Heat engines in finite time governed by master equations
作者:
Tova Feldmann,
Eitan Geva,
Ronnie Kosloff,
Peter Salamon,
期刊:
American Journal of Physics
(AIP Available online 1996)
卷期:
Volume 64,
issue 4
页码: 485-492
ISSN:0002-9505
年代: 1996
DOI:10.1119/1.18197
出版商: American Association of Physics Teachers
关键词: EFFICIENCY;ENERGY CONVERSION;HARMONIC OSCILLATORS;HEAT ENGINES;HEAT TRANSFER;IRREVERSIBLE PROCESSES;THERMODYNAMIC CYCLES;WORKING FLUIDS;05.70
数据来源: AIP
摘要:
A simple example of a four‐stroke engine operated in finite‐time is analyzed. The working medium consists of noninteracting two‐level systems or harmonic oscillators. The cycle of operation is analogous to a four‐strokeOttocycle. The only source of irreversibility is due to the finite rate of heat transfer between the working medium and the cold and hot baths. The dynamics of the working medium is governed by a master equation. The engine is shown to settle to a stable limit cycle forgivencontact periods with the hot and cold baths. The operation of the engine is analyzed subject to a fixed cycle time. The time allocation between the hot and cold branches that maximizes the work output is considered. Analytical results are obtained when the relaxation is very slow, very fast, or when the relaxation rates along the hot and cold branches are equal. Numerical results are presented for the general case. A maximization of the power with respect to the cycle time leads to a finite optimal cycling frequency provided the adiabatic branches are allotted finite durations.
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