Analytical and numerical burnback analysis of end burner grain with cylindrical cavity

Abstract

Burnback analysis is a critical stage in the design of solid propellant rocket motors. This paper will focus on investigating the burnback analysis of an end burner grain with central cylindrical cavity. Analytical and numerical methods for evaluating the burning surface area have been used. The analytical geometrical equations that illustrate the burning surface area evolution were developed for the two-phase burning process. The first phase is the boost phase and the second phase is the sustaining which lasts longer. A parametric model of the grain was also created in PTC Creo to simulate the burn back numerically. The results from both methods show an agreement which approves that the numerical method could be used for complex grain shapes, for which it is difficult to obtain the analytical solution. Furthermore, a MATLAB program was developed in order to compare the numerical and analytical results and to predict some of the main interior ballistics parameters.