Modeling crown formation due to the splashing of a droplet

The typical crown formation created by the impact of a single drop on a slightly wetted target surface is treated as a series of two surfaces of discontinuity from which the jump momentum and mass equations are developed along with the governing equation for crown radius. The crown radius equation is solved in conjunction with the governing equations of the flow emanating from drop/wall impact. This flow is modeled initially as a cylindrical region of prescribed height and velocity. Both viscid and inviscid situations are treated. For the inviscid case of a crown moving through a motionless film, analytical solutions are found for the evolution of film height and velocity. For the viscid situation, a numerical scheme based on the discretization of the governing equations along the characteristic directions is employed. The results are validated by comparing with experimental and computational results from the literature. The effects of target surface film height, velocity, and wall friction on the crown dynamics are investigated. (C) 2001 American Institute of Physics.