Influence of optical properties of alumina particles on the radiative base heating from solid rocket plume

Abstract

The radiative properties are obtained from the optical properties of alumina particles and applied to the discrete ordinate interpolation method to calculate the radiative base heating. During this process, the radiative properties are thoroughly investigated by considering particle size and temperature variation. The plume model is divided into two cases depending on whether the scattering effect is included or not. In the case of the plume emission only model, the optical properties including the absorption index significantly affect radiative base heating. However, when scattering is also considered, the influence of the optical properties on base heating is reduced due to the effect of the large scattering coefficient acting as a barrier for the optically thick condition. However, the maximum heating rate is still approximately 2.2 times larger than minimum one. As such, the appropriate selection of optical properties is important. To determine the feasibility of this study, calculated heating values for the plume model whose shape, mass portion of alumina, etc. are obtained from the KSLV-I kick motor are compared to the measured data derived from the kick motor test. Although the conditions are not the same, the calculated data range is from 34.2 kW/m2 to 74.1 kW/m2 based on the optical properties, which is not much far from the measured data. This implies that the results obtained are at least reasonable to a certain extent.