Principles Of Thermodynamics

PRINCIPLES OF THERMODYNAMICS BY G. A. GOODENOUGH, M. E. PROFESSOR OF THERMODYNAMICS IN THE UNIVERSITY OF ILLINOIS SECOND EDITION, ItEVISED NEW YORK HENRY HOLT AND COMPANY 1914 COPYRIGHT, 1911 n Y HENKY HOLT AND COMPANY PREFACE THIS book is intended primarily for students of engineering. Its purpose is to provide a course in the principles of thermo dynamics that may serve as an adequate foundation for the advanced study of heat engines. As indicated by the title, emphasis is placed on the principles rather than on the appli cations of thermodynamics. In the chapters on the technical applications the underlying theory of various heat engines is quite fully developed. The discussion, however, is restricted to ideal cases, and questions that involve the design, operation, or performance of heat engines are reserved for a second volume. The arrangement of the subject matter and the method of presentation are the result of some twelve yeaiV experience in teaching thermodynamics. Briefly, the arrangement is as fol lows In the first six chapters, the fundamental laws are developed and the general equations of thermodynamics are derived. The laws of gases and gaseous mixtures are dis cussed in Chapters VII and VIII, and this discussion is fol lowed immediately by the technical applications in which gaseous media play a part. A discussion of the properties of saturated and superheated vapors is likewise followed by the technical applications that involve vapor media. Some of the features of the book to which attention may be directed are the following 1. The method of presenting the fundamental laws. In this treatment I have followed very closely the development in Bryans thermodynamics. Thesecond law is made identical with the law of degradation of energy, the connection between irreversibility and loss of availability is pointed out, and by means of the Carnot cycle a measure of availability is obtained. Entropy is then defined in terms of unavailable energy, and iii iv PREFACE from this fundamental definition the usual definition of the entropy of a non-isolated system as the integral I f is easily derived. By this method of presentation, a definite concep tion of the meaning and scope of the second law is obtained, and the difficulties that usually surround the definition of entropy are removed. 2. The discussion of saturated and superheated vapors. The experiments in the Munich laboratory and the researches of Professor Marks and Dr. Davis have furnished new and accurate data on the thermal properties of saturated and super heated steam. In Chapters X and XI a concise but fairly complete account of these important researches is given. Kno blauchs experiments on specific volumes have been correlated with the experiments on specific heat by means of the Clausius f . 2 relation j A T - r and equations for the specific heat, dpJ T d T J p entropy, energy, and heat content of superheated steam are thereby deduced. These results have not hitherto been pub lished. 3. The discussion of the flow of fluids and of throttling processes. The applications of the throttling process are so important from all points of view that a separate chapter is devoted to them. 4. The treatment of gaseous mixtures, Chapter VIII. An attempt is made to present in concise form the principles and methods required in the accurate analysis of the internal com bustion engine. 5. The note on theinterpretation of differential expressions, Art. 23. This important topic should be discussed fully in calculus, but experience shows that students rarely have a grasp of it. In thermodynamics the exact differential has extensive applications hence it seems desirable to include a rather complete explanation of exact and inexact differentials and their connection with tliermodynamic magnitudes. A thorough understanding of this article should enable the student to pursue the subsequent mathematical discussions with intel ligence and ease...