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September 1, 2011, 20:52 
rhoCentralFoam Solver

#1 
Member
venkat
Join Date: Mar 2011
Location: Bangalore,india
Posts: 47
Rep Power: 7 
Dear Foamers,
I am unable to understand the code given in the RhoCentralFoam.C i mean the working procedure, but in the user guide given about pisoFoam and IcoFoam. Where should I find the information about the code like " reconstruct(rho)" thanks in advance. 

September 6, 2011, 22:06 

#2 
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,907
Rep Power: 27 
There is a paper on the solver:
Christopher J. Greenshields, Henry G. Weller, Luca Gasparini and Jason M. Reese, Implementation of semidiscrete, nonstaggered central schemes in a colocated, polyhedral, ﬁnite volume framework, for highspeed viscous ﬂows, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Int. J. Numer. Meth. Fluids 2010; 63:1–21 For the definition of reconstruct: ~/OpenFOAM/OpenFOAM2.0.x/src/finiteVolume/finiteVolume/fvc/ I hope this helps.
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Alberto Passalacqua GeekoCFD  A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats. OpenQBMM  An opensource implementation of quadraturebased moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using. 

September 7, 2011, 02:16 

#3 
Member
venkat
Join Date: Mar 2011
Location: Bangalore,india
Posts: 47
Rep Power: 7 
Dear Alberto Passalacqua thank you very much for your kind information
Regards, 

April 8, 2012, 06:06 

#4 
New Member
wangwei
Join Date: Apr 2012
Posts: 9
Rep Power: 6 
Hi alberto,
I want to know that rhoCentralFoam is a steady solver or a transient solver?Thank you 

April 8, 2012, 16:49 

#5 
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,907
Rep Power: 27 
It is a transient solver. You can check that easily by looking at the tutorials.
__________________
Alberto Passalacqua GeekoCFD  A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats. OpenQBMM  An opensource implementation of quadraturebased moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using. 

April 9, 2012, 14:54 
hi

#6 
Member
nsreddy
Join Date: Sep 2010
Posts: 33
Rep Power: 7 
There are two types of solvers in openFoam for compressible flows. For example RhoSimpleFoam and RhoCentralFoam. The solution methods (algorithm) are different for the above two solvers. How to choose the solver. And what are all the parameters we have to consider while selecting the solvers.
Regards, 

April 9, 2012, 17:10 

#7  
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,907
Rep Power: 27 
Quote:
The rhoCentralFoam solver uses a densitybased approach with central schemes, and it solves the unsteady equations. The choice of the solver depends on the type of flow you have:  Steady/unsteady?  High Mach number (density based approach) / low Mach number (pressurebased approach)? Best,
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Alberto Passalacqua GeekoCFD  A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats. OpenQBMM  An opensource implementation of quadraturebased moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using. 

April 10, 2012, 00:10 
hi

#8 
Member
nsreddy
Join Date: Sep 2010
Posts: 33
Rep Power: 7 
hi alberto,
Thanks for reply, How to find the which solver is the best for different range of Mach Numbers, and is there any limitation for any solver for prescribed Mach Mumber, How to find that. How the results are varies if i use pressure based solvers and density based solvers if i use same problem. what are all the factors we have to consider. Regards, 

April 10, 2012, 20:02 

#9  
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,907
Rep Power: 27 
Quote:
If you have a specific problem in mind, you should provide details about it, so that the question is specific.
__________________
Alberto Passalacqua GeekoCFD  A free distribution based on openSUSE 64 bit with CFD tools, including OpenFOAM. Available as in both physical and virtual formats. OpenQBMM  An opensource implementation of quadraturebased moment methods. To obtain more accurate answers, please specify the version of OpenFOAM you are using. 

April 19, 2012, 08:19 

#10  
Member
Alexander
Join Date: Mar 2009
Posts: 41
Rep Power: 9 
Quote:
I am using rhoCentralFoam for my transsonic laminar problem. May be I am wrong, but the one of the main feature of rhoCentralFoam I think is using of fully conservative scheme, so the main conservative laws (for example, for energy) are always preserved. I tried sonicFoam and rhoSimpleFoam and found that there were problems with temperature distributions (such problems were discussed on the forum). As for rhoPimpleFoam I cannot get it worked for my case =( So I recommend use of rhoCentralFoam for the problems with Mach number > ~1 

August 26, 2013, 11:29 

#11 
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,209
Rep Power: 18 
Hi
what does the lines for momentum solving in this solver mean? Code:
//  Solve momentum solve(fvm::ddt(rhoU) + fvc::div(phiUp)); U.dimensionedInternalField() = rhoU.dimensionedInternalField() /rho.dimensionedInternalField(); U.correctBoundaryConditions(); rhoU.boundaryField() = rho.boundaryField()*U.boundaryField(); volScalarField rhoBydt(rho/runTime.deltaT()); if (!inviscid) { solve ( fvm::ddt(rho, U)  fvc::ddt(rho, U)  fvm::laplacian(muEff, U)  fvc::div(tauMC) ); rhoU = rho*U; } Code:
fvm::ddt(rho, U)  fvc::ddt(rho, U)  fvm::laplacian(muEff, U)  fvc::div(tauMC)
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