Study on collision law of condensed particles in secondary combustor of unchoked solid ducted motor

Based on O'Rourkes droplet collision and coalescence model, moving process of condensed particles in secondary combustor of solid ducted rocket motor was numerically simulated by using Euler-Lagrangian method. The influence of injection nozzle configuration on collision number was analyzed. The results indicate that the number of primary nozzle orifice plays an important role for collision number of condensed particles, and collision number of condensed particles released from injection nozzle with seven ports is much more than that of three ports. The increase of the angle between centerline of nozzle orifice and axis of secondary combustor can promote collision number, but the effect is small. The collision momentum of condensed particles has little relation with the injection nozzle configuration under the same primary nozzle equivalent diameter.