Visualization of coherent structures in a supersonic flat-plate boundary layer  

作　　者：HE Lin YI ShiHe ZHAO YuXin TIAN LiFeng CHEN Zhi 

机构地区：[1]College of Aerospace and Material Engineering, National University of Defense Technology, Changsha 410073, China

出　　处：《Chinese Science Bulletin》2011年第6期489-494,共6页

基　　金：supported by the National Basic Research Program of China (2009CB724100)

摘　　要：Flow in a flat-plate zero-pressure-gradient boundary layer at Mach 3 was visualized via nanoparticle-based planar laser scattering (NPLS). Coherent structures such as an individual hairpin vortex and hairpin packet were identified in the streamwise-wall-normal plane on the basis of the now accepted hairpin model. Λ-shaped vortices were found in a staggered pattern in the stream-wise-spanwise plane, which indicated H-type transition in the present experiments. This is the direct evidence (in the form of flow visualization) of such coherent structures in a supersonic boundary layer. A series of NPLS images taken in streamwise-spanwise planes at different heights is presented, and the three-dimensional structures of the supersonic boundary layer agree well with the hairpin model.Flow in a flat-plate zero-pressure-gradient boundary layer at Mach 3 was visualized via nanoparticle-based planar laser scattering （NPLS）. Coherent structures such as an individual hairpin vortex and hairpin packet were identified in the streamwise-wall- normal plane on the basis of the now accepted hairpin model. A-shaped vortices were found in a staggered pattern in the stream- wise-spanwise plane, which indicated H-type transition in the present experiments. This is the direct evidence （in the form of flow visualization） of such coherent structures in a supersonic boundary layer. A series of NPLS images taken in streamwise-spanwise planes at different heights is presented, and the three-dimensional structures of the supersonic boundary layer agree well with the hairpin model.

关 键 词：超音速边界层 相干结构 可视化 平板 菲亚特 三维结构模型 NPLS 激光散射 

分 类 号：O357.41[理学—流体力学] O357.5[理学—力学]