Efficient Solution Approach for Internal Ballistics

This paper presents an efficient approach to solve for the internal ballistics in a solid rocket motor. Legacy methods consist primarily of lower-order (one-dimensional) and higher-order (volume-based RANS CFD) schemes. For medium complexity solutions, previous researchers have produced analytic solutions for special cases including axisymmetric and planar flows. This work extends the medium fidelity solution methods to include three-dimensional and more complex axisymmetric grain configurations. The primary building block for this approach is a tool known as FlightStream®, originally developed for external aircraft aerodynamics analysis applications. FlightStream® solves the vorticity formulation of the potential flow equations. This paper provides an overview of the method, a description of several sample geometries, and a collection of illustrative results including the ability to predict erosive burning characteristics in motors with practical grain perforations such as the conical, finocyl, and spherical configurations.