Numerical study of the process of liquid droplets impacting the curved wall surface

The impact of droplets on the solid wall is a typical free surface flow phenomenon that widely exists in nature, industry, and daily life. According to the change of the droplet's center thickness, the droplet, the spreading process of the droplet is usually divided into three unique stages: the initial droplet deformation stage, the inertia-dominated stage, and the viscosity-dominated stage with the increase of the impact time. The problem of the liquid droplet spreading under different impact conditions is simulated by the smoothed particle hydrodynamics (SPH) method. Firstly, the dynamic process of droplet spreading is simulated and compared with relevant experimental results to verify the effectiveness of the proposed method. Then, the effects of the Weber number and the diameter ratio of the droplet to the curved wall surface on the droplet's maximum spreading diameter and central thickness were studied and analyzed. On this basis, the key coefficient in the existing relationship between the Weber number and maximum spreading diameter is fitted. Finally, the fitting equation of the center thickness and the impact time in the third stage of droplet spreading is assessed.