CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Figuring out how mu_eff and alphaeff are calcualted for reactingFoam

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By kuria

 
 
LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
Old   June 22, 2021, 09:48
Default Figuring out how mu_eff and alphaeff are calcualted for reactingFoam
  #1
Member
 
K
Join Date: Mar 2018
Posts: 34
Rep Power: 8
kuria is on a distinguished road
Hey Foamers

I am looking at the reactingFoam solver in OpenFOAM 8 and trying to understand how the energy and species equations are solved.

In energy equation:
fvScalarMatrix EEqn
(
fvm::ddt(rho, he) + mvConvection->fvmDiv(phi, he)
+ fvc::ddt(rho, K) + fvc::div(phi, K)
+ (
he.name() == "e"
? fvc::div
(
fvc::absolute(phi/fvc::interpolate(rho), U),
p,
"div(phiv,p)"
)
: -dpdt
)
+ thermophysicalTransport->divq(he)
==
reaction->Qdot()
+ fvOptions(rho, he)
);

EEqn.relax();

fvOptions.constrain(EEqn);

EEqn.solve();

thermophysicalTransport->divq(he) is calculated for the turbulent part as
template<class TurbulenceThermophysicalTransportModel>
tmp<fvScalarMatrix>
eddyDiffusivity<TurbulenceThermophysicalTransportM odel>::divq
(
volScalarField& he
) const
{
return -fvm::laplacian(this->alpha()*this->alphaEff(), he);
}


Similarly for species transport equation, the laplacian term is calcualted based on
template<class TurbulenceThermophysicalTransportModel>
tmp<fvScalarMatrix>
eddyDiffusivity<TurbulenceThermophysicalTransportM odel>::divj
(
volScalarField& Yi
) const
{
return -fvm::laplacian(this->alpha()*this->DEff(Yi), Yi);
}


I understood until here, but I could not figure out how both DEff and alphaEff are calculated.

Has someone looked into how these are calculated ?
kuria is offline   Reply With Quote

 


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 08:02.