NUMERICAL STUDY AND ABLATION PREDICTION ON 3-D TWO-PHASE FLOW FIELD FOR TAIL-PIPE NOZZLE SRM UNDER HIGH ACCELERATION

摘要

Numerical simulations of three-dimension two-phase flow field of tail-pipe nozzle SRM were carried out using Euler-Lagrange model. Influences of different particle diameter, longitudinal and lateral acceleration, and aluminum powder content on particle distribution characteristics were analyzed. The results showed that the difference between gas flow field and two-phase flow field was evident; with the increasing of particle diameter, the particle concentration increased, and the change of particle movement rule was obvious; the change of acceleration markedly influenced particle distribution of grain segment, inconspicuously influenced tail-pipe segment; lateral acceleration was more distinctly influenced particle trajectory and concentration than longitudinal acceleration; with the increase of aluminum powder percentage, the particle concentration rised. It was considered that the mechanical denudation of particles directly intensified thermal insulator ablation. Ablation prediction showed that thermal insulator ablation in aft closure was greater than that in tail-pipe nozzle. This was because the mechanism of ablation in aft closure was highly concentrated particle eroding, while the ablation mechanism in tail-pipe nozzle was thermal chemistry ablation of high-speed gas flow.