Universal erosive burning model performance for solid rocket motor internal ballistics

Abstract

The erosive burning of solid rocket propellant is an area of concern for high L/D rocket motors. Several explanations for the different causes for this phenomenon exist along with the modelling practices to predict the effects based on these causes. Universal nature of the erosive burning process was proposed by Mukunda and Paul irrespective of size, shape and type of the propellant. In the present work, the same model is applied for cylindrical port motors with high and moderate mass flux, as well as finocyl grain motors. It is observed that for cylindrical port motors, computed pressures with the burning time match very well experimental data. A modified form of the model (which becomes the original model for axisymmetric port) is used for finocyl geometries and a good prediction of pressures is observed. This study confirms the universality of the Mukunda and Paul model in its modified form which addresses non-axisymmetric port geometries also. The simplicity of the model makes it a useful tool for design and analysis of solid rocket motors of any size and port geometry.