Outlet Control with Flap/floodgate 2

[timwoodpe]

I am trying to find a good reference on how to deal with a culvert with Outlet control (at 100 year flood stage) that includes a flood gate (flap valve). I have the standard equations and could add in the head loss from the gate (manufacturer information relating with a Q - hl relationship) into that equation as an additional head subtracted from the inlet head but I can't find a reference which I can point to showing that is legitimate.

Thanks, Tim

 

[dicksewerrat]

Just add it in as another head loss. Treat it as a fitting.

 

[gbam]

Hey Timwoodpe can you post from where you obtained that headloss information. I have looked unsuccessfully for many hours for that information. If you have the manufacturer name website or ect... it would be great!

I am not sure how to approach the situation especially if the outlet is submerged. There are forces acting against the pipe flow inaddition to the gate. I have tried to look at the head required to move the gate but not sure if it is correct. Please post what you find.

 

[cvg]

I think dicksewerrat is correct. with outlet control, you should have full pipe flow. so adding the headloss directly should be appropriate.

 

[gbam]

Would it depend on the test setup when the manufacturer or testing facility conducted the experimentation to determine the rating curve? The way I see it there would be two conditions. First, the additional head required to open the gate without tailwater and then the multiple configurations with tailwater acting against the flap gate. So if there is only a single rating curve one needs to be sure that the coditions are similar.

 

[bltseattle]

The Corps of Engineers Hydraulic Design Criteria is a great reference and includes flap gate hydraulics.

The general link is

http://chl.wes.army.mil/library/publications/hydraulic_design_criteria

And the specific part on Gates and Valves is:

http://chl.wes.army.mil/library/publications/hydraulic_design_criteria/300.pdf

Check out section #340 for flap gates.