Oblique shock train motion based on schlieren image processing

作     者：Longsheng XUE Chuan CHENG Chengpeng WANG Lantian ZHANG Kang LI Keming CHENG Longsheng XUE;Chuan CHENG;Chengpeng WANG;Lantian ZHANG;Kang LI;Kemning CHENG

作者机构：College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Unsteady Aerodynamics and Flow ControlMinistry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Beijing Institute of Tracking and Telecommunication TechnologyBeijing 100094China Aerospace System Engineering ShanghaiShanghai 201109China 

出 版 物：《Chinese Journal of Aeronautics》 (中国航空学报（英文版）)

年 卷 期：2023年第36卷第3期

页      面：30-41页

核心收录：

学科分类：0711[理学-系统科学] 08[工学] 080103[工学-流体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Numerical Wind Tunnel Project of China,the National Natural Science Foundation of China(Nos.12002163 and 12072157) the Natural Science Foundation of Jiangsu Province,China(No.BK20200408) the China Postdoctoral Science Foundation(No.2022T150321) the Key Laboratory of Hypersonic Aerodynamic Force and Heat Technology,AVIC Aerodynamics Research Institute,China。 

主　　题：Frequency components Hysteresis loop Maximum Correlation Detection(MCD) Schlieren image processing Shock train oscillation 

摘      要：In this paper,shock train motion in a Mach number 2.7 duct is studied experimentally,and large numbers of schlieren images are obtained by a high-speed camera.An image processing method based on Maximum Correlation Detection(MCD)is proposed to detect shock train motion from the schlieren images,based on which the key structures,e.g.,separation positions and separation shock angles on the top and bottom walls,can be analysed in detail.The oscillations of the shock train are generated by rhombus and ellipse shafts at various excitation frequencies.According to the analysis of MCD results,the distributions of the frequency components of shock train oscillation generated by the two shafts are distinctly different,in which the motion generated by the ellipse shaft is much smoother;shock train motion is mainly characterized by the oscillation of separation position while the separation shock strength is not so sensitive to downstream disturbance;there is a hysteresis loop relation between the downstream pressure and separation position.