The impact and aggregation of multiple alumina droplets on the inner wall of the solid rocket motor may generate a larger rebound aggregated droplet or adhere to the wall to form a liquid film. The rebound and adhesion characteristics of the aggregated droplet are of great significance for slag deposition and two-phase flow prediction in the motor. In this paper, the VOF (Volume of fluid) method is used to study the impact and aggregation process of multiple alumina droplets on the wall. Detailed numerical verifications are carried out, including the impact and aggregation of moving droplets, the aggregation and rebound of stationary droplets and the impact process of a single alumina droplet on the wall. It is found that the aggregated droplet will rotate when two droplets aggregate under small droplet diameter ratio, which is caused by the asymmetry aggregation process. The oscillation process intensifies when three droplets impact and aggregate on the wall, as a result, the aggregated droplet is easier to adhere to the wall. The viscous dissipation in the aggregation of droplets is huge, and the total viscous dissipation energy accounts for about 50% of the total energy when the aggregated droplets rebound. The influence of droplet diameter on the $V^{⁎}$ (rebound recovery coefficient) of the aggregated droplet and the rebound/adhesion results are dominated by the viscosity effect. While the influence of the parameters involving the initial spatial arrangement of droplets is dominated by the oscillation process, which will reduce the effective rebound kinetic energy, making a lower $V^{⁎}$ and the aggregated droplet easier to adhere.

多个氧化铝液滴对固体火箭发动机内壁的撞击和聚集可能会产生较大的反弹聚集液滴或粘附在壁上形成液膜。聚集液滴的回弹和粘附特性对电机内的熔渣沉积和两相流预测具有重要意义。本文采用VOF（Volume of fluid）方法研究了多个氧化铝液滴对壁面的冲击和聚集过程。进行了详细的数值验证，包括运动液滴的冲击和聚集、静止液滴的聚集和反弹以及单个氧化铝液滴对壁面的冲击过程。发现当两个液滴在小液滴直径比下聚集时，聚集的液滴会旋转，这是由不对称聚集过程引起的。当三个液滴撞击并聚集在壁上时，振荡过程加剧，结果，聚集的液滴更容易粘附在壁上。液滴聚集过程中的粘性耗散量巨大，粘性耗散总能量约占聚集液滴反弹时总能量的50%。液滴直径对液滴的影响$V^{⁎}$聚集液滴的（回弹恢复系数）和回弹/粘附结果由粘度效应决定。而涉及液滴初始空间排列的参数的影响以振荡过程为主，这会降低有效回弹动能，使液滴较低$V^{⁎}$并且聚集的液滴更容易粘附。