Theoretical Study on Standing Wave Thermoacoustic Engine

Abstract

Applications of thermoacoustic engines are not limited to driving pulse tube cryocoolers. The performance of a thermoacoustic engine is governed by various design parameters like type of resonator, stack geometry, frequency, type of working gas etc. and various operating parameters like heat input, charging pressure etc. It is very important to arrive at an optimum configuration of the engine for which a theoretical model is required. In the present work, a theoretical analysis, based on linear acoustic theory of a standing wave type half wavelength thermoacoustic engine is carried out using DeltaEC software. The system dimensions like length of resonator, stack, hot and cold heat exchangers are fixed with a helium-argon mixture as the working gas and a parallel plate type stack. Later on, two plate spacings, corresponding to helium-argon mixture and nitrogen gas, are used for carrying out analysis with helium, argon, nitrogen, carbon dioxide and helium-argon mixture as working gases of the system. The effect of charging pressure on the performance of the system is studied in terms of resonating frequency, onset temperature, pressure amplitude, acoustic power and efficiency. The conclusions derived from the analysis are reported in the paper.