高亚声速湍流喷流气动噪声数值分析  

NUMERICAL INVESTIGATION OF NOISE OF A HIGH SUBSONIC TURBULENT JET

作　　者：冯峰[1] 郭力[1] 王强[1] Feng Feng Guo Li Wang Qiang(China Academy of Aerospaee Aerodynamics, Beijing 100074, China)

机构地区：[1]中国航天空气动力技术研究院,北京100074

出　　处：《力学学报》2016年第5期1049-1060,共12页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(11302215;11102198);国家"973"计划(2014CB744100)资助项目

摘　　要：为适应航空噪声管制规定要求,发动机喷流噪声控制成为目前气动声学研究中的重要课题,预测分析喷流噪声辐射并揭示其产生机理将为噪声控制奠定基础.采用高精度并行LES(large eddy simulation)方法计算分析马赫数0.9高亚声速喷流的湍流演化和气动噪声现象.首先,仔细验证喷流LES湍流场计算保真性,并分析流场中不同尺度涡结构的演化形态.其次,利用可穿透面FW-H(Ffowcs Williams and Hawkings)方法外推喷流近场声源数据获得精确声辐射远场,进而分析声场主导声模态特性.最后,通过分析声源机制、分离声模态等方法研究势流核末端大尺度拟序涡运动演化形成的低波数波包在噪声主导声模态产生中的重要作用.数值结果表明LES结合可穿透面FW-H方法可精确预测高亚声速喷流的流场及声场特征,且数值分析揭示涡环对并形成的大尺度拟序结构在喷流中心线上沿径向融合,产生了在远场低方位角占优的主导声模态,并构成强指向性声场,噪声峰值方位角约为30?.To meet the regulations of aviation noise, noise control of jet engine has grown to become a major issue in aeroacoustics, therefore prediction of jet noise and unfolding its generation mechanism would lay a solid foundation for the noise control. Turbulence evolution and noise of a Mach 0.9 high subsonic jet are investigated by high-order accurate parallel LES（large eddy simulation）. Firstly, the fidelity of turbulence result computed by LES is rigorously verified,and the evolution of multi-scale vortex structures is carefully analyzed. Secondly, based on the acoustic source in near field of the jet, the penetrable FW-H（Ffowcs Williams and Hawkings） wave extrapolation method is used to solve the farfield acoustic and analyze the behavior of the dominant modes. Finally, via analyzing mechanism of acoustic source and separating the acoustic modes, the role of the large-scale coherent vortex evolution in the end of potential core play in dominant acoustic modes generation as a form of low wave number wavepackets is investigated. Numerical results show that LES combined with the penetrable FW-H method is able to accurately predict the flow and acoustic features of the high subsonic jet. Furthermore, numerical analysis reveals that the large-scale coherent structure generated by the vortex ring pairing is merging along the jet centerline, which producing the primary acoustic modes dominated at the low azimuth direction and forming a superdirective acoustic field. The azimuth angle of the peak intensity is near to 30？.

关 键 词：高亚声速喷流 声辐射 波包 FW-H方法 大涡模拟 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]