高温熔融液滴碰撞过程及模型研究

固体火箭发动机中三氧化二铝和铝微粒为高温熔融液滴，在发动机内流动过程中会发生碰撞，导致液滴直径和速度分布等参数发生改变，影响发动机的正常工作性能。本项目采用实验拍摄、直接数值模拟和理论推导相结合的方法，针对高温熔融三氧化二铝和铝液滴碰撞过程及模型进行研究。首先通过实验拍摄和数值计算分别研究液滴尺寸大小、尺寸比、环境气体压强和燃烧对液滴碰撞的影响。分析总结研究结果，获得不同液滴碰撞结果类型的物理机理和形成条件，并揭示各因素对液滴碰撞的影响机理。基于粘性流体动力学理论和液滴碰撞机理，建立粘性液滴碰撞物理模型，包括液滴反弹模型、聚合模型、自反分离模型、拉伸分离模型以及分离后子液滴参数计算模型等。将粘性液滴碰撞模型嵌入固体火箭发动机多物理模型数值计算方法中，模拟考虑液滴碰撞发动机工作过程的内流场，为不同发动机工作性能预测和设计提供更准确的研究方法。

Alumina and aluminum fine particles in solid rocket motor are high temperature molten droplets, which collide with each other as flowing in the motor, changing the parameters as the diameter and velocity distributions of droplets, then it affects the performance of motor. This project employs experimental photographing, direct numerical simulation and theoretical method to investigate the collision of molten alumina and aluminum droplets with high temperature and its model. First, the effects of droplet size, size ratio, environmental pressure and combustion on droplet collision should be investigated experimentally and numerically. Analyzing all the data obtained by experiments and simulations, the mechanisms and resulting conditions of different outcomes will be obtained, and the effect mechanism of different factors on droplet collision will be revealed. On the basis of viscous fluid dynamics and droplet collision mechanisms, the droplet collisions will be modeled, including bouncing model, coalescence model, reflexive separation model, stretching separation model andparameter calculating model of satellite droplets. Embedding the collision models in the multi-physics numerical method of solid rocket motor to simulate the intern flow field of motor, it provides a more precise method for the prediction of motor performance and design.