Modification of Flow Structure and Sound Source by Hybrid Porous-serrated Trailing Edge  

作　　者：Hanru Liu Nanshu Chen Yangang Wang Zhijie Hu 

机构地区：[1]School of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China [2]Research&Development Institute of Northwestern Polytechnical University in Shenzhen,Shenzhen 518057,China [3]Key Laboratory of Aerodynamic Noise Control,Mianyang 621000,China

出　　处：《Journal of Bionic Engineering》2020年第3期539-552,共14页仿生工程学报（英文版）

基　　金：The authors would like to acknowledge the financial supported by the National Natural Science Foundation of China(No.11772146);Science,Technology and Innovation Commission of Shenzhen Municipality(No.JCYJ20170817110605193);Natural Science Foundation of Shaanxi Province(No.2018JM5067);Foundation of Key Laboratory of Aerodynamic Noise Control(No.ANCL20180105).

摘　　要：The effects of hybrid porous-serrated trailing edge on flow structure and sound source of NACA65(12)-10 at moderate Reynolds number(Rec=5×1O^5)have been investigated by Delayed Detached Eddy Simulation(DDES).Compared with conventional serrated trailing edge,the pressure fluctuation in the vicinity of hybrid porous-serrated trailing edge is further decreased significantly.The typical necklace vortex structures stretching across adjacent serrations are suppressed by the porous additive.It is found that porous media changes the shear stress distribution along the serration edge and inside the serration gap,which consequently eliminates the generation of necklace vortex.Therefore,the deformation of vortex tube caused by velocity vector is weakened.The underlying mechanisms associated to the sound source modification are analyzed based on vortex sound theory.The magnitude of Lamb vector and the angle between vorticity and velocity vectors are synchronously reduced by the porous additive,which implies that the present hybrid porous-serrated trailing edge has important influence on the further attenuation of far-field aerodynamic noise.

关 键 词：bionic flow control wake modification hybrid porous-serration vortex sound theory noise reduction 

分 类 号：O35[理学—流体力学]