Numerical analysis on thermoacoustic prime mover

A two-dimensional numerical model based on compressible SIMPLE algorithm was developed to simulate the evolution process of self-excited oscillation in a thermoacoustic engine at two different heating conditions. Moreover, the performance analysis of the thermoacoustic engine was researched. On one hand, the influence of stack parameters and charge pressure on the onset temperature of self-excited thermoacoustic oscillation was exhibited and analyzed. On the other hand, the impact of different gas types on the onset temperature difference was investigated. The results indicated that the self-excited thermoacoustic oscillation happened with the same performance for both two heating conditions. The minimum onset temperature difference can be achieved when the dimensionless stack length and position are L_r = 0.055–0.06 and X_r = 0.14–0.16, respectively. For a detail, the optimal stack plate thickness is 33% of the stack channel width when the computational width is 3 times as large as the thermal penetration depth of the working gas. Furthermore, the onset temperature difference increased with the increasing of the charge pressure in prime mover. For different working gas, the onset temperature difference was the highest for argon, which was followed by helium and nitrogen. Finally, the performance was improved with the increase of the temperature difference between the two exchangers in the prime mover.