Pond Outlet - Standpipe with rectangular notch

[Zuver]

How do you model a standpipe with a 1.6 inch wide notch in a 12 inch diameter pipe that 0.6 feet tall? The sharp crested weir module requires a minimum crest length of 0.5 feet that I cannot seem to change?

 

[psmart]

The sharp-crested weir calculations include end-contractions and adjustments for crest height that are not appropriate for very short crest lengths, hence the minimum length.

In your case, model the notch as an orifice instead of a weir. The orifice calculations allow for weir flow when the opening is partially submerged. Using an orifice will also prevent double-counting any flow over the top of the riser.

For further details please click the Help button on each of the outlet screens.


Peter Smart
HydroCAD Software

http://www.hydrocad.net