Standing Wave Thermoacoustic Refrigerator: The Principle of Thermally Driven Cooling

In their most basic forms, thermoacoustic devices are composed of a tube (resonator), a stack (porous medium) and two heat exchangers placed at the extremities of the stack. Work is created through the interaction of strong sound waves with the stack walls that is subject to external heating. The present work deals with a Computational Fluid Dynamics (CFD) simulation of standing wave thermoacoustic refrigerator composed of two stacks (driving and cooling stack) carried out using COMSOL Multiphysics. Through the interaction of thermally generated sound waves, cooling of the working gas near of the cold extremity of cooling stack is demonstrated. The results obtained are compared with those achieved using experiment. The study shows that the presence of the cooling stack affects the pressure amplitude achieved in the driving stack.