introduction to thermal systems engineering thermodynamics, fluid mechanics, and heat transfer

Michael J. Moran The Ohio State University Howard N. Shapiro Iowa State University of Science and Technology Bruce R. Munson Iowa State University of Science and Technology David P. DeWitt Purdue University John Wiley & Sons, Inc. Introduction to Thermal Systems Engineering: Thermodynamics, Fluid Mechanics, and Heat Transfer fm.qxd 6/27/02 12:50 Page i Acquisitions Editor Joseph Hayton Production Manager Jeanine Furino Production Editor Sandra Russell Senior Marketing Manager Katherine Hepburn Senior Designer Harold Nolan Production Management Services Suzanne Ingrao Cover Design Howard Grossman Cover Photograph © Larry Fleming. All rights reserved. This book was typeset in 10/12 Times Roman by TechBooks, Inc. and printed and bound by R. R. Donnelley and Sons (Willard). The cover was printed by The Lehigh Press. The paper in this book was manufactured by a mill whose forest management programs include sustained yield harvesting of its timberlands. Sustained yield harvesting principles ensure that the number of trees cut each year does not exceed the amount of new growth. This book is printed on acid-free paper. ϱ Copyright © 2003 by John Wiley & Sons, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (508) 750-8400 fax (508) 750-4470. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc. 605 Third Avenue, New York, NY 10158-0012, (212) 850-6008, E-mail: PERMREQ@WILEY.COM. To order books or for customer service call 1-800-CALL-WILEY(225-5945). ISBN 0-471-20490-0 Printed in the United States of America. 10987654321 fm.qxd 6/27/02 12:50 Page ii O ur objective is to provide an integrated introductory presentation of thermodynamics, fluid mechanics, and heat transfer. The unifying theme is the application of these principles in thermal systems engineering. Thermal systems involve the storage, transfer, and conversion of en- ergy. Thermal systems engineering is concerned with how energy is utilized to accomplish beneficial functions in industry, transportation, the home, and so on. Introduction to Thermal Systems Engineering: Thermo- dynamics, Fluid Mechanics, and Heat Transfer is intended for a three- or four-credit hour course in thermodynamics, fluid mechanics, and heat transfer that could be taught in the second or third year of an engineering curriculum to students with appropriate background in elementary physics and calculus. Sufficient material also is included for a two-course sequence in the thermal sciences. The book is suitable for self-study, including reference use in engineering practice and preparation for professional en- gineering examinations. SI units are featured but other commonly employed engineering units also are used. The book has been developed in recognition of the team- oriented, interdisciplinary nature of engineering practice, and in recognition of trends in the engineering curriculum, including the move to reduce credit hours and the ABET- inspired objective of introducing students to the common themes of the thermal sciences. In conceiving this new presentation, we identified those critical subject areas needed to form the basis for the engineering analysis of thermal systems and have provided those subjects within a book of manageable size. Thermodynamics, fluid mechanics, and heat transfer are presented following a traditional approach that is familiar to faculty, and crafted to allow students to master funda- mentals before moving on to more challenging topics. This has been achieved with a more integrated presentation than available in any other text. Examples of integration include: unified notation (symbols and definitions); engaging case- oriented introduction to thermodynamics, fluid mechanics, and heat transfer engineering; mechanical energy and thermal energy equations developed from thermodynamic principles; thermal boundary layer concept as an exten- sion of hydrodynamic boundary layer principles; and more. Features especially useful for students are: • Readable, highly accessible, and largely self- instructive presentation with a strong emphasis on engineering applications. Fundamentals and applications provided at a digestible level for an introductory course. • An engaging, case-oriented introduction to thermal systems engineering provided in Chapter 1. The chapter describes thermal systems engineering gen- erally and shows the interrelated roles of thermody- namics, fluid mechanics, and heat transfer for ana- lyzing thermal systems. • Generous collection of detailed examples featuring a structured problem-solving approach that encour- ages systematic thinking. • Numerous realistic applications and homework prob- lems. End-of-chapter problems classified by topic. • Student study tools (summarized in Sec. 1.4) include chapter introductions giving a clear statement of the objective, chapter summary and study guides, and key terms provided in the margins and coordinated with the text presentation. • A CD-ROM with hyperlinks providing the full print text plus additional content, answers to selected end-of-chapter problems, short fluid flow video clips, and software for solving problems in thermodynamics and in heat transfer. • Access to a website with additional learning resources: http://www.wiley.com/college/moran Features especially useful for faculty are: • Proven content and student-centered pedagogy adapted from leading textbooks in the respective disciplines: M.J. Moran and H.N. Shapiro, Fundamentals of Engineering Thermodynamics, 4 th edition, 2000. B.R. Munson, D.F. Young, and T.H. Okiishi, Fundamentals of Fluid Mechanics, 4 th edition, 2002. F.P. Incropera and D.P. DeWitt, Fundamentals of Heat and Mass Transfer, 5 th edition, 2002. • Concise presentation and flexible approach readily tailored to individual instructional needs. Topics are carefully structured to allow faculty wide latitude in choosing the coverage they provide to students—with no loss in continuity. The accom- panying CD-ROM provides additional content that allows faculty further opportunities to customize their courses and/or develop two-semester courses. Preface iii fm.qxd 6/27/02 12:50 Page iii iv Preface • Highly integrated presentation. The authors have worked closely as a team to ensure the material is presented seamlessly and works well as a whole. Special attention has been given to smooth transitions between the three core areas. Links between the core areas have been inserted throughout. • Instructor’s Manual containing complete, detailed solutions to all the end-of-chapter problems to assist with course planning. A Note on the Creative Process How did four experienced authors come together to develop this book? It began with a face-to-face meeting in Chicago sponsored by our Publisher. It was there that we developed the broad outline of the book and the unifying thermal systems engineering theme. At first we believed it would be a straightforward task to achieve our objectives by identifying the core topics in the respective subject areas and adapting material from our previous books to provide them concisely. We quickly found that it was easier to agree on overall objectives than to achieve them. Since we come from the somewhat different technical cultures of thermo- dynamics, fluid mechanics, and heat transfer, it might be expected that challenges would be encountered as the author team reached for a common vision of an integrated book, and this was the case. Considerable effort was required to harmonize different viewpoints and writing styles, as well as to agree on the breadth and depth of topic coverage. Building on the good will generated at our Chicago meeting, collaboration among the authors has been extraordinary as we have taken a problem-solving approach to this project. Authors have been open and mutually supportive, and have shared com- mon goals. Concepts were honed and issues resolved in weekly telephone conferences, countless e-mail ex- changes, and frequent one-to-one telephone conversations. A common vision evolved as written material was exchanged between authors and critically evaluated. By such teamwork, overlapping concepts were clarified, links between the three disciplines strengthened, and a single voice achieved. This process has paralleled the engineer- ing design process we describe in Chapter 1. We are pleased with the outcome. We believe that we have developed a unique, user- friendly text that clearly focuses on the essential aspects of the subject matter. We hope that this new, concise introduction to thermodynamics, fluid mechanics, and heat transfer will appeal to both students and faculty. Your suggestions for improvement are most welcome. Acknowledgments Many individuals have contributed to making this book better than it might have been without their participation. Thanks are due to the following for their thoughtful com- ments on specific sections and/or chapters of the book: Fan-Bill Cheung (Pennsylvania State University), Kirk Christensen (University of Missouri-Rolla), Prateen V. DeSai (Georgia Institute of Technology), Mark J. Holowach (Pennsylvania State University), Ron Mathews (University of Texas-Austin), S. A. Sherif (University of Florida). Organization and topical coverage also bene- fited from survey results of faculty currently teaching thermal sciences courses. Thanks are also due to many individuals in the John Wiley & Sons, Inc., organization who have contributed their talents and efforts to this book. We pay special recog- nition to Joseph Hayton, our editor, who brought the author team together, encouraged its work, and provided resources in support of the project. April 2002 Michael J. Moran Howard N. Shapiro Bruce R. Munson David P. DeWitt fm.qxd 6/27/02 12:50 Page iv THERMO What Is Thermal Systems Engineering? 1 1.1 Getting Started 1 1.2 Thermal System Case Studies 3 1.3 Analysis of Thermal Systems 7 1.4 How to Use This Book Effectively 9 Problems 11 Getting Started in Thermodynamics: Introductory Concepts and Definitions 14 2.1 Defining Systems 14 2.2 Describing Systems and Their Behavior 16 2.3 Units and Dimensions 19 2.4 Two Measurable Properties: Specific Volume and Pressure 21 2.5 Measuring Temperature 23 2.6 Methodology for Solving Problems 26 2.7 Chapter Summary and Study Guide 27 Problems 28 Using Energy and the First Law of Thermodynamics 31 3.1 Reviewing Mechanical Concepts of Energy 31 3.2 Broadening Our Understanding of Work 33 3.3 Modeling Expansion or Compression Work 36 3.4 Broadening Our Understanding of Energy 40 3.5 Energy Transfer by Heat 41 3.6 Energy Accounting: Energy Balance for Closed Systems 43 3.7 Energy Analysis of Cycles 51 3.8 Chapter Summary and Study Guide 54 Problems 55 Evaluating Properties 59 4.1 Fixing the State 59 Evaluating Properties: General Considerations 60 4.2 p-v-T Relation 60 4.3 Retrieving Thermodynamics Properties 64 4.4 p-v-T Relations for Gases 79 Evaluating Properties Using the Ideal Gas Model 81 4.5 Ideal Gas Model 81 4.6 Internal Energy, Enthalpy, and Specific Heats of Ideal Gases 83 4.7 Evaluating ⌬u and ⌬h of Ideal Gases 85 4.8 Polytropic Process of an Ideal Gas 89 4.9 Chapter Summary and Study Guide 91 Problems 91 Control Volume Analysis Using Energy 96 5.1 Conservation of Mass for a Control Volume 96 5.2 Conservation of Energy for a Control Volume 99 5.3 Analyzing Control Volumes at Steady State 102 5.4 Chapter Summary and Study Guide 117 Problems 118 The Second Law of Thermodynamics 123 6.1 Introducing the Second Law 123 6.2 Identifying Irreversibilities 126 6.3 Applying the Second Law to Thermodynamic Cycles 128 6.4 Maximum Performance Measures for Cycles Operating between Two Reservoirs 131 v Contents 2 3 5 6 4 1 fm.qxd 6/27/02 12:50 Page v vi Contents 6.5 Carnot Cycle 136 6.6 Chapter Summary and Study Guide 137 Problems 137 Using Entropy 141 7.10 Introducing Entropy 141 7.20 Retrieving Entropy Data 143 7.30 Entropy Change in Internally Reversible Processes 149 7.40 Entropy Balance for Closed Systems 151 7.50 Entropy Rate Balance for Control Volumes 157 7.60 Isentropic Processes 162 7.70 Isentropic Efficiencies of Turbines, Nozzles, Compressors, and Pumps 166 7.80 Heat Transfer and Work in Internally Reversible, Steady-State Flow Processes 171 7.90 Accounting for Mechanical Energy 174 7.10 Accounting for Internal Energy 176 7.11 Chapter Summary and Study Guide 177 Problems 178 Vapor Power and Refrigeration Systems 185 Vapor Power Systems 185 8.10 Modeling Vapor Power Systems 185 8.20 Analyzing Vapor Power Systems—Rankine Cycle 187 8.30 Improving Performance—Superheat and Reheat 198 8.40 Improving Performance—Regenerative Vapor Power Cycle 202 Vapor Refrigeration and Heat Pump Systems 206 8.50 Vapor Refrigeration Systems 207 8.60 Analyzing Vapor-Compression Refrigeration Systems 209 8.70 Vapor-Compression Heat Pump Systems 217 8.80 Working Fluids for Vapor Power and Refrigeration Systems 218 8.90 Chapter Summary and Study Guide 218 Problems 219 Gas Power Systems 223 Internal Combustion Engines 223 9.1 Engine Terminology 223 9.2 Air-Standard Otto Cycle 225 9.3 Air-Standard Diesel Cycle 230 Gas Turbine Power Plants 234 9.4 Modeling Gas Turbine Power Plants 234 9.5 Air-Standard Brayton Cycle 235 9.6 Regenerative Gas Turbines 243 9.7 Gas Turbines for Aircraft Propulsion (CD-ROM) 247 9.8 Chapter Summary and Study Guide 247 Problems 247 Psychrometric Applications (CD-ROM) 250 All material in Chapter 10 is available on the CD-ROM only. 10.1 Introducing Psychrometric Principles 10.2 Evaluating the Dew Point Temperature 10.3 Psychrometers: Measuring the Wet-Bulb and Dry-Bulb Temperatures 10.4 Psychrometric Charts 10.5 Analyzing Air-Conditioning Processes 10.6 Cooling Towers 10.7 Chapter Summary and Study Guide Problems FLUIDS Getting Started in Fluid Mechanics: Fluid Statics 251 11.1 Pressure Variation in a Fluid at Rest 251 11.2 Measurement of Pressure 255 11.3 Manometry 256 11.4 Mechanical and Electronic Pressure and Measuring Devices 259 11.5 Hydrostatic Force on a Plane Surface 260 11.6 Buoyancy 264 11.7 Chapter Summary and Study Guide 265 Problems 265 8 10 11 7 9 fm.qxd 6/27/02 12:50 Page vi Contents vii The Momentum and Mechanical Energy Equations 269 12.1 Fluid Flow Preliminaries 269 12.2 Momentum Equation 272 12.3 Applying the Momentum Equation 273 12.40 The Bernoulli Equation 278 12.50 Further Examples of Use of the Bernoulli Equation 280 12.60 The Mechanical Energy Equation 282 12.70 Applying the Mechanical Energy Equation 283 12.80 Compressible Flow (CD-ROM) 286 12.90 One-dimensional Steady Flow in Nozzles and Diffusers (CD-ROM) 286 12.10 Flow in Nozzles and Diffusers of Ideal Gases with Constant Specific Heats (CD-ROM) 286 12.11 Chapter Summary and Study Guide 287 Problems 287 Similitude, Dimensional Analysis, and Modeling 293 13.10 Dimensional Analysis 293 13.20 Dimensions, Dimensional Homogeneity, and Dimensional Analysis 294 13.30 Buckingham Pi Theorem and Pi Terms 297 13.40 Method of Repeating Variables 298 13.50 Common Dimensionless Groups in Fluid Mechanics 301 13.60 Correlation of Experimental Data 302 13.70 Modeling and Similitude 304 13.80 Chapter Summary and Study Guide 308 Problems 309 Internal and External Flow 313 Internal Flow 313 14.10 General Characteristics of Pipe Flow 314 14.20 Fully Developed Laminar Flow 315 14.30 Laminar Pipe Flow Characteristics (CD-ROM) 316 14.40 Fully Developed Turbulent Flow 316 14.50 Pipe Flow Head Loss 317 14.60 Pipe Flow Examples 322 14.70 Pipe Volumetric Flow Rate Measurement (CD-ROM) 325 External Flow 325 14.80 Boundary Layer on a Flat Plate 326 14.90 General External Flow Characteristics 330 14.10 Drag Coefficient Data 332 14.11 Lift 335 14.12 Chapter Summary and Study Guide 337 Problems 338 HEAT TRANSFER Getting Started in Heat Transfer: Modes, Rate Equations and Energy Balances 342 15.10 Heat Transfer Modes: Physical Origins and Rate Equations 342 15.20 Applying the First Law in Heat Transfer 348 15.30 The Surface Energy Balance 351 15.40 Chapter Summary and Study Guide 355 Problems 356 Heat Transfer by Conduction 359 16.10 Introduction to Conduction Analysis 359 16.20 Steady-State Conduction 362 16.30 Conduction with Energy Generation 373 16.40 Heat Transfer from Extended Surfaces: Fins 377 16.50 Transient Conduction 385 16.60 Chapter Summary and Study Guide 395 Problems 397 Heat Transfer by Convection 405 17.10 The Problem of Convection 405 Forced Convection 412 17.20 External Flow 412 17.30 Internal Flow 423 13 14 15 17 16 12 fm.qxd 6/27/02 12:50 Page vii viii Contents Free Convection 438 17.40 Free Convection 438 Convection Application: Heat Exchangers 446 17.50 Heat Exchangers 446 17.60 Chapter Summary and Study Guide 456 Problems 458 Heat Transfer by Radiation 468 18.1 Fundamental Concepts 468 18.2 Radiation Quantities and Processes 470 18.3 Blackbody Radiation 473 Spectrally Selective Surfaces 479 18.4 Radiation Properties of Real Surfaces 479 Radiative Exchange Between Surfaces in Enclosures 489 18.5 The View Factor 489 18.6 Blackbody Radiation Exchange 492 18.7 Radiation Exchange between Diffuse-Gray Surfaces in an Enclosure 495 18.8 Chapter Summary and Study Guide 502 Problems 503 Appendices 511 Index to Property Tables and Figures 511 Index 557 18 A fm.qxd 6/27/02 12:50 Page viii Things You Should Know Version 1 05-31-02 Page 1 of 7 Things You Should Know About Interactive Thermodynamics (IT) and Interactive Heat Transfer (IHT) What is the software all about? IT and IHT provided on your CD-ROM are Windows-based, general-purpose, nonlinear equation solvers with built-in functions for solving thermodynamics and heat transfer problems. The packages were designed for use with the texts Fundamentals of Engineering Thermodynamics (Moran & Shapiro, 4 th Ed., 2000, Wiley) and Introduction to Heat Transfer (Incropera & DeWitt, 4 th Ed., 2002, Wiley), respectively. The equation numbering, text section/topic identification, and content, are specific to those texts. However, the software is also well suited for use with Introduction to Thermal Systems Engineering (ITSE). It is our purpose here to identify features of IT and IHT that will help you make good use of the software in solving thermodynamics and heat transfer problems. Why use IT and IHT? You should consider IT and IHT as productivity tools to reduce the tediousness of calculations, and as learning tools to permit building models and exploring influences of system parameters. Use the software as you would a hand calculator to check solutions. Solve systems of equations that otherwise would require iterative hand calculations. Sweep across the value of a parameter to generate a graph. But, best of all, use the special features of the packages identified below that will greatly facilitate your problem solving assignments. For thermodynamics applications, you will find IT especially helpful for retrieving thermodynamic property data while solving a problem that requires one numerical solution, or for varying parameters to investigate their effects. For heat transfer applications, you will find IHT especially helpful for solving problems associated with these topics: transient conduction using the lumped capacitance method and one-term series analytical solutions; estimating convection coefficients using correlations requiring thermophysical properties of fluids as a function of temperature; and blackbody radiation functions. Things You Should Know Version 1 05-31-02 Page 2 of 7 Getting Started with IT and IHT When you first start up IT and IHT, you will be asked whether you want to run the Tutorial. If you are new to the software, you should go through the Tutorial so that you can build these basic skills: • enter equations from the keyboard, • solve equation sets with an understanding of Initial Guesses and solver behavior, • perform Explore and Graph operations, and • understand general features of the solver Intrinsic Functions . For IT, the Tutorial, is self-contained and provides you with all that you need to learn the basic features of the software. After working through the tutorial you will be able to solve basic thermodynamic problems, vary parameters, and make graphs. Your skills with IT will serve you as well with IHT since their architecture, solver engine and other key features are similar. For IHT, the Tutorial, while labeled as Example 1.6, is based on ITSE Example 15.3, Curing a Coating with a Radiant Source. Step-by-step instructions will lead you through the construction of the model, solution for the unknown variables, and graphical representation of a parametric study. You should become familiar with the Help Index, which serves as the User’s Manual for the software. You should read the first section, IHT Environment, so that you understand the structure of the software. Later we’ll introduce you to some special Intrinsic Functions. To find out more about using the software, you should go to the sections that follow entitled, IT: Some Special Tips or IHT: Some Special Tips. [...]... represent thermal systems Ice rinks, snow-making machines, and other recreational uses involve thermal systems In living things, the respiratory and circulatory systems are thermal systems, as are equipment for life support and surgical procedures Thermal systems involve the storage, transfer, and conversion of energy Energy can be stored within a system in different forms, such as kinetic energy and gravitational... of Thermal Systems In this section, we introduce the basic laws that govern the analysis of thermal systems of all kinds, including the three cases considered in Sec 1.2 We also consider further the roles of thermodynamics, fluid mechanics, and heat transfer in thermal systems engineering and their relationship to one another Important engineering functions are to design and analyze things intended to. .. study in thermodynamics, fluid mechanics, and heat transfer to strengthen your understanding of fundamentals and to acquire more experience in model building and solving applications-driven problems 1.4 How to Use This Book Effectively This book has several features and learning resources that facilitate study and contribute further to understanding 9 10 Chapter 1 What Is Thermal Systems Engineering? ... physics and chemistry, you were introduced to these laws In this book, we place the laws in forms especially well suited for use in thermal systems engineering and help you learn how to apply them 1.3.1 The Three Thermal Science Disciplines As we have observed, thermal systems engineering typically requires the use of three thermal science disciplines: thermodynamics, fluid mechanics, and heat transfer. .. t transfer Fl H ea Thermal Systems Engineering Analysis directed to Design Operations/Maintenance Marketing/Sales Costing • • • Heat Transfer Conduction Convection Radiation Multiple Modes s Fluid Mechanics Fluid statics Conservation of momentum Mechanical energy equation Similitude and modeling Figure 1.5 The disciplines of thermodynamics, fluid mechanics, and heat transfer involve fundamentals and. .. practice of thermal systems engineering 1.4 How to Use This Book Effectively effects and lift/drag forces The concept of similitude is used extensively in scaling measurements on laboratory-sized models to full-scale systems Heat transfer is concerned with energy transfer as a consequence of a temperature difference As shown in Fig 1.5, there are three modes of heat transfer Conduction refers to heat transfer. .. from your background in physics and chemistry The roles of thermodynamics, fluid mechanics, and heat transfer in thermal systems engineering and their relationship to one another also are described The presentation concludes with tips on the effective use of the book chapter objective 1.1 Getting Started Thermal systems engineering is concerned with how energy is utilized to accomplish beneficial functions... applications for thermal systems engineering Electric power Cooling tower 1.2 Thermal System Case Studies system is a complex combination of fluid flow and heat transfer components that regulates the flow of blood and air to within the relatively narrow range of conditions required to maintain life In the next section, three case studies are discussed that bring out important features of thermal systems engineering. .. (up to eight characters), but different extensions (.dsk, eqd, and eqs) Remember to include all four files if you perform a copy -and- paste sequence to relocate the files from your CD-ROM to another drive on your computer Things You Should Know Version 1 05-31-02 Page 7 of 7 1 WHAT IS THERMAL SYSTEMS ENGINEERING? Introduction The objective of this chapter is to introduce you to thermal systems engineering. .. provide examples of complex thermal systems As in the case of hot water systems, the principles of thermodynamics, fluid mechanics, and heat transfer apply to the analysis and design of individual parts, components, and to the entire vehicle 1.2.3 Microelectronics Manufacturing: Soldering Printed-Circuit Boards Printed-circuit boards (PCBs) found in computers, cell phones, and many other products, are . home, and so on. Introduction to Thermal Systems Engineering: Thermo- dynamics, Fluid Mechanics, and Heat Transfer is intended for a three- or four-credit hour course in thermodynamics, fluid mechanics,. include: unified notation (symbols and definitions); engaging case- oriented introduction to thermodynamics, fluid mechanics, and heat transfer engineering; mechanical energy and thermal energy equations. from your background in physics and chemistry. The roles of thermodynamics, fluid mechanics, and heat transfer in thermal systems engineering and their relationship to one another also are described.