Numerical Simulation of Two Droplets Impinging Successively on a Hot Solid in the Film Boiling Regime

Abstract

The deformation mechanics of two droplets impinging successively on a hot solid at small impact velocities was investigated by carrying out computer simulations. The conservation equations for mass, momentum, and energy for unsteady incompressible viscous fluids in an axisymmetric coordinate system were approximated and solved with a finite difference method, taking account of gravity, viscosity, and surface tension. It was assumed that a thin vapor layer forms between the water droplet and the solid surface immediately after impact. The numerical results were compared with those of experiments. It was found that the liquid deforms into a crown shape during the successive impacts. The fluid mechanics of the interactions of the droplets is discussed in detail.