Learning Forum

[Guojun]

Hello everyone,nI was simulating two-phase flow in a tube using VOF and Eulerian method. There is some information about the cases.ncase 1: VOF method, no surface tension force.ncase 2: Eulerian method, no interfacial force.ncase 3: Eulerian method, default interfacial force(schiller-naumann).nAnd I found that the results of case1 and case3 were similar. So I wonder is there any interfacial force or friction force between gas and liquid when using VOF method. I read the user's guide and theory guide, and I didn't find the answer. Could you please tell me? Thanks.nGuojunn

[Karthik Remella]

Hello,nNo, the Schiller-Naumann model uses the following equation to estimate fluid-fluid drag (default option). nThis method is not present in the VOF model.nPlease describe the problem you are attempting to solve in detail (with some screenshots) and we might be able to understand what might be happening here.nThank you.nKarthikn

[Guojun]

Hello Karthik,nThank you. I am simulating the counter-current gas-liquid flow in a tube using the 2D axisymmetric model. The gas velocity and liquid velocity are -1 and 1m/s, respectively. nnI thought that there is no fluid-fluid interfacial force when using the VOF method, so the results of case 1 and case 2 should be the same. However, case 2 cannot converge, and the results of case1 and case3 are similar. The pictures show the liquid fraction of case1 and case 3. So I wonder maybe there is a fluid-fluid interfacial force in the VOF method. Many thanks.nn