Computational modelling of a thermo-acoustic travelling wave engine

Abstract

An engine is being developed to utilise some of the heat of a wood-burning stove to produce a small quantity of electricity. The heat is used to maintain a temperature gradient in a regenerator consisting of very narrow passages in which the gas (air) is in intimate thermal contact with the material. By the thermo-acoustic principle, a strong sound wave can be developed if the regenerator is incorporated in an acoustic loop so that acoustic energy is returned to it and amplified. The excess power generated can be extracted by a linear alternator. This article describes a model of the thermal, acoustic and electrical processes, and a procedure for calculating the performance of a complete loop. Comparison of the computed results with data from three configurations of apparatus shows that the acoustic elements of the problem are quite accurately described. However, there are discrepancies between the calculated thermal and electrical parameters, and the limited measurements for a practically useful arrangement of the components.

Keywords

Thermo-acoustic engine travelling wave engine acoustic Stirling cycle

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