A Thermoacoustic Engine with Gas and Liquid Operating Below 10 Hz

Abstract

A thermoacoustic engine operating below 10 Hz, with gas and liquid as the working fluids, is experimentally studied in this paper. The emphasis of measurement and analysis focuses on the impact of liquid column mass, mean operating pressure, gas working fluids, and liquid working fluids on the resonant frequency and the pressure amplitude. Experimental results demonstrate that a remarkable drop of resonant frequency and an increase of pressure amplitude can be realized by introducing a liquid column into a thermoacoustic engine with mere gas working fluid. A larger liquid column mass or a higher mean operating pressure can lead to a higher pressure amplitude. Compared with nitrogen, carbon dioxide and helium, argon seems to be advantageous for achieving a larger pressure amplitude at the same heating power, whereas the carbon dioxide-water system gets the lowest resonant frequency. As to the liquid working fluid, a small viscosity is preferable for elevating the pressure amplitude.