在计算气动声学中用非线性滤波法消除短波  

Elimination of Short Waves in Computational Aeroacoustics Using a Nonlinear Filter

作　　者：王泽晖[1] 罗柏华[2] 刘宇陆[1] 

机构地区：[1]上海大学上海市应用数学和力学研究所 [2]上海大学理学院,上海200436

出　　处：《上海大学学报（自然科学版）》2004年第4期393-399,共7页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目 (1 0 2 72 0 71 )

摘　　要：在计算气动声学中,发展能抑制短波而对长波没有影响的方法是一个值得关注的问题.该文探讨了Bj rnEngquist等人提出的非线性滤波法在计算气动声学中的应用.根据一个检验函数,分析了非线性滤波效率与波长的关系;引入了具有TVD性质的非线性滤波法;通过数值算例,说明了保色散关系(DRP)格式与非线性滤波法结合的可行性,表明该方法对于在网格交界面、初始值间断、非线性声波传播等计算气动声学常见情况下产生的短波有很好的抑制作用.In computational aeroacoustics (CAA), it is important to develop procedures that are (effective) in eliminating short waves without affecting long waves. The idea of using a nonlinear filter proposed by Bjrn Engquist in computational aeroacoustics is investigated. The relationship between the filtering effect and the wavelength is studied through a test function. In order to eliminate the (oscillations) around shock, a method of TVD nonlinear filtering is introduced in CAA. Through nu-merical tests, it is shown that the nonlinear filter is effective in combining with dispersive-relation-(preserving) (DRP) scheme to suppress numerical short waves of wavelengths 2Δx and 4Δx, excited at (numerical) interfaces (changes of grid size, initial discontinuity, or shocks) and propagated due to numerical computation. The results show that the method is applicable to CAA.

关 键 词：保色散关系(DRP)格式 短波 寄生波 非线性滤波法 TVD 

分 类 号：O355[理学—流体力学] O422[理学—力学]