Numerical Studies of Laser-Induced Energy Deposition for Supersonic Flow Control

Abstract

This work deals with the computational study of localized laser energy deposition in supersonic flows. A model for Nd:YAG laser energy deposition in air has been developed for this purpose. It is designed to predict the fluid dynamic effects of the energy deposition process in supersonic flows. The key physical processes are captured, including inverse bremsstrahlung absorption, evolution of the plasma shape and structure, air breakdown chemistry, and the subsequent fluid dynamics. The model is validated using measurements of experiments done in quiescent air. The effects of energy deposition in three-dimensional supersonic flow past sphere and a flow with Edney type IV shock-shock interaction were studied. The energy deposition was found to be effective in reducing the peak surface pressure, but not as effective in lowering the surface heat-transfer rate. In the case of flow with Edney type IV shock-shock interaction, a study was performed to find the optimal location for the energy deposition, for which there is maximum decrease in the surface pressure.