摘要
为避免气动噪声数值模拟中流场高精度计算所带来的巨大工作量,同时考察非紧致边界的散射效应,采用二阶精度格式进行可压缩流场计算,将流场脉动量分解为流场数值计算捕获的主要由流体运动引起的流动脉动分量和流场计算未捕获的主要由噪声传播引起的声学脉动分量两部分,基于Lighthill声模拟理论和格林函数波动方程,导出气动噪声辐射散射统一积分计算方法。首先将观察点布置在物体表面,通过统一积分方程计算得到非紧致物面边界上的散射声压,然后将观测点移到远场位置计算得到声场区域内任意观察点的声压。对二维、三维圆柱以及二维翼型开展气动噪声数值计算,结果与文献计算以及实验结果相吻合,表明本文提出的这种统一积分计算方法能够减少流场高精度计算所需的工作量,同时还能够准确地模拟非紧致结构对气动噪声的散射效应。
In order to deal with the high requirement for computation resources of a high order method in the aeroacoustic nu- merical simulation, and also take into consideration the scattering effects from noncompact bodies, a unified aeroacoustic computational method of noise radiation and scattering is presented in this paper which combines the calculation of the scat- tering noise due to noncompact surfaces and the radiation noise induced by flow field variables. The pulsations of the flow field variables are divided into hydrodynamic components and acoustic components, and then an integral solution for scatter- ing scattering noise and far field noise is obtained based on Lighthill acoustic analogy theory and the wave equation of Green＇s function. According to this method, numerical calculation is developed in two steps. The scattering pressure distri- bution is first obtained by solving the unified integral equation with the observation points located on the body surface, and then the far field pressure of arbitrary points is computed when the observation point is located in the far field. Verification work is developed in connection with the numerical calculation of two-dimensional and three-dimensional circular cylinders and a two-dimensional NACA0012 airfoil. The calculated aeroacoustic results agree well with experimental data and the nu- merical results of other methods. This shows compact bodies accurately while significantly that this unified integral method is able to calculate the scattering effect of non- reducing the computation load.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2013年第11期2482-2491,共10页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(11002116)
西北工业大学基础研究基金(GCKY1006)
关键词
气动噪声
辐射
散射
可压缩性
非紧致结构
积分方程
aeroacoustics
radiation
scattering
compressibility
noncompact body
integral equation
