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Multiphase flow and Phase change due to heat transferevaporation 

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August 6, 2009, 07:48 

#61 
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Rachel Vogl
Join Date: Jun 2009
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@Hamed : If you are upgrading to OpenSUSE 11.1 for OF1.6 it is not necessary. I am using SLED 10 till now. paraFoam does not work...
@ Sandy: I could not find interPhaseChangeFoam tutorial in OF1.6 

August 13, 2009, 09:47 

#62 
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Rachel Vogl
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Anybody managed to get rhoReactingFoam working ?
I am still having problems with this solver... as mentioned in this thread. rhoReactingFoam 

August 23, 2009, 05:10 

#63 
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J. Cai
Join Date: Apr 2009
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Hi, guys, how about your progresses on the two phase flow simulation? I am trying to use OpenFOAM to simulate the two phase flow with condensation (vapor to water). I think it is difficult, but very interesting.
Best regards, Chiven 

September 24, 2009, 06:24 

#64 
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Sanjib Das Sharma
Join Date: May 2009
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Hi Matvej,
I am new to OpenFoam. Having started with the basics 2 months ago, I am now stuck with modeling of steadystate, liquidphase, multispecies transport with chemical reaction. Can you provide some input as to how I proceed i.e., which modules should I use. As far as I understood, I compiled with the following: simpleFoam solver + basicMixture.H + basicThermo.H + liquidMixture.H + liquid.H + pEqn.H + UEqn.H I have tried to use YEqn.H, but gave error. How to combine this and proceed ? It will be great if you have any example. Regards, Sanjib 

September 25, 2009, 12:15 

#65 
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isabel
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I have a doubt about interPhaseChangeFoam.
The momentum equation is: fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U)  fvm::Sp(fvc::ddt(rho) + fvc::div(rhoPhi), U)  fvm::laplacian(muf, U)  (fvc::grad(U) & fvc::grad(muf)) ); UEqn.relax(); if (momentumPredictor) { solve ( UEqn == fvc::reconstruct ( ( fvc::interpolate(interface.sigmaK())*fvc::snGrad(g amma)  ghf*fvc::snGrad(rho)  fvc::snGrad(pd) ) * mesh.magSf() ) ); } Why the red line is ghf*fvc::snGrad(rho) ??? I think it would be ghf*rho 

September 26, 2009, 21:10 

#66 
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Sandy Lee
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Hi isabel,
Do you understand the blue line?? How to derive it? fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U)  fvm::Sp(fvc::ddt(rho) + fvc::div(rhoPhi), U)  fvm::laplacian(muf, U)  (fvc::grad(U) & fvc::grad(muf)) ); UEqn.relax(); Thanks. 

September 27, 2009, 03:28 

#67 
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isabel
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I don't know. For me fvc::ddt(rho) + fvc::div(rhoPhi) is the continuity equation, which is equal to zero.
In interFoam (a similar solver), you don't have this blue line: fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(rhoPhi, U)  fvm::laplacian(muf, U)  (fvc::grad(U) & fvc::grad(muf)) ); if (momentumPredictor) { solve ( UEqn == fvc::reconstruct ( ( fvc::interpolate(interface.sigmaK())*fvc::snGrad(g amma)  ghf*fvc::snGrad(rho)  fvc::snGrad(pd) ) * mesh.magSf() ) ); But I still don't know why the term ghf*rho doesn't appear and what the term snGgrad(rho) means. Last edited by isabel; September 27, 2009 at 03:46. 

September 28, 2009, 16:07 

#68 
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Lakshman
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@isabel
snGrad(rho) calculates the normal component of gradient to a surface. Momentum equation in differential form requires 'rho*g' in right hand side. So to get that 'ghf'{g*hf} is multiplied by snGrad(rho). 

September 29, 2009, 03:58 

#69 
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isabel
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Thanks lucky. But I still think that I don't need grad(rho), so I have modified the UEqn.H as follows. Is this way wrong???
surfaceScalarField muf = twoPhaseProperties.muf(); volVectorField gravityterm = rho*vector(0, 9.81, 0); // this means rho*g fvVectorMatrix UEqn ( fvm::ddt(rhoU) + fvm::div(rhoPhi, U)  fvm::laplacian(muf, U)  (fvc::grad(U) & fvc::grad(nuf))  gravityterm ); UEqn.relax(); if (momentumPredictor) { solve ( UEqn == fvc::reconstruct ( fvc::interpolate(interface.sigmaK())*fvc::snGrad(g amma)  fvc::snGrad(pd) ) * mesh.magSf() ); } 

September 30, 2009, 09:28 

#70 
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isabel
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I already know why the term fvc::snGrad(rho) appears. It is a consequence of the UEqn equation works with dynamic pressure (pd) instead total pressure (p).
But I still have a question: What is the advantage of working with dynamic pressure (pd) instead total pressure (p) 

November 13, 2009, 10:02 
compressibe phase change modelling by rhoReactingFoam

#71 
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Hamed Aghajani
Join Date: Mar 2009
Location: London, UK
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Hi Rachel,
Have you got new experiences with rhoReactingFoam, to simulate phase change of a liquid into another medium? Have you find out sth from counterFlowFlame2D? Please keep us posted, Hamed 

November 13, 2009, 12:51 
Questions on cavitatingPimpleFoam

#72  
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Hamed Aghajani
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Quote:
In cavitatingPimpleFoam/pEqn, Line 17, phid2 = fvc::interpolate(psi) * (phid1 + fvc::ddtPhiCorr(rUA, rho, U, phi) / fvc::interpolate(rho)), the two sides of "+" are inconsistent because of red bold part. Am I right? Regarding the thermodynamicProperties, beside the items indicated in rascavitatingfoam tutorial, there should be some data for following parameters, according the chosen gammaModel, say Kunz; CgammaP [0 0 0 0 0] CgammaA [0 0 0 0 0] UInf [0 1 1 0 0] ? tauInf [0 0 1 0 0] ? pCoeff1 [0 0 0 0 0] ? CgammaEff [0 0 0 0 0] ? Would you please drop a line on their Initiation, values. I am facing some other incompatible dimension errors, which may share with you here, later. Best regards, Hamed 

November 13, 2009, 22:06 

#73 
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Sandy Lee
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Hi hamed, you think, what is the difference between the interPhaseChangeFoam solver with the cavitatingPimpleFoam solver? Thanks.


November 16, 2009, 08:01 
interphaseChangeFoam vs. cavitatingPimpleFoam

#74 
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Hamed Aghajani
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Sandy,
As far as I have understood, cavitatingPimpleFoam is a Homogenous cavitation solver which uses PISOSIMPLE coupling loop. Homogeneous might means there is no slip velocity between liquid and its cavitated phase. It is compressible, so uses a barotropic EOS, to deal with density. It solves for one phase wich might result in two phase [first phase + vapour/liquid of first Phase] On the other hand, interPhaseChangeFoam considers the Phase change of, say a liquid as water, into another phase, say Air. so at the end we may have two phases, (liquid and [vapour of that liquid + Air]). and the solver is incompressible here. Hope it would be a step forward, Best regards, Hamed 

January 25, 2010, 09:19 

#75 
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Matthias Voß
Join Date: Mar 2009
Location: Berlin, Germany
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hello,
i was pretty happy to find these post. since i´m trying to understand the rasCavtiationsolver in OF1.5. Like usual, i was trying to read through the code and got stuck while reading the rhoEqn.H. I think my question is: what is this phiv doing? It is some sort of correction? I read phiv=phi/fvc::interpolate(rho) but i didn´t got the grasp. I found two parts for correction in pEqn.H: resetphiPatches and resetphivpatches... but i have no clou what they are doing. Could somebody please be so kind and give me a hint? Thanks in advance, neewbie Last edited by mvoss; January 26, 2010 at 07:29. 

April 8, 2010, 06:44 
Moment method

#76 
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john
Join Date: Apr 2010
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Hi,
Does any body used moment method for aerosol coagulation of size less then 0.1 um in Fluent?. Does any know about moment method UDF?. Please let me know Thanks 

April 9, 2010, 02:09 

#77 
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matej forman
Join Date: Mar 2009
Location: Brno, Czech Republic
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John, sending the same question to this forum as well as to Fluent one is not a good thing. This forum is for OpenFOAM. It will make people annoyed, not attracted to answer your question.
good luck matej 

May 25, 2010, 04:30 
interPhaseChangeFoam tuterial

#78 
Senior Member

hi openFoam former
im going to work on evaporation of incompressible flow, can any body send me a simple model which can work properly with openFoam 1.6 solver (interPhaseChangeFoam) ? nimasam65@gmail.com 

May 25, 2010, 08:08 

#79 
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Sandy Lee
Join Date: Mar 2009
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No, I guess interPhaseChangeFoam is not suiltable to your problem, because its mode is about the specified cavitation flows, and they are some empirical formula to defined the phase change, but not really solve equations of the heat and mass transfer. Moreover, this phase change is an isothermal process.
If you need the tutorial about this solver, you can find it in OF 1.6.x 

May 28, 2010, 08:43 

#80 
Senior Member

thanks sandy
is there any solver in openFoam which is appropriate for my simulation? if no , whats ur suggestion for further progress? i dont know use whether interfoam (direct model) or bubbleFoam (Eulerian _Eulerian model) or interChangePhaseFoam as a basic solver and then add mass and heat transfers equation. could you give me some hints thanks 

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