凝胶模拟液液滴碰撞的SPH数值仿真

Numerical simulation of gel simulants droplets collision with SPH method

雾化问题是凝胶推进技术研究的关键问题,雾化过程中不可避免地会出现液滴的碰撞。通过SPH方法对凝胶推进剂模拟液液滴的碰撞过程进行了数值模拟。针对气-液交界面处存在较大的密度、粘度梯度,对传统SPH方法做出改进。在此基础上,对空气中两个同尺寸的凝胶液滴碰撞过程进行了数值模拟,并与水滴的碰撞进行了对比,分析了凝胶推进剂的流变特性对于碰撞结果的影响。结果表明,凝胶液滴的碰撞动能在高粘度的作用下迅速耗散,液滴碰撞后,更易发生聚合,进一步增加了凝胶推进剂雾化的难度。

Atomization is one of the key problems in the research of gel propulsion technology,and it is inevitable that there will be droplets collisions in the process of atomization.In this paper,SPH method is used to simulate the collision process of gelled propellants simulants droplets.In the view of the large density,and viscosity gradient at the gas-liquid interface,the traditional SPH method is improved.On this foundation,collisions of two gelled droplets of the same size in the air were simulated,which were compared with water droplets collision,and the influence of rheological properties of gelled propellant on collision results were analyzed.The results show that the collision kinetic energy of gelled droplets is rapidly dissipated under the action of high viscosity,and hence it is easier to polymerize after the collision,which further increases the difficulty of atomization of the gelled propellants.