热端温度对热声发动机性能影响的数值研究

Numerical research on effect of hot end temperature on thermoacoustic engine performance

建立场协同模型,采用计算流体动力学(CFD)方法,对1/4波长驻波热声发动机进行二维数值模拟研究,分析不同热端温度下系统内声功率的变化情况以及板叠与气体工质间的对流传热特性。研究结果表明:波动压力与体积流率幅值随着热端温度的升高而不断增大,相位差随着热端温度的升高呈下降趋势,特定结构的热声发动机对应使系统声功输出最大的最佳热端温度;随着热端温度的升高,板叠与气体工质间的换热量也不断增大,且发现声功率并不与热流量成正比,板叠存在着固定吸热与放热区域。

The synergy model was established and the computational fluid dynamics (CFD) method was used to conduct the two-dimensional numerical simulation on the 1/4 wavelength standing wave thermoacoustic engine. The changes of sound power within the system under different hot end temperatures and convective heat transfer characteristics between the stacks and the working gas were analyzed. The results show that fluctuations of pressure and amplitude of volume flow rate increase with the increase of the hot side temperature, that phase has a downward trend with the increase of the hot end temperature, and that the thermoacoustic engine with specific structure corresponds to the optimum temperature of the hot end allowing acoustic power output of the system to reach the maximum. Heat transfer between stacks and the working gas also increases with the increase of the hot end temperature, and sound power is not proportional to the size of the heat flow. There is a fixed endothermic and exothermic region in the stacks.