The Effect of Micro-ramps on Supersonic Flow over a Forward-Facing Step  

作　　者：ZHANG Qing-Hu YI Shi-He ZHU Yang-Zhu CHEN Zhi WU Yu 张庆虎;易仕和;朱杨柱;陈植;武宇(College of Aerospace Science and Technology,National University of Defense Technology,Changsha 410073)

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

出　　处：《Chinese Physics Letters》2013年第4期119-121,共3页中国物理快报（英文版）

基　　金：the National Natural Science Foundation of China under Grant No 11172326;the National Basic Research Program of China under Grant No 2009CB724100;the Scientific Research Program of National University of Defense Technology under Grant No 0100010112001.

摘　　要：The effect of micro-ramp control on fully developed turbulent flow over a forward-facing step(FFS)is investigated in a supersonic low-noise wind tunnel at Mach number 3 using nano-tracer planar laser scattering(NPLS)and supersonic particle image velocimetry(PIV)techniques.High spatiotemporal resolution images and the average velocity profiles of supersonic flow over the FFS with and without the control of the micro-ramps are captured.The fine structures of both cases,including the coherent structures of fully developed boundary layer and the large-scale hairpin-like vortices originated from the micro-ramps as well as the interaction of shock waves with the large-scale structures,are revealed and compared.Based on the time-correlation images,the temporal and spatial evolutionary characteristics of the coherent structures are investigated.It is beneficial to understand the dynamic mechanisms of the separated flow and the control mechanisms of the micro-ramps.The size of the separation region is determined by the NPLS and PIV.The results indicate that the control of the micro-ramps is capable of delaying the separation and diminishing the extent of recirculation zone.

关 键 词：separation COHERENT TURBULENT 

分 类 号：O35[理学—流体力学]