Moving interface
 

Hi,

How can I define moving interface (or moving mesh)for two immicible fluid (for example air andwater) in a vertical tube. I tried VOF method but not converged. I don't want to mass diffusion interaction of phases.

Thanks...

Re: Moving interface
 

Just for using VoF , you do not need the Moving mesh even though the interface is moving! Switch off moving mesh. Use unsteady solver.. Use piso fopr pressure.. Start with a time step say 1 e-3 and inner iteration 50..

Best, Ady

Re: Moving interface
 

Dear Andy,

Thanks, for your attention. I defined VOF model my problem, but the interface is interpreted other phase and then uncertain. I dont want phase interaction or mass diffusion. Are there any information this topic.

Best regarding, UNAL

Re: Moving interface
 

Hi,

U can define motion to interface if u know how it is going to deform. Best way to solve this problem is to use VoF only. I had tried with oil and waiter and it works fine. If the solution depends only on density difference, then try VoF.

Re: Moving interface
 

Hi Mahesh Thanks...I try to solve this problem is to use VOF only. But I have a convergence problem. I choose time step is 1e-3 and pressure PISO. My fluid is water and air. Are there any other options to define problem.

best regard