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August 23, 2007, 15:47 
Hello,
I am interested in i

#1 
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Vinay Ramohalli Gopala
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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, 

August 24, 2007, 05:58 
Hi Vinay
Check out this li

#2 
Senior Member
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Hi Vinay
Check out this link in the forum http://www.cfdonline.com/OpenFOAM_D...ges/1/172.html Regards Jaswinder 

February 26, 2009, 08:34 
The links seems to be dead.
C

#3 
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Fabian Roesler
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The links seems to be dead.
Can anybody post the correct link of the discussion? Thanks allot in advance. Regards Fabian 

February 17, 2010, 11:32 
interface area

#4 
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Roman Thiele
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Did you ever find a solution to the problem of calculating the interface area within the cell?
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~roman 

July 31, 2010, 08:25 
never found one

#6 
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Roman Thiele
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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.
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~roman 

July 31, 2010, 10:50 
mathematical method

#8 
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Roman Thiele
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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(1alpha1); 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(limitedAlpha10.5)*maxArea*2.0*limitedAlpha1) + (pos(limitedAlpha10.5)*maxArea*(2.0*( limitedAlpha1  1.0))) ); }
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~roman Last edited by romant; July 31, 2010 at 16:36. Reason: missing factor in calculation for the area 

August 1, 2010, 05:29 
create an accessible volume field

#10 
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Roman Thiele
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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();
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~roman 

October 30, 2014, 04:43 
Length of the interface

#11 
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Vignesh
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Dear All,
I know this thread is old but, I would like to know how to calculate the length of the interface in interfoam ?
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Thanks and Regards Vignesh TG 

October 30, 2014, 04:47 

#12 
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Roman Thiele
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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.
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~roman 

October 30, 2014, 11:08 

#13 
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Vignesh
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Thank you !! Now i get it
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Thanks and Regards Vignesh TG 

June 8, 2015, 08:13 

#14 
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rkhr
Join Date: May 2011
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HI Foamers,
I am trying to implement Roman's code but I have following error: PHP Code:


June 8, 2015, 10:18 

#15 
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Roman Thiele
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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.
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