Numerical Simulation Of Multiple Droplets Impingement Upon Liquid Film

Droplet impingement phenomenon and its application are common and widely existed in nature,industry and agriculture.The research on the impact process of droplet is of great significance.There are many studies about the droplet impingement on the solid surface and deep pool.Few efforts has been made to investigate the phenomenon of the droplet impact on the liquid film,especially multiple droplets impingement.Based on the numerical simulation,the flow performance and dynamics of single,double and triple droplets impingement on liquid film have been studied.Firstly,the two-dimensional model of single,double and triple droplets impingement on liquid has been performed.Based on the numerical results,the flow performance of different numbers of droplets impinging on the liquid film was studied.By comparing and analyzing the velocity distribution and pressure distribution in the impact process with time,the development of the droplet impact process has been expounded.The differences in the flow performance of different numbers of droplets impingement on the liquid film has been discussed.By comparing and analyzing the characteristic curvature of splash,central jet and cavity in each case,the differences in the dynamics of different numbers of droplets impingement has been discussed.The conclusion is:Compared with single droplet impingement on liquid film,the flow performance of multiple droplets impingement on liquid film is not only affected by itself,but also affected by mutual effect among multiple droplets.Secondly,based on the two-dimensional model of multiple droplets,the influence of the impact velocity,the initial film thickness and the horizontal distance between droplets have been studied on the impact process of single,double and triple droplets.By comparing and analyzing the evolution process of free surface under different impact parameters,the influence of the impact parameters on the evolution of splash,central jet and cavity have been discussed.Then,the trend of characteristic curvature of splash,central jet and cavity under different impact parameters have been studied.The influence law of each impact parameter is discussed.The conclusion is:The impact velocity has a great influence on the impact process,and the effect is different as the number of droplets changes.The initial film thickness nearly has no effect on the evolution process of the free surface during the impact.The horizontal distance is the main factor affecting the shape and characteristic parameters of the central jet.