Tomographic particle image velocimetry measurements of synthetic jet in turbulent boundary layer  

作　　者：Jin-hao Zhang Li-juan Shi Xing-yu Ma Zhan-qi Tang Xiao-qi Cheng Nan Jiang 

机构地区：[1]Department of Mechanics,School of Mechanical Engineering,Tianjin University,Tianjin,300350,China [2]Key Laboratory of Modern Engineering Mechanics,Tianjin University,Tianjin,300350,China

出　　处：《Journal of Hydrodynamics》2024年第5期854-869,共16页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12332017,12272265,12172242,12202310,12202309 and 12372278).

摘　　要：We experimentally investigate the 3-D flow characteristics caused by synthetic jet in the turbulent boundary layer(TBL),with the aim of analyzing the differences and similarities of hairpin vortices generated by jet of different hole diameters.For flow fields with hole diameters of 3 mm,4 mm,5 mm,the 2D time-resolved particle image velocimetry(TR-PIV)is used for preliminary experiment to determine the generation region of these hairpin vortices,and then the three-dimensional instantaneous snapshots of the region are obtained by tomographic PIV(Tomo-PIV).The statistical average results show that the downstream velocity deficit area is positively correlated with the hole diameter,and the drag reduction effect looks better with small hole diameter.The phase average extracts the three-dimensional morphology of the hairpin vortices produced by synthetic jet,and its distribution tends to be dense with the hole diameter,which is related to the velocity deficit.The two-point cross-correlation coefficient represents the scale of the coherent structure,and the three component scales of these hairpin vortices are smaller with large hole diameter,which is due to insufficient space for development.The flow fields are divided into high-energy and low-energy by proper orthogonal decomposition(POD).It is found that the increase of hole diameter can transfer the generated hairpin vortices from low-energy to high-energy,showing that the strength of high-energy hairpin vortices is positively correlated with the hole diameter.

关 键 词：Turbulent boundary layer synthetic jet hairpin vortex tomographic particle image velocimetry(Tomo-PIV) 

分 类 号：O35[理学—流体力学]