Numerical investigation of dual thermoacoustic engine

The thermoacoustic phenomenon describes the interactions between acoustic waves and heat flow. Due to the course of the phenomenon, we can distinguish refrigerators that use acoustic waves to create a temperature gradient and engines in which a temperature gradient generates acoustic waves. From the perspective of acoustics, we can distinguish devices using a standing wave and a traveling wave. One of the potential structural solutions of a thermoacoustic standing wave engine is a double engine. It is a solution that combines the cold ends of two identical thermoacoustic engines through a movable piston, to increase the stability of work and to facilitate the conversion of acoustic waves into mechanical or electrical energy. The paper attempts to numerically analyze a dual thermoacoustic engine. The calculations were performed in the Ansys Fluent environment. The method of introducing to the numerical model the UDF function describing the movement of the piston with respect to inertia and the influence on the possibility of automatic remeshing of the two-dimensional model is discussed. The results of the analysis of the start-up process and the work of the dual engine are presented. The inertia effect of the piston on the course of starting and operation of the engine was checked by comparing several cases of piston mass. The obtained results were compared with the numerical solution for a single engine with identical geometry.