|
[Sponsors] |
Effective thermal conductivity chtMultiRegionSimpleFoam |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
|
November 6, 2021, 04:09 |
Effective thermal conductivity chtMultiRegionSimpleFoam
|
#1 |
Senior Member
Derek Mitchell
Join Date: Mar 2014
Location: UK, Reading
Posts: 172
Rep Power: 13 |
In the standard solid energy equation betav scales the thermal diffusivity
and if betav is great than one the energy moving through the medium increases To model a porosity in fluid I use fvOptions explicitPorositySource to cater for the momentum. I modified the fluid energy equation to make it similar to the usage of betav i.e betaw in the lapacian term. This is to enable varying the effective conductivity of the fluid. But if betaw is greater than 1 the energy flow through the medium decreases. Why is this the opposite effect to the solid ????? modified solver and case file attached OpenFOAM version 4.x Modified file: UchtMultiRegionSimpleFoam/fluid/EEqn.H betaw multipler is the only modification Code:
{ volScalarField& he = thermo.he(); fvScalarMatrix EEqn ( fvm::div(phi, he) + ( he.name() == "e" ? fvc::div(phi, volScalarField("Ekp", 0.5*magSqr(U) + p/rho)) : fvc::div(phi, volScalarField("K", 0.5*magSqr(U))) ) - fvm::laplacian(betaw*turb.alphaEff(), he) == rho*(U&g) + rad.Sh(thermo) + fvOptions(rho, he) ); EEqn.relax(); fvOptions.constrain(EEqn); EEqn.solve(); fvOptions.correct(he); thermo.correct(); rad.correct(); Info<< "Min/max T:" << min(thermo.T()).value() << ' ' << max(thermo.T()).value() << endl; } Code:
{ for (int nonOrth=0; nonOrth<=nNonOrthCorr; nonOrth++) { fvScalarMatrix hEqn ( ( thermo.isotropic() ? -fvm::laplacian(betav*thermo.alpha(), h, "laplacian(alpha,h)") : -fvm::laplacian(betav*taniAlpha(), h, "laplacian(alpha,h)") ) == fvOptions(rho, h) ); hEqn.relax(); fvOptions.constrain(hEqn); hEqn.solve(); fvOptions.correct(h); } } thermo.correct(); Info<< "Min/max T:" << min(thermo.T()).value() << ' ' << max(thermo.T()).value() << endl; Code:
PtrList<volScalarField> betawFluid(fluidRegions.size()); // betawFluid mod start Info<< " Adding to betawFluid\n" << endl; IOobject betawFluidIO ( "betawFluid", runTime.timeName(), fluidRegions[i], IOobject::MUST_READ, IOobject::AUTO_WRITE ); if (betawFluidIO.headerOk()) { Info<< " reading betawFluid file \n" << endl; betawFluid.set ( i, new volScalarField(betawFluidIO, fluidRegions[i]) ); } else { Info<< " reading all betawFluid as 1.0 \n" << endl; betawFluid.set ( i, new volScalarField ( IOobject ( "betawFluid", runTime.timeName(), fluidRegions[i], IOobject::NO_READ, IOobject::NO_WRITE ), fluidRegions[i], dimensionedScalar("1", dimless, scalar(1.0)) ) ); } //betawFluid mod end Code:
const volScalarField& betaw = betawFluid[i];
__________________
A CHEERING BAND OF FRIENDLY ELVES CARRY THE CONQUERING ADVENTURER OFF INTO THE SUNSET Last edited by derekm; November 6, 2021 at 04:45. Reason: added openFOAM version |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
effective thermal conductivity and mass weighted thermal conductivity | Weiqiang Liu | FLUENT | 8 | June 19, 2020 00:08 |
Question about anisotropic thermal conductivity | Szweyk | STAR-CCM+ | 2 | June 30, 2016 08:26 |
Thermal conductivity issue | Jared1986 | CFX | 3 | March 20, 2014 10:38 |
IAPWS water properties + orthotropic thermal conductivity | Chander | CFX | 1 | February 29, 2012 17:26 |
Porous Media Effective Thermal Conductivity | Greg Perkins | FLUENT | 3 | August 5, 2001 21:53 |