Abstract: A Lagrange particle method based on SPH(Smoothed particle hydrodynamics) is presented to simulate the free surface incompressible fluid flow. Field variables and their derivatives are evaluated through interpolation of kernel function without need of any mesh. A fractional step method is used in time integration, which stabilizes the computation of pressure. Owing to the virtue of Lagrangian formulation, the smearing of free surface resulting from the numerical diffusion for convective terms is eliminated completely. The method is applied to simulate a benchmark breaking dam problem. The simulation results agree well with the experimental results although fragmentation and coalescence take place.

Key words: Fractional step method, Free surface, Incompressible fluid flow, SPH