高温燃气中铝凝相粒子壁面碰撞行为影响因素研究

Influencing Factors of Collision Behavior Between Aluminum Particles and Wall in High-Temperature Gas

关键词:  固体火箭发动机  熔渣  铝粒子  碰撞  沉积

Key words:  Solid rocket motor  Slag accumulation  Aluminum particles  Collision  Deposition

摘要:

为了探究发动机内凝相铝的沉积规律，采用高温甲烷/氧气火焰模拟固体火箭发动机工作的高温环境。在前期研究的基础上，重点关注壁面温度和材料对凝相铝沉积概率的影响。实验结果表明，碰撞速度以及壁面的材料和温度都会影响铝粒子的碰撞后行为和沉积概率；沉积的主要机理是粒子在壁面上的传热导致粒子发生冷却凝固，从而产生强大的粘附力；壁面温度过低会导致粒子过快冷却，降低粒子与壁面之间的粘附力，从而降低沉积概率；壁面材料的热导率以及力学性能也会对沉积概率产生影响。

Abstract:

To investigate the deposition pattern of condensed-phase aluminium inside the engine， a high-temperature methane/oxygen flame was used to simulate the high-temperature environment of a solid rocket motor. Based on the previous study， this work focuses on the effects of wall temperature and material on the deposition probability of condensed-phase aluminium. The experimental results show that the collision velocity， as well as the wall material and temperature， affect the post-collision behaviour and deposition probability of aluminium droplets. The main mechanism of deposition is that the heat transfer of droplets on the wall leads to cooling and solidification of particles， resulting in a strong adhesion force. However， a much low wall temperature leads to rapid cooling of particles and reduces the adhesion force between particles and the wall， thus reducing the deposition probability. The thermal conductivity and mechanical properties of the wall material also have an impact on the deposition probability.