Research on Characteristics of Paint Deposition on Spherical Surface

Abstract

  In order to describe the two-phase coupling flow process of paint deposition on spherical surface, the Euler-Lagrange method was used to establish the model of paint deposition on spherical surface, including continuous phase model, discrete phase model as well as impinging and sticking model. Polyhedral mesh and SIMPLE algorithm were used to solve this model. According to the results of numerical simulation, the spray flow field of paint deposition on spherical surface and flat almost has the same form in the diffusion zone, but in the paint-deposition zone, the gas phase velocity and the coverage of the spray flow field on spherical surface are larger than those on flat. The main source for forming the paint film is large-diameter particles and medium-diameter particles in the spray flow field. The shape of paint films on the spherical surface is a spherical surface, of which the projection on axial direction is an oval, while it is an oval on flat, and the film thickness decreases along the elliptical radial direction. By comparison, the film thickness on spherical surface is thinner than that on flat, and the coverage of film distribution and the painting rate on spherical surface are smaller than those on flat. However, the uniformity of paint film on spherical surface is better than that on flat. As the diameter of spherical surface increases, the coverage of film distribution and the uniformity of film thickness increase，and the film thickness and the painting rate also increase. The characteristics of paint deposition on spherical surface were verified by experiments.

Keywords: paint deposition,  spray flow field,  two phase flow,  computational fluid dynamics