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Inlet Question
2

Inlet Question

Inlet Question

(OP)
I have a scenario where I need to verify that a proposed inlet will operate at 100% efficiency. The inlet layout consists of 4 inlets spanned over 587ft with the greatest distance between two inlets being 184ft.

I would think that the steps I need to take in assuring the need efficiency would be as follows:
Steps
1:Define Runoff (TR-55)
   Look at area above (which is .00018mi^2) and determine the runoff using qP=Qu*Am*Q.
2:The area is impervious and is curbed (Type F) so calculate the discharge of the gutter. (Which Im not sure on the exact way how)
3: Look at the Inlet type being used (Curb-Opening) and determine the capacity of it. The reference I have differs from DOT specs.
4:Given all the above variables I can determine the efficiency of the inlet (E= Discharge intercepted by inlet/total discharge approaching inlet)

I think this is the steos needed to verify an inlets efficiency. I could be wrong though.

Thanks any advice is very much appreciated!!!

RE: Inlet Question

First, 100 % efficiency is NOT POSSIBLE !
Second, a drainage area of 0.00018 square miles is only 0.115 acres which is only about 5000 square feet which is probably too small to warrant the use of the TR-55 method.
Third, you have not defined any of the terms in the equation  " qP=Qu*Am*Q".
Fourth, where does this equation come from and why do you think it is valid AND is applicable ?
Fifth, someone on this forum may know what a Type F curb is but most if us probably don't have any idea what you are talking about.
Sixth, the discharge capacity of a gutter may be calculated using the Manning Equation or a free program like Visual Urban ( Google it ).
Seventh,don't know what a "steos" is.

Try again.

RE: Inlet Question

An inlet grate located in a sump condition, (0.6' below the gutter grade for straight line flow), is 300% to 500% greater than a straight grade flow condition inlet grate.  As stated in RWF7437 posting,  Mannings equation gives Q for gutter full flow.  Check with grate manufacturer for flow characteristics under both flow conditions.

RE: Inlet Question

(OP)
Reply to RWF7437

1. Efficiency is equal to discharge intercepted by inlet by the total discharge approaching the inlet, correct? If so by theory the outlet could operate over 100%
2. If not the TR-55 what method should I use?
3. qp=Qu*Am*Q was taken from the TR-55 where:
   Qu= unit peak discharge=1000 csm/in
   Am= drainage area=0000183mi^2
   Q= Runoff=7.06in
4. These values were determined using the TR-55 method
5. Type F curb is a type of curb defined by FDOT "Flordia Dept. Of Trans."
6. Thanks for the tip on how to calculate discharge capaciy of a gutter. I used a method that was in a reference manual I have "Stormwater Conveyance Modeling and Design, by Haestad"
7. "steos" was a type-o I meant to say "steps"

I am a recent grad that is trying to become a great engineer, so please all bear with me and I appreciate your time and help.

Thanks!!

RE: Inlet Question

(OP)
Reply to TerryScan

Thanks I will look into that!! At first I considered using the rational method but another EI suggested that maybe I look into TR-55. I guess I should have stayed with my first thought..

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