热声斯特林发动机热动力学特性的CFD研究——第一部分:热声自激振荡演化过程

采用商业计算流体动力学(CFD)软件Fluent6.0对热声斯特林发动机热动力学特性进行了热声自激振荡演化过程的数值模拟研究.主要研究了边界条件、初始条件和数值离散方法对模拟瞬态、可压缩、非线性的热声系统的重要影响,同时给出了两种在回热器内部建立温度梯度的方法,比较了它们对应的不同自激振荡演化过程.模拟结果表明,在高于功产生的临界温度梯度时,波动压力振幅被显著放大.本研究初步验证了该CFD研究的有效性.

Thermodynamic and dynamic performance study of thermoacoustic-Stirling heat engines by using CFD Part Ⅰ: Evolution process of self-excited thermoacoustic oscillation

The evolution process of self-excited thermoacoustic oscillation,which is the thermodynamic and dynamic performance of a thermoacoustic-Stirling heat engine,was studied by using the computational fluid dynamics(CFD) software Fluent6.0.The work was mainly about the influences of boundary conditions,initial conditions and numeric methodology on the simulation of transient,compressible and nonlinear process.Meanwhile,two methods of building up of the temperature gradient in the regenerator were given and the comparison of the evolution process of corresponding different spontaneous oscillations was made.The simulation result shows that the dynamic pressure amplitude was amplified obviously when the temperature gradient was above the critical value.This study verified the validity of CFD method.