From 583fc4aec0ada4066ad67596d51135d92e5ddb03 Mon Sep 17 00:00:00 2001 From: Henry Weller Date: Tue, 17 May 2022 14:01:59 +0100 Subject: [PATCH] driftFluxFoam::relativeVelocityModel: Updated dispersed-phase flow acceleration estimate // Dispersed phase velocity // const volVectorField Ud(mixture_.U() + Udm_); // Use the mixture rather than the dispersed-phase velocity to approximate // the dispersed-phase acceleration to improve stability as only the mixture // momentum equation is coupled to continuity and pressure // // This approximation is valid only in the limit of small drift-velocity. // For large drift-velocity an Euler-Euler approach should be used in // which both the continuous and dispersed-phase momentum equations are // solved and coupled to the pressure. const volVectorField& Ud = mixture_.U(); return g_ - (Ud & fvc::grad(Ud)); --- .../relativeVelocityModel/relativeVelocityModel.C | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.C b/applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.C index 9abf033249..c052259149 100644 --- a/applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.C +++ b/applications/solvers/multiphase/driftFluxFoam/relativeVelocityModels/relativeVelocityModel/relativeVelocityModel.C @@ -144,7 +144,18 @@ Foam::relativeVelocityModel::~relativeVelocityModel() Foam::tmp Foam::relativeVelocityModel::acceleration() const { - const volVectorField Ud(mixture_.U() + Udm_); + // Dispersed phase velocity + // const volVectorField Ud(mixture_.U() + Udm_); + + // Use the mixture rather than the dispersed-phase velocity to approximate + // the dispersed-phase acceleration to improve stability as only the mixture + // momentum equation is coupled to continuity and pressure + // + // This approximation is valid only in the limit of small drift-velocity. + // For large drift-velocity an Euler-Euler approach should be used in + // which both the continuous and dispersed-phase momentum equations are + // solved and coupled to the pressure. + const volVectorField& Ud = mixture_.U(); return g_ - (Ud & fvc::grad(Ud)); }