
[Sponsors] 
June 14, 2008, 19:09 
The yEqn.H files goes like thi

#1 
New Member
Arun Shourie
Join Date: Mar 2009
Location: Singapore
Posts: 12
Rep Power: 10 
The yEqn.H files goes like this....
start of the yEqn.H file ################################################## ######### tmp<fv::convectionscheme<scalar> > mvConvection ( fv::convectionScheme<scalar>::New ( ........ ) ); { label inertIndex = 1; volScalarField Yt = 0.0*Y[0]; for(label i=0; i<Y.size(); i++) { if (Y[i].name() != inertSpecie) { volScalarField& Yi = Y[i]; solve ( fvm::ddt(rho, Yi) + mvConvection>fvmDiv(phi, Yi)  fvm::laplacian(turbulence>muEff(), Yi) == kappa*chemistry.RR(i), mesh.solver("Yi") ); Yi.max(0.0); Yt += Yi; } else { inertIndex = i; } } Y[inertIndex] = scalar(1)  Yt; Y[inertIndex].max(0.0); } ################################################## ###### End of file yEqn.H My question is what is the mathematical equation or expression for the yEqn..... Is it, as follows.... please correct me if wrong. d(rho,Yi)/dt + d(rho*u*Yi)/dx + d2(mu*Yi)dx2 = ??? (obviously, have written for the xcomponent) I could guess the left hand side of the equation.... But i couldn't understand the right hand side of the equation... Or to put my question in the other way, what are the terms "kappa*chemistry.RR(i), mesh.solver("Yi")" Help needed. Explain in a way, such that, whomsoever is new to openfoam can and I am new to foam..... 

June 15, 2008, 00:11 
Hi
Which combustion solver

#2 
Member
srinath
Join Date: Mar 2009
Location: Champaign, USA
Posts: 90
Rep Power: 10 
Hi
Which combustion solver are you referring to?reactingFoam? In icoFoam, u have a similar expression, in the PISO loop Ueqn.H() gives the nondiagonal + source terms of the matrix, but doesn't invlove the grad p term. Here is a good reference for PISO in icoFoam, which u may find useful. http://www.tfd.chalmers.se/~hani/kur...7/rhiechow.pdf Do you have a reference for reactingFoam, trying to figure out the algo without a reference is very hard. Cheers Srinath 

June 15, 2008, 05:32 
I dont have any reference as s

#3 
New Member
Arun Shourie
Join Date: Mar 2009
Location: Singapore
Posts: 12
Rep Power: 10 
I dont have any reference as such for the solver reactingFoam... someone please


June 15, 2008, 14:36 
Since this equation is species

#4 
New Member
KaLee_Kun
Join Date: Mar 2009
Location: Mumbai, India
Posts: 7
Rep Power: 10 
Since this equation is species conservation equation, the right hand side must be the source term, that is, rate of production or consumption of the species. I have looked up for the fucnction chemistry.RR > it was stated as the chemical source term.
But I am not sure about the variable 'kappa' and the function, mesh.solver("Yi") I guess someone should help him further 

June 15, 2008, 15:31 
As you can see the (laminar) c

#5 
Member
Ville Tossavainen
Join Date: Mar 2009
Posts: 60
Rep Power: 10 
As you can see the (laminar) chemical source term is multiplied by "kappa". This is a correction for turbulent reactive flows.
Next check out "chemistry.H" file and you can see how "kappa" is calculated. If the turbulence correction is not taken into account, "kappa" is set to "1.0". I don't have a reference for the Chalmers PaSR model, but maybe there's someone else who can help you. 

August 17, 2010, 13:33 

#6 
Member
Seyyed Ali H.M.
Join Date: Nov 2009
Location: Utah
Posts: 99
Rep Power: 9 
HI everyone,
I have a question . In the Yeqn equation, for diffusion of Yi, the coefficient used is Mu, why is that Mu? Why it's not D ( binary mass diffusion coefficient) ? Can anybody give a reference for this?
__________________
SAHM 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Doubt  Rishikesh  FLUENT  0  February 24, 2009 04:32 
doubt in B.C  student  Main CFD Forum  5  November 23, 2008 03:40 
Doubt  New User  FLUENT  2  July 11, 2008 23:50 
A doubt  Alberto Passalacqua (Alberto)  OpenFOAM PreProcessing  5  November 28, 2006 10:22 
a doubt  G.Balakrishnan  FLUENT  0  November 27, 2000 02:48 