables, mak-ing it unnecessary to optimize the system

Concluding remarks The design and optimization of thermal systems is an

important, though complicated, field Many different situations can arise in actual practice and may require specialized treatment However, the basic approach given in this book provides the general framework under which the design and

optimization of a thermal system may be undertaken Some modifications may

be necessary in a few cases and additional information pertaining to materials, economic parameters, regulations, available components, and so on, may have to

be obtained for specific applications Creativity and originality are also tant ingredients in design, particularly in the development of the concept and the model In engineering practice, commercially available software packages are often used for system simulation and optimization However, some of the software may be developed or programs in the public domain may be employed to provide the flexibility and versatility needed in many cases Additional aspects, such as safety and environmental issues, are of concern in most problems and are built into the decision-making The final design is communicated to the appropriate groups such as the management and fabrication facilities Depending on man-agement decisions, this could lead to prototype development, testing, marketing, and sales All these aspects are expected to be considered in the design projects included at the end of this chapter

impor-11.6 SUMMARY

This chapter concludes the presentation on the design and optimization of mal systems by considering some recent trends, particularly knowledge-based design aids, and some additional considerations Knowledge-based, or expert, systems, which use the expertise of people who are proficient in given areas, have been used effectively in several fields, such as medicine, chemical analysis, and mining In traditional design, such expertise is traditionally brought in by the designer, who uses his or her knowledge of the process, materials, and system to make decisions throughout the design process in order to obtain a realistic and practical design Expert systems use computer software based on artificial intel-ligence (AI) techniques to bring such considerations into the design process The basic components — expert knowledge and databases — in knowledge-based design methodology are discussed The advantages of this approach over tradi-tional design methods are indicated Several examples of thermal systems are taken to illustrate the use of this methodology These efforts are still recent and have not been employed to their full potential However, there is growing interest

ther-in these methods and many relevant techniques have been developed ther-in recent years to help convergence to a realistic acceptable or optimal design

This chapter also discusses the important topics of professional ethics, sources of information, and additional constraints These aspects arise in most engineering endeavors, but these are particularly significant for design because

of the innovative and creative ideas that are often involved Different sources of information are discussed, indicating methods to locate these and extract the rel-evant information from them Professional ethics can play a very significant role

in the development of the design, in the use of available information, in the mentation of the design, and in the progress of the entire project A brief discus-sion of the important issues is given Additional constraints that could affect the feasibility of a design are presented and discussed in the context of the material

imple-covered in the book These could be of crucial importance in many cases and could determine whether it is worthwhile to proceed with the implementation of a given design Finally, the chapter integrates all the ideas presented in this book as

an overview of the design of thermal systems and includes a few design projects

as problems

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Budd, T (2002) An Introduction to Object-Oriented Programming, Addison-Wesley,

Boston, MA.

Clark, K.L and McCabe, F.G (1984) Micro-Prolog: Programming in Logic,

Prentice-Hall, Englewood Cliffs, NJ.

Cox, B.J (1986) Object Oriented Programming An Evolutionary Approach,

Addison-Wesley, Reading, MA.

Dieter, G.E (2000) Engineering Design: A Materials and Processing Approach, 3rd ed.,

McGraw-Hill, New York.

Dixon, J.R (1986) Artificial intelligence and design: a mechanical engineering view,

AAAI, 86:872–877.

Ertas, A and Jones, J.C (1997) The Engineering Design Process, 2nd ed., Wiley, New York Giarratano, J.C and Riley, G.D (2005) Expert Systems: Principles and Programming, 4th

ed., Thompson Course Technology, Boston, MA.

Ghosh, A and Mallik, A.K (1986) Manufacturing Science, Wiley, New York.

Jackson, P (1999) Introduction to Expert Systems, 3rd ed., Addison Wesley, Boston, MA.

Jaluria, Y and Lombardi, D (1991) Use of expert systems in the design of thermal

equip-ment and processes, Res Eng Des., 2:239–253.

Jamalabad, V.R., Langrana, N.A., and Jaluria, Y (1994) Rule-based design of a materials

processing component, Eng Comp., 10:81–94.

Karwe, M.V and Jaluria, Y (1990) Numerical simulation of fluid flow and heat transfer

in a single screw extruder for non-Newtonian fluids, Numerical Heat Transfer,

17:167–190.

Ling, S.K.R., Steinberg, L., and Jaluria, Y (1993) MSG: a computer system for automated

modeling of heat transfer, AI EDAM, 7:287–300.

Lombardi, D., Jaluria, Y., and Viswanath, R (1992) Simulation of the transport processes

in a thermal manufacturing system using symbolic computation, Eng Appl Artif Intel., 5:155–166.

Luger, G.F and Stubblefield, W.A (1989) Artificial Intelligence and the Design of Expert Systems, Benjamin/Cummings, New York.

Michaeli, W (2004) Extrusion Dies for Plastics and Rubber: Design and Engineering Computations, 3rd ed., Hanser Gardner, Cincinnati, OH.

Rauwendaal, C (2002) Polymer Extrusion, 4th ed., Hanser Gardner, Cincinnati, OH.

Russo, M.F., Peskin, R.L., and Kowalski, A.D (1987) A Prolog-based expert system for

modeling with partial differential equations, Simulation, 49:150–157.

Rychener, M.D., Ed (1988) Expert Systems for Engineering Design, Academic Press,

Boston, MA.

Sriram, D and Fenves, S.J., Eds (1988) Knowledge-Based Expert Systems for ing, Computational Mechanics Publications, Ashurst Lodge, Southampton, UK Suh, N.P (1990) The Principles of Design, Oxford University Press, New York.

Engineer-Tong, C and Sriram, D (2007) Artificial Intelligence in Engineering Design, Academic

Press, Boston, MA.

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design of ingot casting processes, Eng Comp., 7:109–120.

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PROBLEMS

11.1 For any thermal system mentioned in Chapter 1, draw a simple sketch

of the system considered Give the main assumptions you made to obtain an appropriate mathematical model Justify these and discuss changes that you would make in order to improve the accuracy of your model In addition, considering yourself an expert, what expert knowl-edge would be worth including in the design process?

11.2 An expert system is to be developed for the solution of algebraic tions Using the information presented in Chapter 4, give a suitable tree structure for the storage and retrieval of the relevant expert knowledge Consider single and multiple equations, as well as linear and nonlinear systems Also, include the various methods available for solution

equa-11.3 List the important knowledge that may be used for developing an expert system for the design of a building air conditioning system The relevant information may be obtained from reference books, as out-lined in this chapter Of particular interest are current practice, avail-able equipment, and costs involved Be brief

11.4 For the design of a solar thermal energy storage system, using water for storage, choose a conceptual design and give the design variables Then discuss the expert knowledge that could be employed, in con-junction with the basic design process, to obtain an optimal, practical design of the system

11.5 Present the knowledge base for the design of a furnace for heat ment of steel rods as a tree structure Consider different types of fur-naces, different heat sources, and different configurations

treat-11.6 What would the material knowledge base for the design of an tronic cooling system consist of? Use the information given in earlier chapters on such systems and a few relevant references

elec-11.7 An expert system is to be developed for solving ordinary differential equations List the expert knowledge needed to solve an ODE, analyti-cally or numerically Also, present the tree structure for storing this knowledge Outline the scheme employed by the expert system to solve

a given ODE

11.8 You are working as an engineer in the testing division of a large pany The division is involved in testing and evaluating equipment from various subcontractors and recommending the best ones to the