Simulation of Solid Propellant Regression with Cracks Based on Level-Set Method

Abstract

Traditional methods are difficult to deal with solid propellant regression in complex geometry, especially for a finocyl grain with cracks. In this work, the Level-Set method is adapted to solid propellant regression. The advantage of this method is the implicit representation of interface and no restriction on geometrical configuration. Therefore, tiny cracks can be easily captured by the Level-Set method without any complex grids. A three-dimensional solid propellant regression evolution process of a finocyl grain is presented. A one-dimensional unsteady internal ballistics numerical method is applied to obtain pressure and thrust time histories, coupled with the three-dimensional grain burnback model. The mass and energy injection in the governing equations can be computed from the Level-Set formulation. And the propellant burning rate can be computed from the local pressure. The results show that a crack increases the head-end pressure and thrust at early stage, because of the increment of the burning surface area. It can be seen from the evolution of propellant regression that the crack gradually expands.