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-   -   Solidification in OpenFoam (http://www.cfd-online.com/Forums/openfoam/64057-solidification-openfoam.html)

 luke.christ April 28, 2009 04:49

Solidification in OpenFoam

Dear all,

I'm going to use OpenFoam for simulating a continuous casting problem. I'm completely new to OpenFoam, and it seems to me that there is not any solidification model in OpenFoam. Should I create solidification model myself?

As my case is continuous casting, I should consider a pull velocity for solid phase, too. Is it possible without great difficulties in OpenFoam?

I will be thankful for you reply.

 hawkeye321 January 30, 2013 02:38

Are you still interested in solidification in OpenFOAM?

 Mac007 May 3, 2013 10:25

Hello

I'm newbie with OpenFOAM, but I'm interested to model solidification of steel. If i have well understood, there is no built-in solver? Do you know where I can find one?

Regards

 fabian_roesler May 3, 2013 11:00

solidification problem

Hi

In the thread http://www.cfd-online.com/Forums/ope...g-problem.html you can find several solvers for melting and solidification using the enthalpy method and the enthalpy porosity method.

Regards

Fabian

 Mac007 May 6, 2013 01:45

Thanks a lot

 einatlev June 9, 2013 16:02

Explanation for terms in TEqn.H?

Hello all!
I am trying to use meltFOAM for my project on solidification of lavas. I am trying to understand the terms appearing in TEqn.H. I identified the dT/dt, advection and diffusion terms, and then see terms that involve latent heat, and what I figure is some sort of a melt fraction term, but I don't understand the details -- what is the exponent, where did all the "4" factors come from, etc.?
Here's the code:

fvScalarMatrix TEqn
(
fvm::ddt(cp, T)
+ fvm::div(phi*fvc::interpolate(cp), T)
+ hs*4.0*exp(-pow(4.0*(T-Tmelt)/(Tl-Ts),2))/Foam::sqrt(pi)/(Tl-Ts)*fvm::ddt(T)
- fvm::laplacian(lambda/rho, T)
);

Thanks!!!

 fabian_roesler June 11, 2013 08:58

Have a look into my paper on the solver:

F. Rösler, D. Brüggemann (2011): Shell-and-tube type latent heat thermal energy storage: numerical analysis and comparison with experiments. Heat and Mass Transfer, Vol. 47 Issue 8 , 1027-1033, DOI: 10.1007/s00231-011-0866-9

Keep in mind that the solver does not account for non-linearity like the linear source method by Voller. The erfMeltSolver just reduces the non-linearity effects in the energy conservation equation. For simple problems, the results converge with a very small error for the energy conservation. With increasing convective transport, the error increases and some iteration to account for the non-linearity have to be performed.
In my previous work, I use a linear liquid fraction function and the linear source method proposed by Voller.

Regards

Fabian

 einatlev June 11, 2013 11:15

Excellent paper Fabian! Thanks for pointing it. Just what I needed.

 dinesh July 6, 2013 02:24

Stefan problem

Sir
i am also trying to analysize the phase change problem.I want to know is it possible to do it on Fluent and if yes which solver /model i should go for.
thanks

Quote:
 Originally Posted by fabian_roesler (Post 433376) Have a look into my paper on the solver: F. Rösler, D. Brüggemann (2011): Shell-and-tube type latent heat thermal energy storage: numerical analysis and comparison with experiments. Heat and Mass Transfer, Vol. 47 Issue 8 , 1027-1033, DOI: 10.1007/s00231-011-0866-9 http://www.springerlink.com/content/b1tp01k2u7q8j432/ Keep in mind that the solver does not account for non-linearity like the linear source method by Voller. The erfMeltSolver just reduces the non-linearity effects in the energy conservation equation. For simple problems, the results converge with a very small error for the energy conservation. With increasing convective transport, the error increases and some iteration to account for the non-linearity have to be performed. In my previous work, I use a linear liquid fraction function and the linear source method proposed by Voller. Regards Fabian

 fabian_roesler July 10, 2013 04:38

Hi dinesh

Yes, Fluent offers an Enthalpy-Porosity-Method for simulation of solid/liquid phase change. Unfortunately I never used Fluent for such simulations so go on and find out yourself. Good luck.

Regards

Fabian

 r.mojtaba July 20, 2013 11:59

Quote:
 Originally Posted by dinesh (Post 438078) Sir i am also trying to analysize the phase change problem.I want to know is it possible to do it on Fluent and if yes which solver /model i should go for. thanks
Hello danish.

As Fabian said, FLUENT can solve Solidification/Melting problems. I myself tested and validated the solver for my thesis. There are excellent tutorial and theory materials from Ansys Fluent. Using Google, you may find them with no problem.

Have fun!

 dinesh August 30, 2013 05:18

Quote:
 Originally Posted by r.mojtaba (Post 440966) Hello danish. As Fabian said, FLUENT can solve Solidification/Melting problems. I myself tested and validated the solver for my thesis. There are excellent tutorial and theory materials from Ansys Fluent. Using Google, you may find them with no problem. Have fun!
I found from literature but there is contradiction.
Ref "H. Shmueli et al. / International Journal of Heat and Mass Transfer 53 (2010) 4082–4091" this paper says "page number 4086 says: As for the pressure discretization, only PRESTO!and Body-Force-Weighted schemes are available for the VOF and mixture multiphase models." Does this means that multiphase has to be used for my case. Enabling this i find that courant number can be inserted which the paper says to be kept around 0.5. what about the phase 1 and phase 2. see this post by me which flotus replied on 11july
Ref "http://www.cfd-online.com/Forums/system-analysis/120322-stefan-problem.html#post439934"

 r.mojtaba August 30, 2013 21:59

Quote:
 Originally Posted by dinesh (Post 448858) see this post by me which flotus replied on 11july Ref "http://www.cfd-online.com/Forums/system-analysis/120322-stefan-problem.html#post439934"
So you have two zones, one is a closed container with PCM solidification and the other with a fluid flow around container, Right? If so, you don't need multiphase model at all. Using Fluent, during the solidification there is only one phase (fluid). To model solid zone (which is not really a solid phase in this model), Fluent adds a huge artificial viscosity to the solid zone to prevent flow on it. In this way, there is no need to define two phase flow.

A Numerical Study on Time-Dependent Melting and Deformation Processes of Phase Change Material (PCM) Induced by Localized Thermal Input

 dinesh September 1, 2013 08:34

Quote:
 Originally Posted by r.mojtaba (Post 448985) So you have two zones, one is a closed container with PCM solidification and the other with a fluid flow around container, Right? If so, you don't need multiphase model at all. Using Fluent, during the solidification there is only one phase (fluid). To model solid zone (which is not really a solid phase in this model), Fluent adds a huge artificial viscosity to the solid zone to prevent flow on it. In this way, there is no need to define two phase flow. I think this open access paper can help you: A Numerical Study on Time-Dependent Melting and Deformation Processes of Phase Change Material (PCM) Induced by Localized Thermal Input
I went through this paper it refers on page no 529 TO REPRESENT THE FREE SURFACE OF THE MELTING REGION ADJACENT TO THE GAS PHASE, VOF METHOD IS USED. Now in fluent this VOF is under the menu of multiphase model. so plz clarify me? how can i find the melted region profile?

 r.mojtaba September 3, 2013 01:30

You didn't answer my question about whether the solidification zone is a fully filled container or not? If there is no gas in contact, using VOF is not necessary at all.
When you plot the contour of liquid fraction (F) the melt-solid (or melt-gas) interface can obviously be seen and extract. Refer to Kim's paper, Fig. 9 to 11.

 dinesh September 3, 2013 02:53

Quote:
 Originally Posted by r.mojtaba (Post 449475) You didn't answer my question about whether the solidification zone is a fully filled container or not? If there is no gas in contact, using VOF is not necessary at all. When you plot the contour of liquid fraction (F) the melt-solid (or melt-gas) interface can obviously be seen and extract. Refer to Kim's paper, Fig. 9 to 11.
I am handling without air case.
Plz see the plot i got
https://www.dropbox.com/s/gg3mqyum1u3mx5z/frac4000s.png
How can i extract the data regarding the anount or percent of solid melted/or mushy zone volume.
thanks

 r.mojtaba September 3, 2013 11:15

Quote:
 Originally Posted by dinesh (Post 449485) How can i extract the data regarding the amount or percent of solid melted/or mushy zone volume.
You need to calculate volume integral of liquid fraction. Fluent can do this by some simple Clicks. Do as below:
-From Menu Bar, go to Report and choose Volume Integrals... to open Volume Integral Window.
-In Volume Integrals Window:
--Choose Fluid (or whatever the solidification zone's name is) from right menu (Cell Zones),
--Choose Volume Integral from left menu (Report Type),
--Under Field Variable, select Solidification/Melting... and then Liquid Fraction,
--Click Compute button... and it's done!
Good Luck

 dinesh September 4, 2013 08:56

Quote:
 Originally Posted by r.mojtaba (Post 449585) You need to calculate volume integral of liquid fraction. Fluent can do this by some simple Clicks. Do as below: -From Menu Bar, go to Report and choose Volume Integrals... to open Volume Integral Window. -In Volume Integrals Window: --Choose Fluid (or whatever the solidification zone's name is) from right menu (Cell Zones), --Choose Volume Integral from left menu (Report Type), --Under Field Variable, select Solidification/Melting... and then Liquid Fraction, --Click Compute button... and it's done! Good Luck
thankyou very much for the support you provided.
Can you plz tell me about the discretization method. I used SIMPLE method with PRESTO scheme (without gravity being aplied) i got some result. Now i am using PISO with Body Force weighted with gravity added slowly from 1m/s2 to 9.81 m/s2 (as recommended by some user). I run the simulation for some time and then i get divergence either in epsilon or( x y z componenet of velocity) can you suggest some way to overcome this.

 r.mojtaba September 4, 2013 10:01

What are Ra and Pr numbers related to your simulation?

I've done an unsteady simulation of melting Gallium in a 2D cavity with Ra=2.2x10^5. I used SIMPLE for pressure-velocity coupling, PRESTO! for pressure discretization and SST k-w for turbulence modeling. You can obtain a good convergence with a small enough time step and fine enough grid.