I am doing a free surface analysis. It is a manifold supplying coolant to the punch die assembly. Coolant is not fully filled in the manifold all the time (free surface). There are five outlets. I am not understanding what BC I should use for the outlets. Pressure or split outlet or any other. I do not know the flow split. So when I give atm pressure it diverges after 2 timesteps. If I use flow split outlet based on their area, run does not start at all, it comes out before starting. (some OS error)

Kindly help. Thanks in advance.

Have you tried to use piezometric pressure with environmental option on?

Hope this helps....

Thanks 4xF. It is running with same pressure BCs now after reduction of pressure under relaxation factor.