IC and BC for slug flow
 

Dear all,

To simulate the flow of a slug through a mini channel, I have adpoted the VOF model with a constant surface tension. I have also assumed the flow to be laminar

For BC: I have specified a velocity inlet, a outflow and non-slip wall condition.

For IC: I have patch a gas bubbles cylindrical in shape in the channel (volume fraction 1)

Square channel of size 2 x 2 X 50 mm grid size of 26 X 26 X 635

I will get an error message of "Too many sub time step. The velocity field is probably diverging....... Reduce time step" when im interating.

May i know what is the problem? I have tried to reduce the under-relaxation factors but was unable to get satisfactory results.

Any suggestions will be appreciated

Thanks in advance.