While doing some testing with SUDA on a previous project that was done in GEOPAK Drainage, I noticed that I was getting some abnormal large spreads for curb inlets in a sag. After I imported the .gdf file into a new file for SUDA testing, the spread was 10.12' while the spread in GEOPAK Drainage was 3.1138'. They should be somewhat close. Why is this??
One thing I did change in SUDA was in the inlet catalog, I changed the default curb opening length from 5 to 60 (60"=5'). Then I ran the computation again and it was somewhat close on the spread.
Maybe the program is figuring the curb opening length incorrectly?? Please look into this. Thanks.
Hello Chad,
Thank you for sharing your model DGN file. I was able to open it in Power GeoPak V8i (08.11.09.878). To test I ran the scenario "NW Base Analysis 2 year storm" wherein I got the spread for inlet DI 71 as 10.12 ft.
Since GeoPak uses storm-sewer models up to SS4 only, I had to convert your .stsw file linked to the DGN to the latest version of CivilStorm (10.01.00.72).
I then attached this .stsw to a blank DGN in Open Roads Designer. I analyzed the same scenario in SUDA but the spread value was same (10.12 ft). I am using Open Roads Designer (10.03.00.43).
So it seems that the HEC-22 equations are working similarly for both GeoPak and Open Roads Designer.
However I require the .gdf file for this project to open in GeoPak Drainage which you have not shared. To understand the difference in spread calculations please share the .gdf file.
Also please share the workflow you are adopting to open the file.
Additionally also share details about the scenario you tested, and the .stsw model.
Regards,
Yashodhan Joshi
The .gdf file should be out there now for you to look at. Basically I am just opening a file in PowerGEOPAK (08.11.09.893) and then opening GEOPAK Drainage to open up the .gdf for review. Nothing special with that.
Let me know if you have any other questions.
We're having some trouble opening the GDF file, but I'm not sure if we need it. See my previous post - it is very likely that the Haestad solver (used in SUDA/OpenRoads) has a different interpretation of HEC-22 in this specific case, yielding different results.
First, there appears to be a difference in input in the screenshot of the GEOPAK file, the SUDA model, and the model you sent. Here are some observations:
- In the GEOPAK screenshot, the Flow is 1.81 (CFS?) but in the SUDA screenshot and the model, the flow is 1.99 CFS
- In the GEOPAK screenshot, there appears to be a local depression of 3 inches with a depression width of 3 ft, in the SUDA screenshot it is 4 inches and 2 ft, and in the model file, there is no local depression.
- The "computed head" in the GEOPAK screenshot appears to be from HEC-22 equation 4-28 (I matched the result with a hand calculation)
- The depth (and thus spread) in the Haestad solver (and in SUDA) is a bit more complex, as explained in the forum discussion previously linked to.
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Let me do some checking again with our test files, But I still think something isn't correct in SUDA. If I have my sag inlet set to a curb opening inlet (Curb - Type T 5), it has a spread of 10.12.
But if I change the sag inlet to a grate inlet (Grate CV - Type A-D CV 4x2), I get a spread of 8.06.
I would seriously think the curb opening inlet would have a considerably smaller spread than the grate inlet.
Along with that thought, when I set the local depression for the curb inlet in the inlet catalog to 0, I am getting a gutter depth of .378 and spread of 13.
Now if I change the local depression for the curb inlet to 2,4,6, or whatever number, I am getting a gutter depth of .320 and spread of 10.2.
So.......
#1 - Why isn't the gutter depth changing on the different local depression depth I gave the program, if it is measuring from the low point on the depression for the inlet?
#2 - Shouldn't the "0" local depression inlet have the smaller gutter depth than the inlet that has a local depression value?
Sorry the headaches and confusion with this matter. Just want to make sure everything is correct before setting up our standards correctly.
Thanks and let me know.
Hello Chad, the inlet calculations tend to be quite complex, as you can see from some of the links I mentioned earlier.
I am going to work with our developers to get a more concrete answer regarding exactly how the depth and spread are computed in your particular case. Thanks for your patience.
Hello Chad, just a quick update on this. I have some information from our developers on how the calculations are done in your example cases and am working on deciphering them so the process can be explained. I expect to have an answer for you today. Thanks again for your patience.