CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   Curvature of the interface using interFoam (http://www.cfd-online.com/Forums/openfoam/85562-curvature-interface-using-interfoam.html)

 Andrea_85 March 1, 2011 14:16

Curvature of the interface using interFoam

2 Attachment(s)
Hi all,

I am using interFoam to simulate multiphase flow in different geometries and I tried to write a little piece of code (writeCurvature.C that i call as a post processing) to calculate the curvature of the interface following the same method that openFoam normally use in the VOF method. (the calculations that i have done are identical to those in interfaceProperties.C). The problem is that I get strange result. I expected to find high values near the interface and values close to zero in the bulk but it is not!

i attached 2 jpg. one is the colour plot of alpha1 and the other one is the colour plot of the curvature that i got.
Any suggestion?

thanks
andrea

 Andrea_85 March 2, 2011 05:19

someone who has any idea why I find this curvature?
These are the calculations I've done:

Code:

``` reading alpha1 first then // now calc the gradients         volVectorField gradAlpha1 = fvc::grad(alpha1);         Info<< "Writing gradAlpha1 to " << gradAlpha1.name() << " in "             << runTime.timeName() << endl;         gradAlpha1.write();         // Interpolated face-gradient of alpha         surfaceVectorField gradAlphaf = fvc::interpolate(gradAlpha1);         dimensionedScalar deltaN_ =  1e-8/pow(average(alpha1.mesh().V()), 1.0/3.0);         // Face unit interface normal         surfaceVectorField nHatfv = gradAlphaf/(mag(gradAlphaf) + deltaN_);         // Face unit interface normal flux         const surfaceVectorField& Sf = mesh.Sf();         surfaceScalarField nHatf_ = nHatfv & Sf;         volScalarField curvature         (         IOobject         (           "Curvature",           runTime.timeName(),           mesh,           IOobject::NO_READ,           IOobject::AUTO_WRITE           ),         -fvc::div(nHatf_)         );```
The thing that I can not understand is if I'm doing something wrong or if it is normal to find such values

thanks
andrea

 All times are GMT -4. The time now is 08:39.