二流体雾化器雾化过程仿真及试验

Simulation and Experimental of Atomization Process in Two Fluid Atomizer

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,并通过试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的液滴颗粒粒径越小;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。

Process of liquid film fragmentation and droplet formation in a two fluid atomizer was explored,and two fluid atomizer nozzles with different pitches and nozzle outlet shapes were conducted simulation research.The process of liquid film formation and fragmentation in a two fluid atomizer was simulated and analyzed.By coupling VOF-DPM model,droplet size distribution during atomization process was successfully obtained,and accuracy of simulation results was verified through experiments.Research results indicated that pitch in a two fluid atomizer had a significant impact on velocity of gas phase,and when high-speed gas phase flowed out of the outlet,it formed a large turbulence to lift liquid phase near guide pipe.Different nozzle structures could result in different lengths of liquid phase extension and different completion times for primary crushing.The higher the gas phase velocity,the smaller the droplet size produced by secondary crushing.For nozzles with lower gas phase velocity,secondary crushing was completed in form of liquid mass,while for nozzles with higher gas phase velocity,secondary crushing was completed in form of liquid belt.