High Altitude Plume Simulations for a Solid Propellant Rocket

Abstract

A simulation scheme is proposed for flowfield and radiation analysis of solid rocket exhaust plumes at high altitude. Several recently developed numerical procedures are used to determine properties of the gas and condensed phase Al2O3 particles, and spectrally resolved plume radiation calculations are performed using a Monte Carlo ray trace model. Simulations are run for a representative plume flow at 114 km, and a comparison is made with experimental measurements of UV radiance. A series of parametric studies involving simulations of this same flow are used to evaluate the influence of physical processes and input parameters related to gas-particle interaction, particle radiation, and the presence of soot. I. Introduction n of m the flowfield simulation and radiation analysis of solid rocket exhaust plumes at very high altitudes, a number approximations and simplifying assumptions are typically made due to computational cost, a lack of existing odels, or uncertainty over the influence of various physical phenomena. These flows tend to include a large mass fraction of Al2O3 particles, which can significantly influence bulk flow properties and dominate plume radiative emission through much of the IR, visible, and UV range. Some determination of particle phase characteristics is typically required for useful and accurate simulation results, and may be necessary to assess base heating rates, radiation signatures, surface contamination effects, or other flow properties of interest. As a result, important physical processes and phenomena associated with gas-particle interaction must be recognized and incorporated into simulation procedures. Several potentially important effects have received little attention in the literature, and the significance of coupling between many of these effects still remains an open question. In this paper, we attempt to address the uncertainty in the significance of various effects, and describe a general procedure for the simulation of rarefied plume flows from solid propellant rockets. I