3D Lagrangian Modelling of Viscous and Inviscid incompressible Flow Using Conservative and Non-conservative Riemann Solvers and Density Filtering

In this paper, 3D numerical lagrangian modelling of flow was performed using Weakly Compressible Smoothed Particle Hydrodynamic (WCSPH) method. Navier Stokes and Euler Equations were used to simulate viscous and inviscid fluid flow respectively. The fluid flow was assumed in three forms of inviscid, with artificial viscosity and viscous fluid flow with turbulence. Although the WCSPH method is acceptable for simulating of free surface, but has a major problem of large and non-physical oscillations in pressure and velocity field. In this paper the effect of density filtering, conservative and non-conservative Riemann solvers were studied for correction of pressure and velocity of WCSPH results. Furthermore due to using of laminar and SPS turbulence method with non-conservative Riemann, the effect of using kernel gradient correction was also studied. Therefore five numerical methods were introduced for simulating 3D incompressible fluid flow. The results of these numerical models were compared with experimental data. The comparison showed that using Riemann solvers and especially non-conservative Riemann solver with kernel gradient correction gives acceptable results for pressure and velocity field of numerical results. Finally the validation of numerical model was also performed for the variation of free surface.