Research on the collision model of high-temperature alumina droplets with cold wall for solid rocket motors

The study on the adhesion and rebound behavior of high-temperature alumina droplets impacting on the cold wall is very meaningful for the accurate prediction of slag deposition and internal flow field in solid rocket motors. In this paper, based on high-temperature alumina droplet impact experimental system, the experiment of alumina droplet impacting on the cold wall was carried out, and the temperature response of alumina droplet during the impact is obtained by the colorimetric thermometry. The study shows that the high-temperature alumina droplets impacting on the cold wall in a certain range of Oh number and Re number exhibit two kinds of behaviors: rebound and adhesion; based on experiments, the distribution laws of rebound and adhesion behaviors of alumina droplets impacting the cold wall are obtained; based on the energy conservation model, and introducing the heat transfer model between the high-temperature droplet and the cold wall, the maximum spreading coefficient model of alumina droplet impact on the cold wall and the prediction model of rebound and adhesion results were established, and the maximum spreading coefficient model prediction results were in good agreement with the experimental data.