Simulation of lift force

Submitted by HendrikOtto on Tue, 11/19/2013 - 15:55

Hello everybody,

i started a simulation with 3 fractions of particles of different density (800kg/m^3, 1000kg/m^3, 2000kg/m^3, ). In the CFD part, the density of the fluid is equal to 1000 kg/m^3 and nu = 1.3e-6 in a newtonian fluid.

I expected that the particles with a density of less than the density of water are swimming on the top. But all particles are sinking to the ground. Do I have to use a other force model? It is like i get no lift force. But if i set the density of a particle with the radius 1 to rho = 5kg/m^3, this particle will swim on top.

I dont understand the Simulation. Does anybody know what i'm dong wrong?

Hendrik

Forums:

HendrikOtto | Wed, 11/20/2013 - 14:22

Hey Will,
how are you? I dont know. how i can attach something...

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.4 |
| \\ / A nd | Web: http://www.openfoam.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/

FoamFile
{
version 2.0;
format ascii;

root "";
case "";
instance "";
local "";

class dictionary;
object couplingProperties;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

//===========================================================================//
// sub-models & settings

modelType B; // A or B

couplingInterval 20;

voidFractionModel divided;//centre;//bigParticle;//

locateModel engine;//standard;

meshMotionModel noMeshMotion;

regionModel allRegion;

IOModel basicIO; //trackIO; //

dataExchangeModel twoWayMPI;//twoWayFiles;//oneWayVTK;//

averagingModel dense;//dilute;//

clockModel standardClock;//off; //

smoothingModel off;

forceModels
(
DiFeliceDrag
//SchillerNaumannDrag
//KochHillDrag
//MeiLift
//virtualMassForce
Archimedes
);

momCoupleModels
(
implicitCouple
);

turbulenceModelType RASProperties;//LESProperties;//

//===========================================================================//
// sub-model properties

implicitCoupleProps
{
velFieldName "U";
granVelFieldName "Us";
voidfractionFieldName "voidfraction";
}

DiFeliceDragProps
{
velFieldName "U";
densityFieldName "rho";
voidfractionFieldName "voidfraction";
}

SchillerNaumannDragProps
{
velFieldName "U";
densityFieldName "rho";
}

KochHillDragProps
{
velFieldName "U";
densityFieldName "rho";
voidfractionFieldName "voidfraction";
}

MeiLiftProps
{
velFieldName "U";
densityFieldName "rho";
}

ArchimedesProps
{
densityFieldName "rho";
gravityFieldName "g";
treatDEM;
}

virtualMassForceProps
{
velFieldName "U";
densityFieldName "rho";
}

oneWayVTKProps
{
couplingFilename "vtk_out%4.4d.vtk";
maxNumberOfParticles 30000;
}

twoWayMPIProps
{
liggghtsPath "../DEM/in.lmp";
}

twoWayFilesProps
{
maxNumberOfParticles 10000;
DEMts 2e-6;
}

centreProps
{
alphaMin 0.30;
}

dividedProps
{
alphaMin 0.3;
scaleUpVol 1.0;
}

bigParticleProps
{
maxCellsPerParticle 1000;
alphaMin 0.30;
scaleUpVol 1.0;
}

engineProps
{
treeSearch true;
}

// ************************************************************************* //