Calculation of particle trajectories in solid-rocket motors with arbitrary acceleration

Abstract

The particle trajectories in a solid-rocket motor under several acceleration conditions have been simulated using a combined Eulerian-Lagrangian analysis. This analysis uses the numerical solution of ensemble-averaged Navier-Stokes equations for the continuous phase, coupled with a Lagrangiah analysis for the discrete (particulate) phase to simulate the two-phase internal flow. A Linearized Block Implicit scheme is used to solve the governing equations for the continuous phase, which allows the use of a highly stretched grid with sublayer resolution. The motion of the particles is tracked in computational coordinate space resulting in computational efficiency. The governing equations are written in generalized noninertial reference frame so that effect of motor acceleration can be easily included. While the analysis allows complete-coupled calculations, the present study has neglected the effect of the participate phase on the gas-phase flowfield. Particle trajectories under specified acceleration conditions, that include axial acceleration, axial and lateral acceleration, as well as a centrifuge test for a tandem pulse rocket motor have been calculated. The calculated results indicate that the acceleration effects strongly influence the particle impingement patterns on the motor case and the nozzle.