BcData in Dam simulation

Julien

Dear users of Flow-3D,

I am currently modelling a dam with pipes(with v 9.3), so that I have free surface as upstream which is not the case in the dam's structure.

Despite I use free surface option.

My mesh stops under the dam, so in the middle of the pipes (there are 3 pipes, 80 meters long)), and I have used different downstream boundarie conditions (Outflow, Specified pressure, continuative...). But the head trought my pipes increases of 2 meters in the last 30 meters of the mesh (in x direction)...physically impossible...

I suspect it is caused by the pressure in the flow, but... Does anybody know why? It seems to be strange. What kind of boundarie condition shall I use (I don't want to impose the flowrate)?

Thanks

Julien