Greetings,
As understand from the below link, Bently SWMM engine calculates the Inlet capture efficiency first and then flow captured will be calculated.
https://communities.bentley.com/products/hydraulics___hydrology/f/haestad-hydraulics-and-hydrology-forum/200180/on-grade-inlet-with-swmm/597699#597699
We are working on storm Inlet modelling, need to understand the Inlet capture efficiency.
Could any one please explain to understand more on this?
regards
Ganesh Bala S
Hello Ganesh,
This link has information related to this: EPA SWMM solver versions used by SewerGEMS and CivilStorm.
If you are using the Bentley-enhanced version of the SWMM engine, this will include inlet calculations based on the HEC-22. While you may find information related to this in the SewerGEMS/CivilStorm Help documentation, you can find more specifics in the HEC-22 manual.
If you are using the EPA version of the SWMM engine, on grade inlets are assumed to be full capture.
Regards,
Scott
Hi Scott,
Thank you
we are using Bently-enhanced SWMM version, want to understand the equations how the Inlet hydraulics are calculated.
We started checking HEC-22 manual, can you share some additional details from your end to understand more effectively.
Regards
Design Engineer
Khatib&Alami Engineering Consultants Pvt. Ltd.
Page 4-43 (and likely other pages around there) of the HEC-22 manual appears to have the relevant info for on grade inlets.
For an inlet in sag when using the Explicit solver, the capture efficiency is reported as N/A. This is because the flow captured is determined based on the depth of the flow stored, and not the inflow to the inlet. If you highlight the Capture Efficiency field in the Properties display, you can see this in the explanation of the field at the bottom of the Properties display.
Thank You,
Agreed with you, also have worked out the equations in HEC-22 but couldn't match with our hydraulic model results exactly.
We has to show the calculations to match with hydraulic model results. Could you please share any worked out examples in brief for both On Grade & Sag conditions other than the examples from HEC-22.
Inlet details as shown in above image
Scott Kampa said:This is because the flow captured is determined based on the depth of the flow stored, and not the inflow to the inlet
Hello Scott
1-Why Inlet in Sag is not calculated based on "inflow" ?
2- If the capture efficiency is always 100%, that should be reported.
Mohamad
Do you have an example you can provide, of both the model and hand calculations? This link has information on sending the files.
Hello Mohamad,
But of these are related to the solver in question. You can get reported data on both of these by switching the solver to one that supports this particular workflow.