[Venky_94]

Hey Foamers!

I adapted the simple coupled level set solver (sclsVofFoam) developed by Sankar Menon (http://www.tfd.chalmers.se/~hani/kur...ankarMenon.pdf) based on Albadawi's work (10.1016/j.ijmultiphaseflow.2013.01.005) from OpenFoam 2.3 version to OpenFoam 9. My code is available in https://github.com/Venky-94/sclsVofFoam-OpenFoam9.

For my current research, I'm looking at bubble growth dynamics in highly viscous Newtonian fluids and certain non-Newtonian fluids, and I'm trying to implement an exponential averaging function for the property estimation in place of the linear interpolation available in interFoam currently.

The changes in the code are in solveLSFunction.H, and are as below, along with the default equation commented out.

//rho == rho2 + (rho1 - rho2)*limitedH;
rho == (rho2 + (rho1 - rho2)*pow(limitedH, 1.5*(nuMod1/nuMod2) + 0.75));

volScalarField& nuTemp = const_cast<volScalarField&>(mixture.nu()());
//nuTemp == (rho2*nuMod2 + (rho1*nuMod1 - //rho2*nuMod2)*limitedH)/(rho2 + (rho1 - rho2)*limitedH);
nuTemp == (rho2*nuMod2 + (rho1*nuMod1 - rho2*nuMod2)*pow(limitedH, 1.5*(nuMod1/nuMod2) + 0.75))/(rho2 + (rho1 - rho2)*pow(limitedH, 1.5*(nuMod1/nuMod2) + 0.75));

The issue I'm facing is that once I make the changes to the property estimation equation, I'm noticing an odd issue that the interface doesn't develop beyond a certain point (time step). Please check the clip (https://github.com/Venky-94/sclsVofF...estimation.avi)

I believe the issue has to do with this set of code for reinitializing the LS function in solveLSFunction.H. The value of corr in this case is (epsilon=1.5deltaX)/(deltaTau=0.1deltaX) = 15. If I reduce the corr value to 5, I see the interface developing until a further point and then stopping at that point. (refer to the picture https://github.com/Venky-94/sclsVofF...g/Corr%3D5.JPG)

// solve Level-Set function as the re-initialization equation
   Info<< "solve the reinitialization equation"     
       << nl << endl;

   psi == psi0;

   for (int corr=0; corr<int(epsilon.value()/deltaTau.value()); corr++)
   {
      psi = psi + psi0/mag(psi0)*(double(1)-mag(fvc::grad(psi)*dimChange))*deltaTau;
      psi.correctBoundaryConditions();
   }

The sample test case I used for this is available at https://github.com/Venky-94/sclsVofF.../Sample%20Case. The Reynolds number in this case is around 6, and if I just change the inlet velocity to raise the Reynolds number to 80, I can see the bubble developing and detaching from the needle without any issues. Can someone shed some light on this phenomenon for me? I can't seem to understand the underlying cause.