Study on Working Fluids Testing and Multiphase Flow Model Optimization in Thermoacoustic Engines

Key Laboratory of Low-Grade Energy Utilization Technology and System of Ministry of Education, Chongqing University, Chongqing 400044, China

^* Corresponding author: 202210131120@stu.cqu.edu.cn

Abstract

This study investigates the impact of different working fluids on the performance of non-phasechange thermoacoustic engines and compares the application of two multiphase flow models in phasechange thermoacoustic engines. Simulation results show that, at the same heating temperature, air and nitrogen can achieve thermoacoustic oscillations, while helium cannot. This is due to helium’s higher sound speed, lower density, and higher thermal conductivity et al. In the simulation of phase-change thermoacoustic engines, the Mixture model demonstrates higher predictive accuracy compared to the VOF model, as the VOF model emphasizes the effects of phase interfaces, while the Mixture model is better suited for macro-scale multiphase flow analysis and relatively uniform phase-change processes. The findings provide a theoretical basis for the optimization design of phase-change thermoacoustic engines.