二流体雾化器雾化过程仿真及实验

探究了二流体雾化器液膜破碎过程与液滴形成过程,对不同螺距和喷嘴出口形状的二流体雾化器喷嘴进行仿真研究。仿真分析了二流体雾化器的液膜形成与破碎过程,通过耦合VOF-DPM模型,成功获得了雾化过程中的液滴粒径尺寸分布,并通过实验验证仿真结果的准确性。研究结果表明：二流体雾化器中螺距对气相的速度影响较大,高速的气相从出口流出时会形成较大湍流抬升导液管附近液相；不同的喷嘴结构会导致液相延伸的长度和一次破碎完成的时间不同,气相的速度越高二次破碎能产生粒径更小的液滴颗粒；气相速度较低的喷嘴二次破碎过程以液团形式完成二次破碎,气相速度较高的喷嘴则以液带形式完成二次破碎。

Simulation and Experimental of Atomization Process in a Two Fluid Atomizer

In order to realize the accurate numerical simulation of the two- fluid atomization process, explore the process of liquid film breaking and droplet formation of the two fluid atomizer, and carry out simulation research on the two fluid atomizer nozzles with different pitch and nozzle exit shapes. The simulation results reveal the formation and breaking process of the liquid film in the two-fluid atomizer, and successfully obtain the droplet size distribution in the atomization process by coupling the VOF-DPM model, and verify the accuracy of the simulation results through experiments. The results show that the pitch of the two fluid atomizer has a great influence on the velocity of the gas phase, and when the high-speed gas phase flows out of the outlet, it will form a large turbulence to lift the liquid phase near the liquid guide tube; Different nozzle structures will lead to different length of liquid phase extension and completion time of one crushing; The higher the velocity of the gas phase, the smaller the particle size can be generated by secondary crushing. The secondary crushing process of nozzle with low gas phase velocity is completed in the form of liquid mass, while the secondary crushing process of nozzle with high gas phase velocity is completed in the form of liquid strip.