雾化液滴在气道内的动力学特性及其影响因素

Dynamic behavior of atomized droplet in gas duct and its influencing factors

基于单颗粒动力学,用Lagrangian方法建立了液滴在气道内运动的数学模型,用Runge-Kutta法对液滴运动方程进行了数值求解,得到了液滴速度、相对雷诺数和阻力系数沿气道轴向的变化规律,并分析了重力场、液滴粒径、液滴初始速度、液滴出射角度对液滴运动轨迹的影响。结果表明,液滴在气道内的运动分为变速段和恒速段,液滴粒径、初始速度及出射角度等因素对雾滴的运动轨迹也有很大影响,雾滴运动分析时一般不应忽略重力场的作用。

The mathematical model of dispersed droplet moving in the duct was established based on single particle dynamics in the Lagrangian framework. A Runge-Kutta explicit method was used to solve the formulations. The droplet velocities, the relative Reynolds number and drag coefficient along the gas duct were analyzed. Also, an analysis was given to the effect of the gravity field, the droplet diameter, the droplet＇s initial velocity and the droplet＇s jet angle on its movement trajectories in the duct. The results indicate that the movement of the droplet can be divided into variable velocity process and constant velocity process, and that the factors such as the droplet diameter, the droplet＇s initial velocity and the droplet＇s jet angle significantly influence the droplet＇s movement trajectories, and that the gravity field should not be ignored during the droplet＇s movement analysis.