入口雷诺数对压力旋流喷嘴雾化特性的影响

Effects of Inflow Reynolds Number on Spray Characteristics of a Pressure Swirl Atomization Nozzle

为了揭示介质流量和介质黏度在压力喷嘴雾化过程中的作用机制,采用大涡模拟(LES)与体积函数模型(VOF)相结合的模拟方法,探究了喷嘴内部流动情况,分析了入口雷诺数对喷嘴流量系数、雾化角和雾化粒径等雾化特性的影响。结果表明:随着雷诺数的增加,喷嘴出口液膜厚度变薄,喷嘴流量系数降低;在高雷诺数下,流量系数受其影响较小;随着雷诺数增加,喷嘴雾化角增大,当雷诺数低于1000时,雾化角增大现象更为明显,相同雷诺数下雾化角几乎相等;当雷诺数较高时,雾化液滴索特平均粒径更均匀,液滴粒径分布更接近R-R分布特征。

In order to reveal the mechanism of the medium flow and viscosity in the atomization process of pressure nozzle,a simulation approach combining large eddy simulation(LES)and volume of fluid(VOF)was adopted to explore the flow in the nozzle,and the effects of inflow Reynolds number(Re)on flow coefficient,atomization angle and particle size were analyzed.Results show that the flow coefficient of the nozzle and the liquid film thickness at the nozzle outlet decrease with the increase of Re.When Reis high,the effect of inflow Re on the flow coefficient is less.With the increase of Re,the atomization angle of the nozzle increases.When Reis less than 1000,the increase of atomization angle is more obvious with the increase of Re.For a certain Re,the atomization angle is almost equal.When Reis higher,the Sauter mean diameters(dSMD)of atomized droplets are more uniform,and the distribution of the atomization particle size is closer to the characteristics of Rosin-Rammler(R-R)function.