Effects of Different Flow Field Conditions on the High Power Transmission Properties of a Reentry Plasma

Abstract

A computer program for calculating the high power microwave transmission coefficients of a chemically seeded reentry plasma has been described in two previous reports. It has been explained how the computer code can be used to optimize the amount of high power that can be transmitted from a reentry vehicle. Using a half implicit – half explicit time integration scheme, the electron and ion transport equations coupled with Maxwell's equations are numerically integrated to determine the nonlinear reflection and transmission coefficients of a reentry plasma. Graphs are presented of the electron density profile and plane wave reflection and transmission coefficients corresponding to the flow field conditions of a blunt-nosed reentry vehicle. The nonlinear transmission effects are studied as a function of vehicle altitude, antenna location on the vehicle, incident power level, pulse length, pulse repetition frequency, and convective flow velocity. Good agreement is obtained between theoretical results and actual rocket flight data.