气动声学计算中一种声扰动方程的改进

研究了气动声学计算中的一种改进声扰动方程(IAPE)。采用三种不同的声传播模型,数值分析了声在均匀流以及剪切流中的传播问题。与线化欧拉方程(LEE)相比,除了个别位置预测的压力峰值较小以外,声扰动方程(APE)几乎能够预测到类似的物理特性;另外,APE方程具有无需求解密度方程,计算成本相对较少等优点。为弥补APE方程预测压力峰值较小的缺点,通过分析APE方程,这类方程中需要加入剪切流与声波相互作用的源项。为此,对APE方程进行改进,加入了一种声源项,计算结果表明,改进的APE方程(IAPE)能够和线化欧拉方程的计算结果保持一致。

An Improved Acoustic Perturbation Equation for Computational Aeroacoustics

An improved acoustic perturbation equation in computational aeroacoustics is studied in the paper.Acoustic propagation in a shear mean flow is studied numerically using different acoustic propagating models.From the numerical point of view,Acoustic Perturbation equations（APE） model can predict almost the same physical behaviors but the predicted pressure peaks have smaller amplitudes depending on the locations,as compared to Linearized Euler equations（LEE）.On the other hand,APE solves one equation less and thus is computationally less expensive.Looking more closely the formulation of APE,a source term which represents the interaction from mean flow to acoustic waves is missing.To overcome the drawback of APE,an improved APE（IAPE） is proposed for APE with a source term derived from LEE.The calculated results from IAPE show excellent agreements with LEE in the cases of shear mean flows.