CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Calculating Interface Area with InterFoam

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree1Likes
  • 1 Post By romant

Reply
 
LinkBack Thread Tools Display Modes
Old   August 23, 2007, 15:47
Default Hello, I am interested in i
  #1
New Member
 
Vinay Ramohalli Gopala
Join Date: Mar 2009
Location: Netherlands
Posts: 13
Rep Power: 8
gopala is on a distinguished road
Hello,

I am interested in implementing Mass and Heat transfer across the interface using VOF (interFoam solver), which requires an accurate description of the interfacial area in each cell. Can someone suggest a way to calculate the interfacial area using the present interFoam VOF implementation?

Thanks in advance,
gopala is offline   Reply With Quote

Old   August 24, 2007, 05:58
Default Hi Vinay Check out this li
  #2
Senior Member
 
Join Date: Mar 2009
Posts: 248
Rep Power: 9
jaswi is on a distinguished road
Hi Vinay

Check out this link in the forum

http://www.cfd-online.com/OpenFOAM_D...ges/1/172.html

Regards
Jaswinder
jaswi is offline   Reply With Quote

Old   February 26, 2009, 08:34
Default The links seems to be dead. C
  #3
Senior Member
 
fabian_roesler's Avatar
 
Fabian Roesler
Join Date: Mar 2009
Location: Bad Friedrichshall, Germany
Posts: 161
Rep Power: 8
fabian_roesler is on a distinguished road
The links seems to be dead.
Can anybody post the correct link of the discussion?
Thanks allot in advance.

Regards

Fabian
fabian_roesler is offline   Reply With Quote

Old   February 17, 2010, 11:32
Default interface area
  #4
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
Did you ever find a solution to the problem of calculating the interface area within the cell?
__________________
~roman
romant is offline   Reply With Quote

Old   July 31, 2010, 05:34
Default
  #5
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
hi friends
did you find any way to calculate interface area ?
nimasam is offline   Reply With Quote

Old   July 31, 2010, 08:25
Default never found one
  #6
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
Hej,

I tried finding a solution, but I in the end created a model to simulate and predict the size of the interface area. I assumed that the size of the cell is regular. Then calculated the area that is double diagonal within the a regular cell (in this case a cube then) and varied the size of the interface area with the amount of alpha1 within the cell, max at 0.5 alpha1 and full size of the double diagonal area.

Of course this can be made better. Additional information that can be used within such a model can be the velocity, the angle at which the interface is within the cell and the irregularity of the cell.
__________________
~roman
romant is offline   Reply With Quote

Old   July 31, 2010, 10:36
Default
  #7
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
hi roman
could you please describe ur method step by step or mathematically because i didnt get what you said it was ambiguous for me

thanks in advance
nimasam is offline   Reply With Quote

Old   July 31, 2010, 10:50
Default mathematical method
  #8
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
assume a regular cell. in the case of a hexahedral cell this means, a cube with sides of length a. This length is obtainable by using the volume of a cell,V , and taking the third root.

You can put a plane diagonally through the cube. The size of this plane is given by

Amax =√(3) * V^(2/3)

When the cell is now filled with phase 1, you can read the alpha1 value. The maximum area, Amax, is now varied based on the alpha1 value. with

A = Amax*2 * alpha1; 0 ≤ α < 0.5
A = Amax*2(1-alpha1); 0.5 ≤ α ≤ 1


The code that I used for this is

Code:
Foam::tmp<Foam::volScalarField>
Foam::phaseChangeTwoPhaseMixtures::AlbaNovaInterface::interfaceArea() const
{
    // return the interfacial area based on model for interfacial area
    // returns dimensions Area

    // model based on regular volume cells, taking the largest cut area
    // as maximum for area, linear increase and decrease with alpha
    const volScalarField& cellVolume =
        alpha1_.db().lookupObject<volScalarField>("cellVolu");
    volScalarField limitedAlpha1 = min(max(alpha1_, scalar(0)), scalar(1));

    const dimensionedScalar
            areaFactor("areaFactor",dimensionSet(0,2,0,0,0,0,0), 0.0);

    volScalarField interfaceArea = alpha1_ * areaFactor;
    volScalarField maxArea = alpha1_ * areaFactor;

    maxArea = sqrt(3.0)*pow(cellVolume,(2.0/3.0));
    return tmp<volScalarField>
    (
      (neg(limitedAlpha1-0.5)*maxArea*2.0*limitedAlpha1) +
        (pos(limitedAlpha1-0.5)*maxArea*(-2.0*( limitedAlpha1 - 1.0)))
    );

}
I know that the code is not the cleanest and strictest code. For example at the part where the field with the interface areas are created, but it was at a time I didn't know too much yet :-)
__________________
~roman

Last edited by romant; July 31, 2010 at 16:36. Reason: missing factor in calculation for the area
romant is offline   Reply With Quote

Old   August 1, 2010, 02:53
Default
  #9
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
thank roman but could please tell me how could u get "cellVolu" in ur code ?
nimasam is offline   Reply With Quote

Old   August 1, 2010, 05:29
Default create an accessible volume field
  #10
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
Hej,

I created a volume field in createFields.H

Code:
// create access for cell volumes during runtime
    // needed by AlbaNovaInterface

    volScalarField cellVolu
    (
    IOobject
       (
        "cellVolu",
        runTime.timeName(),
        mesh,
        IOobject::NO_READ,
        IOobject::NO_WRITE
       ),
        mesh,
    dimensionedScalar("zero", dimVolume, 0.0)
    );
    cellVolu.internalField() = mesh.V();
this is now available throughout the runtime. It is never written, but is readable.
__________________
~roman
romant is offline   Reply With Quote

Old   October 30, 2014, 04:43
Default Length of the interface
  #11
Member
 
Vignesh
Join Date: Oct 2012
Location: Darmstadt, Germany
Posts: 33
Rep Power: 4
vigneshTG is on a distinguished road
Dear All,

I know this thread is old but, I would like to know how to calculate the length of the interface in interfoam ?
__________________
Thanks and Regards

Vignesh TG
vigneshTG is offline   Reply With Quote

Old   October 30, 2014, 04:47
Default
  #12
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
One way if determining the interface size has been described in the previous posts. A length would not be a real size for a cells, as a cell 3D and you need an area.
vigneshTG likes this.
__________________
~roman
romant is offline   Reply With Quote

Old   October 30, 2014, 11:08
Default
  #13
Member
 
Vignesh
Join Date: Oct 2012
Location: Darmstadt, Germany
Posts: 33
Rep Power: 4
vigneshTG is on a distinguished road
Quote:
Originally Posted by romant View Post
One way if determining the interface size has been described in the previous posts. A length would not be a real size for a cells, as a cell 3D and you need an area.
Thank you !! Now i get it
__________________
Thanks and Regards

Vignesh TG
vigneshTG is offline   Reply With Quote

Old   June 8, 2015, 08:13
Default
  #14
Senior Member
 
rkhr
Join Date: May 2011
Posts: 211
Rep Power: 7
Kanarya is on a distinguished road
HI Foamers,

I am trying to implement Roman's code but I have following error:
PHP Code:
                                          ^
In file included from alphaEqnSubCycle.H:35:0,
                 
from myInterConPhaseChangeFoam.C:83:
alphaEqn.HIn function ‘int main(intchar**):
alphaEqn.H:86:3error‘mDotCondense’ was not declared in this scope
   mDotCondense 
mDotcAlphal*(1-alpha1); // multiply by (1-alpha1) because given back that way
   
^
In file included from alphaEqnSubCycle.H:40:0,
                 
from myInterConPhaseChangeFoam.C:83:
alphaEqn.H:86:3error‘mDotCondense’ was not declared in this scope
   mDotCondense 
mDotcAlphal*(1-alpha1); // multiply by (1-alpha1) because given back that way
   
^
In file included from myInterConPhaseChangeFoam.C:61:0:
/
usr/local/OpenFOAM/OpenFOAM-2.1.0/src/finiteVolume/lnInclude/readTimeControls.H:38:8warningunused variable ‘maxDeltaT’ [-Wunused-variable]
 
scalar maxDeltaT =
        ^
make: *** [Make/linux64GccDPOpt/myInterConPhaseChangeFoam.oError 1 
Can you help me?
Kanarya is offline   Reply With Quote

Old   June 8, 2015, 10:18
Default
  #15
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Stockholm, Sweden
Posts: 359
Rep Power: 12
romant is on a distinguished road
I think to understand how the code is implemented, you need to take a look at how the other models for cavitationFoam are implemented. Different models could be chosen in version 1.7 for which this model was created. I am not sure what it looks like today (as of version 2.3 or 2.4).

The models that I implemented were not hard coded into the solver but where as all the other models selectable.
__________________
~roman
romant is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to plot time vs distance traveled by the interface interFoam asaha OpenFOAM Paraview & paraFoam 9 January 26, 2011 09:05
InterFoam freeSurface area calculation with sampleSurface jaswi OpenFOAM Post-Processing 9 December 10, 2009 12:07
How to calculate liquid volume as the interface moves for interFoam Solver asaha OpenFOAM Running, Solving & CFD 25 October 21, 2009 04:34
Problems calculating field gh with interFoam cricke OpenFOAM Running, Solving & CFD 0 December 10, 2007 08:17
How to access interface area in vof model??? Asghari FLUENT 0 April 16, 2007 08:12


All times are GMT -4. The time now is 16:52.