Numerical Analysis of Droplet Impact on the Convex Surface with Liquid Film.

Abstract

Droplet impact on film is a common natural appearance in industrial production. The numerical simulation method is used to simulate the evolution process of droplet impact on different convex surfaces with liquid film to study the influence of various surface structures on the impact of droplets on the film. The mechanism of droplet impact on irregular wall is also explored. The effect of the height and width of the convex on the evolution of the interphase interface and the characteristic parameters of the crown and cavity are discussed. Based on the results, the convex has a great effect on the change form of droplets after impacting the liquid film. A region of high pressure will appear above the convex, and vortices will form around it. In terms of the characteristics of the crown, the growth rate of the crown height increases with the height of the convex. The spreading diameter of the crown increases with the height of the convex. The effect of convex width on the crown is less than that of convex height. The convex has a great influence on the evolution of the cavity, and the convex of different scales will affect the development shape of the cavity. The present finding provides theoretical guidance for the application of droplets impinging on liquid film.