On the evolution of the definition of entropy from Clausius to today
- Massachusetts Inst. of Tech., Cambridge, MA (United States)
Carnot analyzed an engine operating between two reservoirs. Through a peculiar mode of reasoning, he found the correct optimum shaft work performed during a cyclic change of state of the engine. Clausius justified Carnot`s result by enunciating two laws of thermodynamics, and introducing the concept of entropy as a ratio of heat and temperature of a thermodynamic equilibrium state. By appropriate algebraic manipulations, in this paper the authors express Carnot`s optimum shaft work in terms of available energies or exergies of the end states of the reservoirs, and Clausius` entropy in terms of energy and available energy. Next, the authors consider the optimum shaft work performed during a cyclic change of state of an engine operating between a reservoir, and a system with fixed-amounts of constituents, and fixed-volume but variable temperature. The authors express the optimum shaft work in terms of the available energies of the end states, and Clausius` entropy in terms of energy and available energy. Formally, the entropy expression is identical to that found for the Carnot engine except for the difference in end states. Finally, the authors consider the optimum shaft work performed during a cyclic change of state of an engine operating between system A initially in any state A{sub 1} (thermodynamic equilibrium or not) and reservoir R. The authors call this optimum generalized available energy with respect to R, and use it together with energy to define an entropy of any state A{sub 1}. Again the authors observe that the expression for entropy is formally identical to the two given earlier except for the difference in end states.
- OSTI ID:
- 483929
- Report Number(s):
- CONF-961105-; ISBN 0-7918-1527-7; TRN: IM9726%%322
- Resource Relation:
- Conference: 1996 international mechanical engineering congress and exhibition, Atlanta, GA (United States), 17-22 Nov 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the ASME Advanced Energy Systems Division. AES-Volume 36; Bittle, R.R. [ed.] [Texas Christian Univ., Fort Worth, TX (United States)]; Duncan, A.B. [ed.] [Marquette Univ., Milwaukee, WI (United States)]; Fiszdon, J. [ed.] [Mankato State Univ., MN (United States)]; Garimella, S. [ed.] [Western Michigan Univ., Kalamazoo, MI (United States)]; Herold, K. [ed.] [Univ. of Maryland, College Park, MD (United States)]; Nutter, D.W. [ed.] [Univ. of Arkansas, Fayetteville, AR (United States)]; O`Neal, D. [ed.] [Texas A and M Univ., College Station, TX (United States)]; Shiva Prasad, B.G. [ed.] [Dresser-Rand, Painted Post, NY (United States)]; Den Braven, K. [ed.] [Univ. of Idaho, Moscow, ID (United States). Dept. of Mechanical Engineering]; PB: 550 p.
- Country of Publication:
- United States
- Language:
- English
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