航空学报 > 2009, Vol. 30 Issue (3): 403-410

计算气动声学中的紧致滤波格式

柳占新,黄其柏,袁骥轩,胡溧   

  1. 华中科技大学 机械学院
  • 收稿日期:2007-12-18 修回日期:2009-01-12 出版日期:2009-03-25 发布日期:2009-03-25
  • 通讯作者: 柳占新

Compact Filtering Schemes for Computational Aeroacoustics

Liu Zhanxin, Huang Qibai, Yuan Jixuan, Hu Li   

  1. College of Mechanical Engineering, Huazhong University of Science and Technology
  • Received:2007-12-18 Revised:2009-01-12 Online:2009-03-25 Published:2009-03-25
  • Contact: Liu Zhanxin

摘要:

从理论上分析了数值伪波产生的原因,要消除数值伪波可用滤波方法。为了使滤波器具有理想的截断特性,引入了修正的高斯函数。通过让滤波器的频响函数与修正的高斯函数逼近,利用序列二次规划(SQP)方法优化了五对角紧致滤波格式。优化的滤波格式提高了计算精度和效率,增强了数值稳定性,更易于实施。一维和二维算例体现了优化滤波格式的性能改进。

关键词: 紧致格式, 滤波, 有限差分法, 序列二次规划, 计算气动声学

Abstract:

In this article spurious waves introduced in the computation of aeroacoustics are analyzed theoretically and filters are proposed to attenuate these waves as soon as they are generated. In order to obtain a sharp cutoff of the pentadiagonal filters, a modified Gaussian function is introduced. The transfer functions of the filters are forced to be approximated to the modified Gaussian function in a specific wavenumber domain. The sequential quadratic programming (SQP) method is employed to achieve the approximation. The accuracy, stability, and efficiency of computation are improved in the optimized filters, and they are more convenient for practical application. The improved performances of the optimized schemes are demonstrated through their application to one and two-dimensional problems.

Key words: compact scheme, filtering, finite difference method, sequential quadratic programming, computational aeroacoustics

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