The interface in my VOF simulation involving liquid-vapor appears to be spread over three to four cells.
The simulation is converging as the residuals fell below default settings and the area of the interface has become constant with further iterations/timesteps.
The fluid properties of both liquid and vapor are the same. Vapor lying above liquid. Gravity is considered.
I am using PISO/LeastSquareCell/SecondOrder/GeoReconstruct/Warped-FaceGradientCorrection/HigherOrderTimeRelaxation; Explicit VOF formulation with implicitBodyForce; and A timeStep of 1e-06 s. Mesh is 3D unstructured - tetrahedrons
I want the interface( 0<VOF<1) to appear sharp, i.e., it should be within one or two cells atmost.
To achieve it, I tried the following:
1) Refining the mesh in Workbench and running new simulations. Though I achieve convergence, the interface is not sharp
2) Adapting the mesh in Fluent. As soon as I adapt the mesh using GradientAdaptation, I am not achieving convergence even with lower timesteps and the interface appears wavy.
I request help on how to get a sharp interface, i.e., the region 0<VOF<1 should lie within one or two cells.
Thanks & Regards,