Hi I am a beginner in fluent. i would like to model a free surface flow of water passing a backward facing step. my problem is with defining the boundary conditions in the suface of water. I have used the symmetry boundary condition there which will result in a zero velocity for the vertical direction and putting the normal gradients of all other variables equal to zero.

Does anybody have any other idea. How can i use VOF here?

Thanks

Hi; For a free surface problem you need specify inlet and outlet and walls boundary conditions; like the water wave propagation capturing arround a ship. You do not need set a B.C. on the free surface. The flow conditions on the free surface are obtained during the calculation. Note that you are using a numerical method, not an analitical method.

Hope this help you

ROOZBEH