基于声源视角法的气动噪声计算研究

The Study of Aeroacoustic Computing Efficiency Based on Acoustic Analogy

为提高气动噪声求解效率,Casalino提出了声源视角法,首先详细阐述了该方法,并列举其相比传统延迟时间法的优越之处。该方法主要是从声源视角重新建立延迟时间方程,此时无论声源运动形式是否复杂,都使延迟时间方程从超越方程变为代数方程,无需迭代即可直接求解,提高了声场程序的求解效率。其次新建立的延迟时间方程给求解声场的程序设计也带来很大便利,即无需预先存储大量时间步的流场数据,流场求解和声场求解在程序中可以同时进行。并且当接收点无论是静止、亚声速运动还是超声速运动,新建立的延迟时间方程的解均能给出明确的物理意义。最后以声源视角法为基础,通过编写声场求解程序并结合已有的流场求解程序求解圆柱绕流和后视镜绕流2个算例,进一步检验声源视角法的准确性和有效性,计算结果与实验结果吻合良好,表明了声源视角法准确、有效。

In order to improve the computing efficiency of aeroacoustic, the retarded time equation is reconstructed based on the Casalino＆#39;s advanced time approach from view of source domain. The retarded time equation was trans-formed regardless of the way of source moving form transcendental equation to algebraic equation. So the computing efficiency was improved by avoiding iterative methods. What′s more, there is a convenience produced by the new retarded time equation that no fluid data is necessary to prestore and acoustic is computed at the same time. In addi-tion, whether observer position with static, subsonic or supersonic, the solution of new retarded time equation has clear physical significance. finally, the efficiency of new approach was proved using a example of flow over cylinder and a example of flow over car mirror.