Investigation of Edney IV shock wave interaction based on color schlieren

To investigate the Edney Ⅳ shock wave interaction in hypersonic flow,color schlieren with high resolution and sensitivity was developed.Knife edge in traditional schlieren system was replaced by a special designed color filter in this system.High speed color camera with 60μs exposure time and 6242fps was used.To improve the sensitivity of the system,the light source was restricted by a rectangular slot with 0.5mm×20mm.The experiment was performed in shock tunnel at Mach 5.Edney Ⅳ interaction was generated in hypersonic free stream by 15° edge and blunt body with diameter of 20mm.The static pressure and temperature of the flow were 1800Pa and 100K,respectively.Three dimensional RANS equations were solved with upwind format to simulate the interaction.Clear color schlieren photo was gotten,which detailedly exhibited the wave system structure of Edney Ⅳ interaction and the supersonic jet at Mach 1.2.The simulation results matched well with the experiment,revealing the mechanism of Edney Ⅳ shock wave reaction and the formation of the high pressure region on the blunt body.