可调离心式喷嘴喷雾流场的数值模拟研究

Numerical Simulation of Spray Flow Processes in Adjustable Centrifugal Nozzle

建立了可调离心式喷嘴三维CFD(计算流体动力学)模型。应用FLUENT软件对该喷嘴的喷雾流场进行了模拟分析。连续相采用三维可压缩稳态雷诺时均N-S方程,湍流模型采用标准的k-ε模型,通过SIM PLE算法求解压力速度耦合,离散相采用拉格朗日方法追踪颗粒运动轨迹。模拟结果给出了喷嘴喷雾流场随着时间的变化规律、喷嘴压差对喷嘴的雾化性能以及液滴分布特性的影响,得出了不同流量下索太尔平均直径(SMD)和液滴分布指数随着喷嘴压差的变化规律,模拟得到的索太尔平均直径与实验值吻合良好。

A numerical investigation is performed to explore the characteristic of spray produced by an adjustable centrifugal nozzle. A three-dimension CFD （Computational Fluid Dynamics） model based on the Eulerian-Lagrangian method with adaptive grid generation scheme is established. This model is employed to study the effect of injecting pressure drop and flow flux on the Sauter Mean Diameter（SMD） and droplet spread parameter. The simulation results show that an increase in pressure drop produces a decrease in SMD and a decrease in droplet spread parameter; and that an increase in flow flux produces an increase in SMD and an increase in droplet spread parameter; and that the numerical prediction of Sauter Mean Diameter agrees well with its experimental measurement.