Thermal radiation from the exhaust plume of an aluminized composite propellant rocket

Abstract

Abstract : A technique is developed for calculating rocket base heating and spacecraft heating environments due to particle radiation from a single nozzle rocket exhaust plume. The technique has proved successful when applied to a single nozzle exhausting into a rarefied atmosphere on the basis of comparison of predictions with experimental results. The analysis treats radiation from a cloud of particles as that from an equivalent radiating surface. Thus, the problem is reduced to the determination of the proper values of the apparent surface emissivity and the effective temperature. In defining the apparent emissivity of the particle plume, an analogy with neutron scattering for a cylindrical cloud is adopted which shows the apparent emissivity to be dependent on particle emissivity and cloud optical thickness. Since the plume is non-uniform in particle size, concentration, and temperature, certain averaging techniques are used to define values of optical thickness and temperature.