Grate Inlet modeling w/ HydroCAD?
Grate Inlet modeling w/ HydroCAD?
(OP)
Has anyone used HydroCAD to model grate inlets or Catch Basins in order to verify that their capacities are adequate for a given storm event?
HydroCAD tech support keeps sending me back to the general support on their website.
I want to keep the model simple. I'm not sure how to deal with the tailwater issue nor any overflow. Does overflow mean that the grate inlet is undersized and will back up (pond) with storm water?
HydroCAD tech support keeps sending me back to the general support on their website.
I want to keep the model simple. I'm not sure how to deal with the tailwater issue nor any overflow. Does overflow mean that the grate inlet is undersized and will back up (pond) with storm water?





RE: Grate Inlet modeling w/ HydroCAD?
HydroCAD should be able to check inlet conditions to make sure that the catch basin headwater depth doesn't get too high, although we used a simple nomograph for headwater depth, which is fairly easy if you don't have too many inlets.
If you have overflow I would suspect that your pipe is too small. Bypass flow is usually a spread problem due to a gentle road slope maintaining sheet flow.
RE: Grate Inlet modeling w/ HydroCAD?
Also, do you have a website link that I can go to for nomographs for headwater and info. on tailwater/headwater?
RE: Grate Inlet modeling w/ HydroCAD?
I haven't modeled storm drains in HydroCAD except for one or two exercises in a college class. I did find this, though:
That "More info" link seems pretty useful.
RE: Grate Inlet modeling w/ HydroCAD?
Although you CAN do grate/orifice modeling in HydroCAD, this is generally as an outlet control device on a detention pond or storage area. In most cases, the HydroCAD model will include the catch basin with a culvert outlet, but the inlet grate is omitted from the model.
Remember that HydroCAD deals only with "outlet" controls. If you do want to model the "inlet" grate this must be done as an outlet control on an above-grade "pond". Although this is possible, is can get unnecessarily complex, and is rarely done. For complete details please see "What about the grate?" at www.hydrocad.net/sewers.htm This is the exact question you've asked...
RE: Grate Inlet modeling w/ HydroCAD?
RE: Grate Inlet modeling w/ HydroCAD?
RE: Grate Inlet modeling w/ HydroCAD?
RE: Grate Inlet modeling w/ HydroCAD?
You can go to their webpage and download UD-Inlet.
http://www.udfcd.org/downloads/down_technical.htm
Maybe this link will work also.
http://ww
Colin McKernan
RE: Grate Inlet modeling w/ HydroCAD?