Fully-coupled pressure-based two-fluid solver for the solution of turbulent fluid-particle systems

Abstract

A fully-coupled pressure-based two-fluid solver for the solution of turbulent fluid-particle flows is presented. The numerical framework details several crucial aspects: implicit treatment of the phase-velocity-pressure coupling, the implicit treatment of inter-phase momentum transfer and finally the solution algorithm. The two-fluid solver is implemented within the open source tool-box foam-extend which is a community driven fork of OpenFOAM. The coupled solver is verified against a standard segregated implementation of the two-fluid solution algorithm and validated against benchmark experimental data. The coupled solver shows marked improvements in convergence, stability and solution time. The coupled implementation is capable of solving to a tolerance that is six orders of magnitude smaller in residual error and 1.7 times quicker than the segregated solver. Additionally, the sequentially solved system of phase-energies experienced performance improvements when solved in conjunction with the coupled solver.