Under certain circumstances, a flow of heat through a system can give rise to acoustic oscillations, converting some of the heat to work. Natural vibrators maintained by heat flows have been studied since the 1770s. Some of the best‐known examples come from acoustics: the “singing flames” first investigated by Byron Higgins in 1777, the Sondhauss tube and the Rijke tube. Most experimenters in cryogenics have observed the “Taconis oscillations” that occur when a tube, closed at the top, is inserted into a liquid‐helium dewar. A group at Tsukuba has studied such oscillations quantitatively. Oscillations driven by heat also occur on a very large scale, in certain classes of variable stars.
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August 01 1985
‘Taconis oscillations,’ the oscillations of some variable stars, and a novel form of engine are all based on cycles that involve an intrinsically irreversible process and a broken thermodynamic symmetry.
Physics Today 38 (8), 50–58 (1985);
John Wheatley, Arthur Cox; Natural Engines. Physics Today 1 August 1985; 38 (8): 50–58. https://doi.org/10.1063/1.880985
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