Pond outlet w/parallel culverts

[GDriscoll]

I have a perforated riser outlet structure that outlets to two paralell culverts. The culverts are 30" and 12" RCP pipes at diffrent inverts, so a discharge multiplier won't work. How do I route the 8 rows of 0.5" orifaces to two different pipes?

Thanks,
Greg

 

[elminer]

Greg,

Try this. Model your detention/retention area as a pond with only the 0.5" orifice outlets. Then direct the flow into a second pond where you describe the elevations, volume and outlets of the riser itself. This should get around trying to figure out how to direct which orifice to what outlet.

This also works well if you have surface ponding and are trying to model flow through a catch basin/inlet grate.

Ed

 

[GDriscoll]

That's an interesting workaround, but I'm still trying to wrap my head around it. Once I get my orifice flow into the next pond, how do I model the culverts? As primary and secondary devices, or as two devices into a primary outlet?

Also, would you happen to have an example file that you could email me? gdriscolljr@netscape.net

Thanks,
Greg

 

[psmart]

If both culvert outlets are routed to the same place, they are generally both set to primary. As a general rule, the secondary discharge is used only when you want to route the flow separately. (A flow diversion)