作　　者： ; ; ; ;

机构地区： 南京理工大学动力工程学院瞬态物理国家重点实验室

出　　处： 《应用力学学报》 2013年第2期190-195,301,共6页

摘　　要： 为了详细揭示低对流马赫数下平面混合层的声波产生机理,基于高精度混合格式,对空间发展的平面混合层的流场结构及其声场特性进行了直接模拟。数值结果描述了对流马赫数为0.4时混合层失稳产生的涡串以及涡发展过程中所存在的各种声源,其中包括常规的单涡四极子声源、双涡以及多涡合并过程产生的四极子声源,另外,还发现因K-H不稳定引起混合层振动而产生的偶极子声源,声波以平面波的形式向周围传播。 To reveal the generating mechanism of the acoustic sources in a low convection Mach number planar mixing layer,in this paper,based on the high-order hybrid scheme,the spacial developed,planar mixing layer and its acoustic near field have been simulated.Our numerical results expose the phenomena of vortexlets generated by the instability of mixing layer in convection Mach number at Mc=0.4,vortex pairing,and the coalescing of three and multiple of vortexes during their development.Moreover,the different characteristics of acoustic sources of the low convection Mach number mixing layer are also obtained,they include the common quadrupole source induced by the vortex rolled up,vortex pairing and the coalescing of three and multiple vortices.Moreover,we find that the dipole source caused by the vibration of mixing layer for K-H instability,and its acoustic wave radiates around as the plane waves.

关 键 词： 混合层 气动声学 涡合并 声源

领　　域： [理学] [理学]