Fluidparticle flow and validation using twowaycoupled mesoscale SPHDEM
Abstract
First, a meshless simulation method is presented for multiphase fluidparticle flows with a twoway coupled Smoothed Particle Hydrodynamics (SPH) for the fluid and the Discrete Element Method (DEM) for the solid phase. The unresolved fluid model, based on the locally averaged Navier Stokes equations, is expected to be considerably faster than fully resolved models. Furthermore, in contrast to similar meshbased Discrete Particle Methods (DPMs), our purely particlebased method enjoys the flexibility that comes from the lack of a prescribed mesh. It is suitable for problems such as free surface flow or flow around complex, moving and/or intermeshed geometries and is applicable to both dilute and dense particle flows. Second, a comprehensive validation procedure for fluidparticle simulations is presented and applied here to the SPHDEM method, using simulations of single and multiple particle sedimentation in a 3D fluid column and comparison with analytical models. Millimetresized particles are used along with three different test fluids: air, water and a waterglycerol solution. The velocity evolution for a single particle compares well (less than 1% error) with the analytical solution as long as the fluid resolution is coarser than two times the particle diameter. Two more complex multiple particle sedimentation problems (sedimentation of a homogeneous porous block and an inhomogeneous Rayleigh Taylor instability) are also reproduced well for porosities 0.6 <= \epsilon <= 1.0, although care should be taken in the presence of high porosity gradients. Overall the SPHDEM method successfully reproduces quantitatively the expected behaviour in the test cases, and promises to be a flexible and accurate tool for other, realistic fluidparticle system simulations.
 Publication:

arXiv eprints
 Pub Date:
 January 2013
 arXiv:
 arXiv:1301.0752
 Bibcode:
 2013arXiv1301.0752R
 Keywords:

 Physics  Fluid Dynamics;
 Physics  Computational Physics
 EPrint:
 45 pages, 14 figures