Hi all!

I am simulating the free surface by using VOF model for 3D, however I face a problem is:

From Initial, running with Steady, the solution gives a error.

Meanwhile, running with Unsteady is smooth solution.

When I switch from Unsteady into Steady, the Continuity Residual is very high (More than 0).

Everyone can suggest for me the reason and how to solve this, because I need Steady solution to check result quickly.

Thank you all!

It is recommended to run VOF model only in unsteady state since it involves tracking of the interface with every timestep. Steady state VOF solution has very little significance. To obtain a steady state solution, you can run an unsteady problem till you reach steady state.