[borahdj2010]

Hi everyone! I am doing a multiphase flow simulation. I have a rectangular domain with a velocity inlet and opposite to the inlet a pressure outlet. The fluid flowing is water. On one of the side walls hydrogen bubbles are generated. As of now I use a constant velocity inlet there. But ideally I would like to model it as a source term or user defined function. The following conditions need to be fulfilled:
1) There is a distribution of bubble sizes
2) When the bubble layer is formed on the surface no longer hydrogen can be formed until the exiting bubble is carried away by the water flow.
3) Condition is that it is basically electrolysis. So only when the surface is wet hydrogen can be formed. I am ignoring the detailed reaction here and in stead just trying to get the bubble formation model simulated.

Could anyone of you help please? I am a bit new to multiphase flows a UDFs. Thanks in advance.