关键词: 脉冲爆震发动机;爆炸力学;流场可视化;悬吊激波;数值仿真

Abstract: The external flow field was visualized using the experimental and numerical method.The YA-16 high speed shadowgraph system was adopted in test to obtain the consequential clear shadowgraphs of the external flow field.Moreover,by solving axisymmetric Navier-Stokes equations in conjunction with the chemistry,a numerical simulation of pulse detonation process induced by flame in the tube with H2-O2-N2 mixture and the distribution of the internal and external flow field was performed,and a detailed chemical mechanism of H2-O2-N2 system,which included 19 element reactions and 9 species,was involved.Based on the numerical results,the computational shadowgraphs were obtained through computational flow images.Comparisons of the computational shadowgraphs with the experimental shadowgraphs show good agreement in trend.Both the experimental and the computational shadowgraphs visually demonstrate the development of the external flow field.Based on the experimental and numerical results,the dynamics mechanism of the occurrence and development of the vortex ring and the suspended shock is elucidated systematically.

Key words: Pulse detonation engine;Mechanics of explosion;Flow field visualization;Suspended shock;Numerical simulation