基于关联速度的FW-H积分四极子声源修正模型  

Quadrupole source term corrections based on correlation functions for Ffowcs Williams and Hawkings integrals

作　　者：周志腾 王洪平 王士召 何国威[1,2] ZHOU Zhiteng;WANG Hongping;WANG Shizhao;HE Guowei(Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院力学研究所非线性力学国家重点实验室,北京100190 [2]中国科学院大学工程科学学院,北京100049

出　　处：《空气动力学学报》2020年第6期1129-1135,I0003,共8页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(11988102);国家数值风洞工程;国家自然科学基金(91752118,91952301)。

摘　　要：FW-H积分中的四极子声源项常在远场噪声的计算中引起虚假声源问题。这类虚假声源是由于计算四极子声源的积分域不能包含全部声源区域,Lighthill应力张量穿过四极子声源的积分域边界引起的。本文在频域方法的框架下改进了四极子声源项的修正模型,用于修正Lighthill应力张量穿过积分域边界引起的误差。该模型基于泰勒冻结流假设,利用关联函数计算Lighthill应力张量的对流速度。与常用的均匀来流对流速度相比,本文提出的模型考虑了对流速度的空间非均匀性,改善了非均匀流动区域FW-H积分面对远场噪声的影响。二维对流涡和圆柱绕流的远场噪声验证了本文模型的有效性。The quadrupole source term in the Ffowcs Williams and Hawkings(FW-H)integrals usually causes spurious contributions to the far field sound.The spurious contributions are contributed by the convection of the Lighthill stress tensor crossing the FW-H integral surface when the integral domain cannot include all the quadrupole sources.We proposed a quadrupole source term correction model within the frequency domain to correct the errors associated with the convection of Lighthill stress tensor.Based on Taylor’s hypothesis,the proposed model uses the correlation functions of the Lighthill stress tensor to compute the convection velocity.Compared with the using of uniform upstream velocity as the convection velocity,the proposed model has the advantages of taking account for the non-uniform distribution of the convection velocity.We validate the proposed model by computing the far-field sound generated by the two-dimensional convecting vortex and the flows around a circular cylinder.The proposed model significantly improves the directivity of the far field sound generated by the flows around the circular cylinder.

关 键 词：流动噪声 FW-H积分 四极子声源 泰勒冻结流假设 关联速度 Lighthill应力张量 气动声学 

分 类 号：O242[理学—计算数学]