热声发动机的CFD数值模拟

NUMERICAL SIMULATION OF THERMOACOUSTIC HEAT ENGINES

采用计算流体动力学(CFD)方法,对高频驻波热声发动机和热声斯特林发动机实验系统分别进行了二维和三维数值模拟。计算模型具有与实验系统相同的几何结构、尺寸和运行工况。对计算模型的有效性进行了研究,表明实现有限换热条件的板叠实物模型适合驻波热声发动机的模拟,而实现局域热平衡的多孔介质模型适合热声斯特林发动机的模拟。计算结果成功观测到了非线性的自激振荡演化过程,捕捉到了两种发动机的不同非线性现象。计算结果分别给出了两种热声发动机内部的声场分布特性和复杂流场。计算结果与实验结果的对比验证了CFD方法对高频驻波热声发动机和热声斯特林发动机模拟的有效性。

An experimental high-frequency standing-wave thermoacoustic heat engine and thermoacoustic-Stirling heat engine are simulated by using computational fluid dynamics（CFD）.The numerical models have almost the same geometrical configurations,dimensions and operating conditions as those in the experimental systems.The models are validated and indicated that the solid and fluid coupled model that assumes finite heat transfer is feasible for the simulation of the standing-wave thermoacoustic heat engine,while the porous model that assumes local thermal equilibrium is suitable for the simulation of the thermoacoustic-Stirling heat engine.The calculations successfully captured the nonlinear spontaneous oscillation,and observed different nonlinear phenomenon in the engines. Meanwhile,the complicated acoustic field and flow field are given.Finally,the calculated results are validated with the experimental results.