Visual Study on Mach Reflection of Shock Waves Propagating through a Fog

Abstract

Mach reflection of shock waves propagating through a fog was investigated experimentally with a shock tube. A fog was generated by the adiabatic expansion of the water vapor and air mixture by using a double diaphragm type shock tube. Mach reflection from an inclined flat surface was observed by means of shadowgraph method. As a light source, a nano pulse light was used. Shadowgraphs of Mach reflection have been obtained when an inclination angle of the flat surface was 20 degrees and the initial relative humidity of a mixture was changed from 50% to 90%. Experimental results shows that the incident shock wave was dispersed by the mist and the relaxation region was formed behind the shock front.