Slotted Gate/Narrow Channel?
Slotted Gate/Narrow Channel?
(OP)
I'm trying to develop a rating curve for an existing control structure that has a slotted gate like opening and I'm looking for advice on what flow equation to use.
Here is what the control structure entails; it is 17-feet across the front as the stream flows through the trash rack. The trash rack consists of ten 5-inch diameter pipes. Immediately on the downstream side of the trash rack there is a 1-foot thick wall perpendicular to the stream with a 3-foot wide opening and it extends approx. 17-feet high. From here it discharges into a 17-foot wide by 10-foot long (in the downstream direction) and 20-feet high. Then it enters a 7-foot wide by 6-foot high concrete box culvert.
If I lost anyone, here is another way to picture the control structure is it is a box (17-feet wide by 10-feet long by 20-feet high) with 3-foot door extending 17-feet towards the top.
Anyways does anyone have advice on what equation should be used for the 3-foot opening? I was thinking of using Manning's equation. Is there any other equations I should consider?
If you have any other questions or need additional info let me know.
Thanks,
Rob
Here is what the control structure entails; it is 17-feet across the front as the stream flows through the trash rack. The trash rack consists of ten 5-inch diameter pipes. Immediately on the downstream side of the trash rack there is a 1-foot thick wall perpendicular to the stream with a 3-foot wide opening and it extends approx. 17-feet high. From here it discharges into a 17-foot wide by 10-foot long (in the downstream direction) and 20-feet high. Then it enters a 7-foot wide by 6-foot high concrete box culvert.
If I lost anyone, here is another way to picture the control structure is it is a box (17-feet wide by 10-feet long by 20-feet high) with 3-foot door extending 17-feet towards the top.
Anyways does anyone have advice on what equation should be used for the 3-foot opening? I was thinking of using Manning's equation. Is there any other equations I should consider?
If you have any other questions or need additional info let me know.
Thanks,
Rob





RE: Slotted Gate/Narrow Channel?
Also, since this appears to act as a trash rack, isn't it possible it may be frequently clogged and that any calibration or rating curve for it would not be valid under those conditions ?
One wonders why you want to get a rating curve for it ?
Good luck
RE: Slotted Gate/Narrow Channel?
Good luck
RE: Slotted Gate/Narrow Channel?
Thanks for your reply. There was a rating curve developed for this control structure in the 80's, but the city doesn't think it is valid. I believe the city is hoping that there has been some research with something similar and we can take that equation and apply it to this structure.
I do have and know RAS. I think maybe this weekend I'll drop this configuration into RAS and see what it gives me.
However I'm still up for ideas and/or possible equations or papers related to something similar.
Rob
RE: Slotted Gate/Narrow Channel?
The HEC-RAS approach is probably the easiest for your case and should be convincing to anyone who knows anything about open channel hydraulics.
Good luck with "the City"
RE: Slotted Gate/Narrow Channel?