A particle-gridless hybrid method for incompressible flows

A particle-gridless hybrid method for the analysis of incompressible flows is presented. The numerical scheme consists of Lagrangian and Eulerian phas es as in an arbitrary Lagrangian-Eulerian (ALE) method, where a new-time ph ysical property at an arbitrary position is determined by introducing an ar tificial velocity. For the Lagrangian calculation, the moving-particle semi -implicit (MPS) method is used. Diffusion and pressure gradient terms of th e Navier-Stokes equation are calculated using the particle interaction mode ls of the MPS method. As an incompressible condition, divergence of velocit y is used while the particle number density is kept constant in the MPS met hod. For the Eulerian calculation, an accurate and stable convection scheme is developed. This convection scheme is based on a flow directional local grid so that it can be applied to multi-dimensional convection problems eas ily. A two-dimensional pure convection problem is calculated and a more acc urate and stable solution is obtained compared with other schemes. The part icle-gridless hybrid method is applied to the analysis of sloshing problems . The amplitude and period of sloshing are predicted accurately by the pres ent method. The range of the occurrence of self-induced sloshing predicted by the present method shows good agreement with the experimental data. Calc ulations have succeeded even for the higher injection velocity range, where the grid method fails to simulate. Copyright (C) 1999 John Wiley & Sons, L td.