Literaturnachweis - Detailanzeige
Autor/inn/en | Arnaud, J.; Chusseau, L.; Philippe, F. |
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Titel | A simple model for Carnot heat engines. |
Quelle | In: American journal of physics, 78 (2010) 1, S. 106-110
PDF als Volltext |
Sprache | englisch |
Dokumenttyp | online; gedruckt; Zeitschriftenaufsatz |
ISSN | 0002-9505; 1943-2909 |
DOI | 10.1119/1.3225921 |
Schlagwörter | Modellversuch; Carnot-Prozess; Entropie; Physik; Wärmekraftmaschine; Modell; Modellierung |
Abstract | We discuss a model consisting of two reservoirs, each with N possible ball locations, at heights Eh and El_Eh in a gravitational field. The two reservoirs contain nh and nl weight 1 balls. Empty locations are treated as weight 0 balls. The reservoirs are shaken so that all possible ball configurations are equally likely to occur. A cycle consists of exchanging a ball randomly chosen from the higher reservoir and a ball randomly chosen from the lower reservoir. We relate this system to a heat engine and show that the efficiency, which is defined as the ratio of the average work produced to the average energy lost by the higher reservoir, is 1? El /Eh. When nl is comparable to nh, the efficiency is found to coincide with the maximum efficiency 1? Tl /Th, where the emperatures Tl and Th are defined from a simple expression for the entropy. We also discuss the evaluation of fluctuations and the history of the Carnot discovery. © 2010 American Association of Physics Teachers. |
Erfasst von | Arbeitsgruppe Didaktik der Physik, Universität Osnabrück |
Update | 2010/2 |