Thermodynamics

xviii | PrefaceSpecial effort has been made to appeal to students’ natural curiosity andto help them explore the various facets of the exciting subject area of thermodynamics.The enthusiastic responses we have received from users ofprior editions—from small colleges to large universities all over the world—indicate that our objectives have largely been achieved. It is our philosophythat the best way to learn is by practice. Therefore, special effort is madethroughout the book to reinforce material that was presented earlier.Yesterday’s engineer spent a major portion of his or her time substitutingvalues into the formulas and obtaining numerical results. However, formulamanipulations and number crunching are now being left mainly to computers.Tomorrow’s engineer will need a clear understanding and a firm grasp ofthe basic principles so that he or she can understand even the most complexproblems, formulate them, and interpret the results. A conscious effort ismade to emphasize these basic principles while also providing students witha perspective of how computational tools are used in engineering practice.The traditional classical, or macroscopic, approach is used throughout thetext, with microscopic arguments serving in a supporting role as appropriate.This approach is more in line with students’ intuition and makes learningthe subject matter much easier.NEW IN THIS EDITIONAll the popular features of the previous editions are retained while new onesare added. With the exception of reorganizing the first law coverage andupdating the steam and refrigerant properties, the main body of the textremains largely unchanged. The most significant changes in this fifth editionare highlighted below.EARLY INTRODUCTION OF THE FIRST LAW OF THERMODYNAMICSThe first law of thermodynamics is now introduced early in the new Chapter2, “Energy, Energy Transfer, and General Energy Analysis.” This introductorychapter sets the framework of establishing a general understanding ofvarious forms of energy, mechanisms of energy transfer, the concept ofenergy balance, thermo-economics, energy conversion, and conversion efficiencyusing familiar settings that involve mostly electrical and mechanicalforms of energy. It also exposes students to some exciting real-world applicationsof thermodynamics early in the course, and helps them establish asense of the monetary value of energy.SEPARATE COVERAGE OF CLOSED SYSTEMSAND CONTROL VOLUME ENERGY ANALYSESThe energy analysis of closed systems is now presented in a separate chapter,Chapter 4, together with the boundary work and the discussion ofspecific heats for both ideal gases and incompressible substances. The conservationof mass is now covered together with conservation of energy innew Chapter 5. A formal derivation of the general energy equation is alsogiven in this chapter as the Topic of Special Interest.REVISED COVERAGE OF COMPRESSIBLE FLOWThe chapter on compressible flow that deals with compressibility effects(now Chapter 17) is greatly revised and expanded. This chapter now includes