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Title: エントロピーとカルノー熱機関の効率
Other Titles: Entropy and Efficiency of Carnot Engine
Authors: 濱田, 圭之助
Authors (alternative): Hamada, Keinosuke / 浜田, 圭之助
Issue Date: 29-Feb-1988
Publisher: 長崎大学教育学部
Citation: 長崎大学教育学部自然科学研究報告. vol.39, p.35-40; 1988
Abstract: Entropy is one of the thermodynamic functions, which is defined to be disorder. The second law of thermodynamics says that a natural change occurs to a direction of increase of entropy. However the Newton's dynamics says that an apple, for example, naturally drops to a direction of decrease of potential due to universal gravitation. The efficiency η of the Carnot engine is shown to be η = (Q1-Q2)/Q1=(T1-T2)/T1, where Q1 is the heat that the Carnot engine gets from high temperature heat resources, Q1-Q2 is the heat used for a real work, and T1 and T2 are high and low temperatures of heat resources. From the above equation, Q1/T1 = Q2/T2 = S is obtained. The constant S is called as entropy. However, the efficiency η of the Carnot engine should be η = {(Q1+Q2) - (Q3+Q4)}/(Q1+Q2+Q3+Q4), because the heats Q2, Q3 and Q4 are not used for works, but are necessary for operating the Carnot engine. In any case, the entropy has nothing to do with the disorder.
URI: http://hdl.handle.net/10069/32466
ISSN: 0386443X
Type: Departmental Bulletin Paper
Text Version: publisher
Appears in Collections:No. 39

Citable URI : http://hdl.handle.net/10069/32466

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