Prediction of the radiative base heating from the solid rocket exhaust plume

In this study, the thermal fields with radiative heat transfer from a solid rocket exhaust plume and the behavior of solid particles under varying altitudes and flight velocities were investigated numerically. Simulations were conducted using ANSYS Fluent, incorporating coupled models for the internal and external turbulent flow, afterburning chemistry, particle dynamics, and radiative heat transfer. This study distinguishes by establishing a coupled multi-physics framework that quantifies the combined effects of reacting afterburning, particle dynamics, and thermal radiation under various flight conditions. After introducing the mathematical formulations for the reacting flows with thermal radiation, the present approach was validated through a comparison with previous studies available in the literature. The results showed that afterburning occurred in the mixing layer of the plume, generating additional chemical species and increasing the local temperatures by more than 1000 K. This temperature rise substantially enhanced radiative transfer, leading to an increase in the base-plane heat flux by more than 0.8 kW/m². Although the plume expansion at higher altitudes increased the base-plane view factor, the accompanying reduction in oxygen density, gas temperature, and particle concentration outweighed this geometric effect, resulting in an overall decrease in the radiative heat flux to the base plane by 31.73% over the altitude range of 0 to 30 km.