I am trying to model discharge to a manhole without submerge, and found Discharge to Atmosphere element (type orifice) would be the best way.
But I am not sure how to setup the pressure drop and flow properly. I reviewed this webpage http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/3443.aspx, but still not sure. It seems I need to determine a typical flow and then use the equation to calculate the headloss. But my questions are:
1 what does typical flow mean, and how to determine it? In different scenarios e.g. different number of pumps in operation, will this typical flow change?
2 It seems the typical flow is not sensitive in intial condition calculation. But it does impact transient pressures. How does typical flow and headloss kick in the transient calculation?
Thanks for your time,
Hailiang