Simple Method for Predicting RF Attenuation Through a Rocket Exhaust Plume.

摘要

A simple method for predicting radio frequency signal attenuation through a rocket exhaust plume has been developed. A theoretical model development suitable for a writing a computer code to predict line-of-sight RF signal attenuation is presented. The model consists of seven calculation steps: 1. Nozzle exhaust conditions. 2. Correction for non-optimal nozzle expansion. 3. Plume inviscid core flow field. 4. Plume mixing/afterburning region flow field. 5. Plume electron and neutral body density field. 6. Electron-neutral body collision frequency. 7. Radio frequency transmission loss. The model uses many simplifying assumptions and represents the least complex approach available. The model is appropriate only for static-fired motors or low altitude, low Mach number flight profiles.