Interaction of pulsed laser energy with bow shock in Mach 5 flow

Abstract

Pressure sensing and schlieren imaging with high resolution and sensitivity were applied to the study of the interaction of pulsed laser energy with bow shock at Mach 5. A Nd:YAG laser operated at 1.06μm, 100mJ pulse energy was used to breakdown the hypersonic flow in shock tunnel. 3 dimensional Navier-Stokes equations were solved with upwind format to simulate the interaction. Stagnation pressure of the blunt body was measured and calculated to examine the pressure variations during the interaction. Schlieren imaging was used in conjunction with the calculated density gradients to examine the process of the interaction. Results showed that the experimental stagnation pressure and schlieren imaging fitted well with the simulation. Stagnation pressure would increase when the transmission shock approached to the blunt body and decrease with the reflection of the transmission shock. Bow shock was deformed during the interaction. Schlieren imaging supplied important phenomenon to investigate mechanism of the interaction.