[alexeym]

Hi,

Concerning your dimension problem, if you take a look at for ex. EulerDdtScheme.C, definition for fvc::ddt is

EulerDdtScheme<Type>::fvcDdt
(
    const volScalarField& rho,
    const GeometricField<Type, fvPatchField, volMesh>& vf
)
{
...
    else
    {
        return tmp<GeometricField<Type, fvPatchField, volMesh> >
        (
            new GeometricField<Type, fvPatchField, volMesh>
            (
                ddtIOobject,
                rDeltaT*(rho*vf - rho.oldTime()*vf.oldTime())
            )
        );
    }
}

in your case rho is cp, while for fvm::ddt is

template<class Type>
tmp<fvMatrix<Type> >
EulerDdtScheme<Type>::fvmDdt
(
    const volScalarField& rho,
    const GeometricField<Type, fvPatchField, volMesh>& vf
)
{
...    {
        fvm.source() = rDeltaT
            *rho.oldTime().internalField()
            *vf.oldTime().internalField()*mesh().V();
    }
...
}

Guess it's where dimensions difference comes from.

About radiation term addition:
Can't you just write it like:

cp*radiation->Sh(thermo)

as you enthalpy equation is basically temperature equation times specific heat?

[dzi]

thank you alexeym, for your hints!

Originally Posted by alexeym

Hi,


About radiation term addition:
Can't you just write it like:

cp*radiation->Sh(thermo)

as you enthalpy equation is basically temperature equation times specific heat?

-> that is also what I thought.

To test the way via another variable, in buoyantSimpleRadiationFoam i defined

Foam::fvScalarMatrix fsm_radiationSource =  radiation->Sh(thermo) ;

and in the solver hEqn.H

  fvScalarMatrix hEqn
    (
        fvm::div(phi, h)
      - fvm::Sp(fvc::div(phi), h)
      - fvm::laplacian(turbulence->alphaEff(), h)
     ==
      - fvc::div(phi, 0.5*magSqr(U), "div(phi,K)")
      + fsm_radiationSource 
    );

which works.

but when I use radiation in melt solver in similar way:

    Foam::fvScalarMatrix fsm_radiationSource =  radiation->Sh(thermo);

    fvScalarMatrix hEqn
    (
        fvm::ddt(cp, T)
      + fvm::div(phi*fvc::interpolate(cp), T)
      + hs*exp(-pow((T-Tmelt)/Tdim,2))/Foam::sqrt(constant::mathematical::pi)/Tdim*fvm::ddt(T)
      + hs*exp(-pow((T-Tmelt)/Tdim,2))/Foam::sqrt(constant::mathematical::pi)/Tdim*(U & fvc::grad(T))
      - fvm::laplacian(lambda/rho, T)
      +  cp*fsm_radiationSource
    );

it runs into this (dimension? field?) error

--> FOAM FATAL ERROR: 
incompatible fields for operation 
    [T] + [h]

    From function checkMethod(const fvMatrix<Type>&, const fvMatrix<Type>&)
    in file /opt/openfoam211/src/finiteVolume/lnInclude/fvMatrix.C at line 1303.

FOAM aborting

thanks again, i think i will try something else...

[Dostoyefsky]

Hello everyone,
I am trying to include species eqn to the enthalpy porosity solver and I want to add a loop in case of 0 < alpha < 1 (by using if statement?).
Since I am new to openfoam, I don't know how to do it.
Can somebody help me? Thanks in advance

Robert

[ahmmedshakil]

Would please write down the species equation and condition you want to impose?

[Dostoyefsky]

Well, actually I am using solver created by Mr. Fabian Roesler (convMeltFoam).
After solving the energy equation, I want to calculate the equilibrium concentration at the interface (0<alpha1<1) by using phase diagram.
Would you give me some advice please?

Regards
Robert

[ThomasV]

Hi!

I'd like to ask for advice for a solver problem of mine. I'm looking into an alloy phase change problem and ran into some problems with the energy equation. What works so far is this:

   fvScalarMatrix TEqn
    (
        sensibleH * fvm::ddt(Temp)

      + fvm::div(phiMix * fvc::interpolate(sensibleH), Temp, "div(phib*specificH,Temp)")
 
      - fvm::laplacian(lambda / rhob, Temp, "laplacian(lambda|rhob,Temp)")
        
      - Lb * deltaFracSol / oldTimestep
    );

This gives me the graph I want as can be seen here with nice primary and eutectic solidification:
graph good.jpg

The problem now is that the above simulation was done for a single cell. When doing simulations with multiple cells and convection this won't work and give strange results. So one has to use a source term just like the first to lines of code with a time derivation and a divergence. I'll leave convection aside for now and do this:

   fvScalarMatrix TEqn
    (
        sensibleH * fvm::ddt(Temp)

      + fvm::div(phiMix * fvc::interpolate(sensibleH), Temp, "div(phib*specificH,Temp)")
 
      - fvm::laplacian(lambda / rhob, Temp, "laplacian(lambda|rhob,Temp)")
        
      + Lb * deltaFracSol / temperatureChange * fvm::ddt(Temp)
    );

This unfortunately gives me this result I also had presented in an early post of mine:
Graph_Temp_alpha.jpg

Primary and eutectic solidification sort of exist but the entire recalescence aspect is gone...

I now would like to know if you have any suggestions as to what I should do or give advice as to why the second result is so different. By design both should be the same equation as one might say:



So the source term expression for both approaches should be pretty much the same or am I mistaken here? Another difference is the sign of the source term one has to add or subtract depending on which variant is used (EDIT: This is ok though as I simply defined my temperatureChange field the other way round.)...

Does anyone have an idea what is wrong with the approach with OpenFOAM's fvm::ddt(Temp) and why the temperature won't rise but stay the same?

[ahmmedshakil]

Hi,
Has anyone working with melting/solidification modelling considering temperature dependent thermo physical properties (i.e. Cp = Cp(T), K=K(T)) ?
Please give some advice how to deal with this type of problem ? I have used the source based enthalpy method as Fabian, but the problem happens when I make thermophysical properties as variable

Thanks in advance

[AnjaMiehe]

Hello Shakil,

I am so sorry, I almost forgot about you. At present, I am writing my things together for my PhD and my contract is running out, so I am bit blinkered.

For the implementation of temperature dependent thermophysical properties in general, please take a look here:
http://www.cfd-online.com/Forums/ope...ies-false.html

Then, going on from post #56, use the interpolation procedure within the do-loop. When you implement it, start with the thermophysical post and get that one to run. After that, if you go for solidification / melting with dependent properties, start with a weak dependence and build up from there.

I am going to publish my code as soon as I have my PhD ready, but that might take some months.

Best Regards, Anja

[wumin]

Anybody can help me?when I compile meltFoam with wmake command,i face a problem about compiling meltFoam:

fuguang@fuguang-Veriton-D630:~/Downloads/meltFoam_solver$ wmake
SOURCE=meltFoam.C ; g++ -m64 -Dlinux64 -DWM_DP -Wall -Wextra -Wno-unused-parameter -Wold-style-cast -Wnon-virtual-dtor -O3 -DNoRepository -ftemplate-depth-100 -I/opt/openfoam230/src/finiteVolume/lnInclude -IlnInclude -I. -I/opt/openfoam230/src/OpenFOAM/lnInclude -I/opt/openfoam230/src/OSspecific/POSIX/lnInclude -fPIC -c $SOURCE -o Make/linux64GccDPOpt/meltFoam.o
In file included from meltFoam.C:83:0:
pEqn.H: In function ‘int main(int, char**)’:
pEqn.H:8:11: error: ‘ddtPhiCorr’ is not a member of ‘Foam::fvc’
/opt/openfoam230/src/finiteVolume/lnInclude/readTimeControls.H:38:8: warning: unused variable ‘maxDeltaT’ [-Wunused-variable]
make: *** [Make/linux64GccDPOpt/meltFoam.o] Error 1

[fabian_roesler]

Hi wumin

This sounds to me like a version mismatch. Which OpenFOAM version do you use? I bet you use OpenFOAM 2.3.x since the ddtPhiCorr in pEqn was changed to a more general ddtCorr. Have a look into other pEqn of standard solvers in OF and check for differences

pEqn.H:8:11: error: ‘ddtPhiCorr’ is not a member of ‘Foam::fvc’

Regards
Fabian

[wumin]

Hi Fabian,
thanks for your reply.You are right! The version I now use is OpenFoam-2.3.0.
My work is mainly to simulate the melting and solidification of selective laser melting（3D printing）.
I want to compile the meltFoam,but always fail.Can you tell me how to deal with the problem?
the system I install is ubuntu 12.04.

[ahmmedshakil]

Hi Wumin,
Have tried with the meltFoam version provided by Fabian in post#19 (http://www.cfd-online.com/Forums/ope...g-problem.html) ?

[RaghavendraRohith]

Hi

I have been working on the melting problem for one month and more. I am using the solver from Fabian as a test bed to implement the enthalpy linearization. while in this method, it is a bit complex to implement it in OpenFOAM. Somebody has gone through this method in the past?

Best Regards
Rohith

[ahmmedshakil]

Hi RaghavendraRohith,
It sounds cool that someone also trying with the enthalpy linearization method. I'm using linearization method based on Voller's source based method i.e. linearization of the term. I have also validated my case with the gallium melting and the results are cool! But now stuck with different types of problem...

#shakil

[RaghavendraRohith]

Hi Shakil

Actually I am not asking for source based method

Please go through it, let me know your idea if so.


Regards
Rohith

[houwy]

Originally Posted by fabian_roesler

Hi all

I posted that it might take some time to review the meltFoam solver and port it from OF_1.7 to OF_2.1 but I felt like doing it instantly. So here you go . I hope you enjoy it.

Regards

Fabian

Hello! Fabian
I have some problem to wmake meltFoam on OF2.2.0. Can you help me to solve this problem. I'm a new user and I want to know if I can use this Foam to simulate a solid particle dissolution in liquid.
Thanks very much!


Making dependency list for source file meltFoam.C
SOURCE=meltFoam.C ; g++ -m64 -Dlinux64 -DWM_DP -Wall -Wextra -Wno-unused-parameter -Wold-style-cast -Wnon-virtual-dtor -O3 -DNoRepository -ftemplate-depth-100 -I/opt/openfoam220/src/finiteVolume/lnInclude -IlnInclude -I. -I/opt/openfoam220/src/OpenFOAM/lnInclude -I/opt/openfoam220/src/OSspecific/POSIX/lnInclude -fPIC -c $SOURCE -o Make/linux64GccDPOpt/meltFoam.o
/opt/openfoam220/src/finiteVolume/lnInclude/readTimeControls.H: In function ‘int main(int, char**)’:
/opt/openfoam220/src/finiteVolume/lnInclude/readTimeControls.H:38:8: warning: unused variable ‘maxDeltaT’ [-Wunused-variable]
g++ -m64 -Dlinux64 -DWM_DP -Wall -Wextra -Wno-unused-parameter -Wold-style-cast -Wnon-virtual-dtor -O3 -DNoRepository -ftemplate-depth-100 -I/opt/openfoam220/src/finiteVolume/lnInclude -IlnInclude -I. -I/opt/openfoam220/src/OpenFOAM/lnInclude -I/opt/openfoam220/src/OSspecific/POSIX/lnInclude -fPIC -Xlinker --add-needed -Xlinker --no-as-needed Make/linux64GccDPOpt/meltFoam.o -L/opt/openfoam220/platforms/linux64GccDPOpt/lib \
-lfiniteVolume -lOpenFOAM -ldl -lm -o /home/hwy/OpenFOAM/hwy-2.2.0/platforms/linux64GccDPOpt/bin/meltFoam

[houwy]

hello! Have your problem been solved?

[RaghavendraRohith]

Originally Posted by houwy

hello! Have your problem been solved?

Hello Houwy

This is not fabian, but i can help you in this aspect

I do not see what actually is your problem, the solver is compiled now and may be you can simulate your case, yes meltFoam is a solver to solve melting of a solid particle or a solid body.

Go forward with your simulation once

Regards
Rohith

[AnjaMiehe]

Hello everyone,

here is Fabians convMeltFoam solver of post #81 for you compiling in OpenFOAM 2.3.0 with the test case, as one boundary condition for the pressure changed its name. Have fun using it.

Regards, Anja

[zhouzhipeng77]

Originally Posted by fabian_roesler

Hi all

I posted that it might take some time to review the meltFoam solver and port it from OF_1.7 to OF_2.1 but I felt like doing it instantly. So here you go . I hope you enjoy it.

Regards

Fabian

Hello,
Fabian.Thank you for your solver about melting.But I have some questions with your solver. In the UEqn.H , you use a symbol "DC" calculated form DCl,DCs and alpha. Can you explain what are their meanings ? And can you give me your mathematical model?