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Old   September 25, 2017, 13:02
Question
  #101
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Elham
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Quote:
Originally Posted by nimasam View Post
Dear Elham
Please re-read my points, you will figure out how it is derived.
equation 18:

lets consider S=-mDot(1/rho1-alpha1(1/rho1-1/rho2)))
then source terms for boiling and condensations would be:
Sb=S*alpha1
Sc=S*(1-alpha1)
Also i mentioned in previous post that:

then right hand side of equation 18 becomes:

so alpha1*div(U) is appearing here
now consider boiling and condensation separately,
for boiling the source term is Sb=S*alpha1
so

for condensation Sb=S*(1.0-alpha1), then:
Sorry but I am still confused.

Base on

Quote:
ddt(alpha1)+div(U,alpha1)+Sp*alpha1+Su=0
For boiling it should be :

Quote:
Sp=- div(U) and Su= -S
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Old   September 25, 2017, 13:50
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i said Sb=S*alpha1, if you consider Su=S, then you missed alpha1 in equation.
about negative signs, it is better to refer the code to see the exact formulation of MULES, i may missed the signs in post
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Old   September 26, 2017, 11:11
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Quote:
Originally Posted by nimasam View Post

i said Sb=S*alpha1, if you consider Su=S, then you missed alpha1 in equation.
about negative signs, it is better to refer the code to see the exact formulation of MULES, i may missed the signs in post
Dear Nima,

Thanks for all kind answers. I got the idea.You have separated the general source term into two parts; condensation and boiling so that S=Sb+Sc. Then for the boiling phase you just have Sb as source term and for condensation just Sc.

Cheers,

Elham
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Old   November 4, 2017, 15:35
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  #104
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Cláudio Corrêa
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Quote:
Originally Posted by nimasam View Post
i have developed a solver based on interFOAM, to solve energy equation and besides consider mass transfer between two phases, this solver works correctly for one dimensional case (stephan phase change problem)
but for two case studies, temperature at interface behaves strangely
now any suggestion, cooperation or idea will be helpful

P.S
developed files and case studies are available in attachment
+
some descriptions can be found here:

http://www.4shared.com/document/-eBG...OF_method.html
Hi nimasam
I'm interested in this problem too. I have trying to solve the problem of water vapor condensation in vertical pipe. My problem is three-dimensional. Could you help me solve this problem? I'm used OpenFoam 4.1
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Old   November 5, 2017, 07:21
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Dear Cláudio Corrêaread this post, i upload a solver based on OpenFOAM_2.2.0 which considers both evaporation and condensation and it is suitable for your work
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Old   December 6, 2017, 01:42
Default constructor classes
  #106
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Dear Nima,

I am wondering why you defined two different word classes, word& type and word& alpha1Name in phaseChangeHeatFoam?

In constructor of phaseChangeTwoPhaseMixture.C you have:

Foam:haseChangeTwoPhaseMixture:haseChangeTwoPh aseMixture
(
const word& type,
const volVectorField& U,
const surfaceScalarField& phi,
const word& alpha1Name
)

I would appreciate if you let me know.

Cheers,

Elham
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Old   February 14, 2018, 04:28
Default anonymous term in energy equation
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Dear Niam,

Regarding to phaseChangeHeatFoam the energy equation (25) in your paper is :

ddT + div (UT) - lapplacian (k/rhoC, T) = -1/rhoC *mdotTriplePrime*Hlg

there is a term in TEqn.H in line 19

Code:
- fvm::Sp(fvc::div(phi),T)
which is not corresponding to any term in energy equation.


The whole left side of TEqn is as following:
Code:
    fvScalarMatrix TEqn
    (
          fvm::ddt(T)
        + fvm::div(phi, T)
        - fvm::Sp(fvc::div(phi),T)
        - Foam::fvm::laplacian( k/rhoC_ , T,"laplacian(alphaEff,T)")
    /*    + (
            fvc::div(fvc::absolute(phi, U), p)
          + fvc::ddt(rho, KE) + fvc::div(rhoPhi, KE)
          )/rhoC
    */
    );
Would you please explain a bout it?

Regards,

Elham
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Old   February 14, 2018, 06:27
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Hi Nima Sam.

Could you kindly send me your solver to the email ID saicharanb56@gmail.com ? I would really appreciate it.

I am trying to simulate sessile droplet evaporation and I believe your solver will be ideal for me. I am, however, new to OpenFOAM and do not possess enough skill to code my own solver.

Thanks in advance.
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Old   February 20, 2018, 02:10
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Nima Samkhaniani
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Dear Saicharan

please look this post
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Old   February 25, 2018, 13:22
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Quote:
Originally Posted by Elham View Post
Dear Niam,

Regarding to phaseChangeHeatFoam the energy equation (25) in your paper is :

ddT + div (UT) - lapplacian (k/rhoC, T) = -1/rhoC *mdotTriplePrime*Hlg

there is a term in TEqn.H in line 19

Code:
- fvm::Sp(fvc::div(phi),T)
which is not corresponding to any term in energy equation.


The whole left side of TEqn is as following:
Code:
    fvScalarMatrix TEqn
    (
          fvm::ddt(T)
        + fvm::div(phi, T)
        - fvm::Sp(fvc::div(phi),T)
        - Foam::fvm::laplacian( k/rhoC_ , T,"laplacian(alphaEff,T)")
    /*    + (
            fvc::div(fvc::absolute(phi, U), p)
          + fvc::ddt(rho, KE) + fvc::div(rhoPhi, KE)
          )/rhoC
    */
    );
Would you please explain a bout it?

Regards,

Elham
fvc::div(phi)=0, so theoretically it is zero, but numerically it is not, and it help numerical stability
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Old   February 25, 2018, 21:32
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Thanks.

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Old   July 20, 2018, 11:12
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Quote:
Originally Posted by Elham View Post
Dear Niam,

Regarding to phaseChangeHeatFoam the energy equation (25) in your paper is :

ddT + div (UT) - lapplacian (k/rhoC, T) = -1/rhoC *mdotTriplePrime*Hlg

there is a term in TEqn.H in line 19

Code:
- fvm::Sp(fvc::div(phi),T)
which is not corresponding to any term in energy equation.


The whole left side of TEqn is as following:
Code:
    fvScalarMatrix TEqn
    (
          fvm::ddt(T)
        + fvm::div(phi, T)
        - fvm::Sp(fvc::div(phi),T)
        - Foam::fvm::laplacian( k/rhoC_ , T,"laplacian(alphaEff,T)")
    /*    + (
            fvc::div(fvc::absolute(phi, U), p)
          + fvc::ddt(rho, KE) + fvc::div(rhoPhi, KE)
          )/rhoC
    */
    );
Would you please explain a bout it?

Regards,

Elham

Dear Elham,
It is also written in the documentation
https://openfoam.org/release/2-2-0/n...s-boundedness/


According to this link the same can be achieved with
setting divergence scheme as bounded in fvScheme file, e.g.
Code:
 div(phi,T)      bounded Gauss upwind;
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Old   May 18, 2022, 09:14
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Hi nimasam,
Could you tell me how you solved your problem if not possible to send .If you can send you can mail me to this mail : saicharan662000@gmail.com
Thanks and regards
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boiling, evaporation, interfoam, phase change

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