Hello all

I use finite volume method and VOF method to simulate the filling process of a viscous liquid in a mold. As a two-phase flow. I meet some problems in boundary conditions. I apply no-slip boundary conditions at the mold wall filled with liquid, i.e. u=0. I want to apply free-slip boundary conditions at the mold wall filled with gas, but I don't know how I describe the free-slip boundary conditions by means of the formulation. Who can give me some advice? Thanks in advance.

Regards

Yang

nice idea...

Hi, For providing free slip BC,I think you should keep two things in mind 1. all the normal velocities normal to free slip wall should be zero. 2. gradient of velocity parallel to wall should be zero. that is v(wall)=v(wall-1). As the wall shear stress is zero for free slip case. Bye Ram Dayal

Thank you very much for your reply!

By the way, what about the normal viscous stress at the wall? Thanks in advance!

Hi, Generally the wall BC's are specified via velocity components on the wall. And the wall stresses are the part of solution. Thats what I think. Bye Ram Dayal

Thanks!

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[swiych]

i am puzzled by this free-slip and no-slip condition, is it apply to closed boundaries? i hope someone can elaborate on this to help me out. Thanks.