Notched weir wall modeling question
Notched weir wall modeling question
(OP)
What is the correct way to model a notched weir wall? I have a 0.25’ by 1ft tall notch in my weir wall. The wall is 6 ft wide (inside diameter of the structure). I received a review comment from the governing unit in charge instructing that the weir width should be modeled as 5.75ft as .25 ft is already accounted for in the weir notch. The change does not affect the model at all but which is actually the correct way to model the wall?





RE: Notched weir wall modeling question
It is a 6-foot wide weir when that comes into play, not 5.75'
RE: Notched weir wall modeling question
One solution is to use the full 6' length of the wall, and set the Rise for the v-notch to 1 foot. This effectively makes the v-notch an orifice at high heads, with the additional flow area handled only by the 6' weir.
Another option is to use a custom weir/orifice, which basically allows you to draw the entire structure (notch plus wall) using a single outlet device.
For further details and illustrations please see www.hydrocad.net/weir2.htm
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Notched weir wall modeling question
RE: Notched weir wall modeling question
I suggest that you use 6 feet AND set the rise on the v-notch to 1 foot. This will eliminate any overlap in the flow area.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Notched weir wall modeling question
A custom weir, as shown in your screen shot, is also a good way to go.
Peter Smart
HydroCAD Software
www.hydrocad.net