用于气动声学计算的完全耦合层吸收边界条件

中国机械工程 ›› 2014, Vol. 25 ›› Issue (17): 2356-2360.

用于气动声学计算的完全耦合层吸收边界条件

陈志夫1;文桂林1;卿宏军2;王明1;王艳广1

1.汽车车身先进设计制造国家重点实验室，长沙，410082
2.湖南大学，长沙，410082

出版日期:2014-09-10 发布日期:2014-09-22
基金资助:
国家杰出青年科学基金资助项目(11225212)；国家自然科学基金资助项目(11002052，11072074)；国家科技支撑计划资助项目(2012BAH09B02)；湖南省自然科学创新研究群体基金资助项目(12JJ7001)；湖南大学汽车车身先进设计制造国家重点实验室开放基金资助项目(31275006)

PML Absorbing Boundary Conditions for Computational Aeroacoustics

Chen Zhifu1;Wen Guilin1;Qing Hongjun2;Wang Ming1;Wang Yanguang1

1.State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Changsha,410082
2.Hunan University,Changsha,410082

Online:2014-09-10 Published:2014-09-22
Supported by:
National Science Funds for Distinguished Young Scholars( No. 11225212);National Natural Science Foundation of China（No. 11002052，11072074）;The National Key Technology R&D Program（No. 2012BAH09B02）

摘要/Abstract

摘要：

根据伪时均流假设，推导了波动量的非守恒非线性欧拉方程;采用频率变化的方法，给出了一个时间与空间坐标变换关系，并将波动量的非守恒非线性欧拉方程变换至新坐标系;通过复数变换方法引入阻尼，构建了斜流非守恒非线性x层、y层及角层完全耦合层(PML)吸收边界条件;最后用算例测试了该吸收边界条件的精度和收敛性。研究结果表明：当吸收层数等于10时，最大反射量不超过0.5%，并且随着PML层数的增加而迅速减小;当吸收层数为40层时，最大反射量小于0.1%，达到收敛;在背景斜流下，该PML吸收边界条件能较好地吸收熵波与声波，可用于气动声学计算。

关键词: 欧拉方程, 计算气动声学, 完全耦合层, 边界条件

Abstract:

For nonlinear Euler equations in primitive variables，a pseudo mean flow was introduced in the derivation of the time-dependent fluctuation equations. Then a hypothesis for changed frequency was employed, a proper space-time transformation was presented for deriving the time-dependent fluctuation equations in transformed coordinates. A complex change was applied to the new equations and a damping parameter was introduced. Several nonlinear PML absorbing boundary condition in primitive variables for x layer, y layer and corner layer were derived. Finally, the stability and effectiveness of nonlinear PML absorbing boundary conditions were validated by computing the CAA benchmark problems. The results prove that: the maximum reflection error is less than 0.5% and 0.1% with PML width of 10 and 40 layers grid points, respectively, and the reflection error reduces with the increase of PML width; for actual CAA problems in the case of oblique mean flow, the proposed PML absorbing boundary conditions can absorb the vortex and acoustic wave with little or no reflection.

Key words: Euler equation, computational aeroacoustics(CAA), perfectly matched layer(PML), boundary condition

中图分类号:

V211.3

陈志夫, 文桂林, 卿宏军, 王明, 王艳广. 用于气动声学计算的完全耦合层吸收边界条件[J]. 中国机械工程, 2014, 25(17): 2356-2360.

Chen Zhifu, Wen Guilin, Qing Hongjun, Wang Ming, Wang Yanguang. PML Absorbing Boundary Conditions for Computational Aeroacoustics[J]. China Mechanical Engineering, 2014, 25(17): 2356-2360.

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