Flow with high surface tension
 

I am looking for advices on the problems that I am having with the following simulation;

The geometry is 2d. There is a vertical channel entrance and this connects to a horizontal channel. The liquid flow is coming from the top portion of the vertical channel and flowing downwards. Some portions of the horizontal channel are openings for air flow. The aim of the simulation is to observe free surface in the vertical channel section where the bottom wall can also be moved.

I have obtained some interesting results with water and air. Now I switch to very high surface tension (10 times water) and I am observing very poor convergence and I see that while the liquid moves downwards, there is no a clear interface.

For the convergence, i follow the hints given in help files but did not really improve the convergence much.

Please let me know your suggestions and expierences on such flows.