Hi All,
I am using SewerGem to model some surface water networks system consists of open channel and conduit. However i am having the following problem.
1. The peak runoff from catchment is smaller than the pipe capacity, but on profile, it shows it is surcharged and flood the upstream manhole/node.
2. The HGL on a number of profile show that the flow was not transferred to downstram conduit (see attached profile.
Having tried a difference scenarios, ie. headloss, type of conduit. the problem remains.
Could anyone help please?
Regards,
Boon
Hello Boon,
Are you running implicit solver or rational/convex solver?
Please look at the conduit properties for the conduit for which its showing as surcharged in the profile. If its surcharges then it will be shown in the conduit properties.
The mentioned profile is not attached herewith, could you please upload it again?
Also, we would need your model files to help you with it, please mention the particular elements and scenario to be looked at.
Sharing hydraulic model files
Sushma Choure
Bentley Technical Suppport
Boon,
1) If you are using the GVF-Convex (SewerCAD) solver, you may be referring to the issue explained in this wiki article:
Why does the profile for the system appear to be at odds with the results for the capacity?
2) If you are referring to the HGL "dropping" to the rim elevation due to flooding conditions, please see this wiki article (an illustration is included for comparison):
Why is the HGL reset to rim elevation for flooded structures?
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Thanks Jesse,
I am using sewergem with the dynamicwave solver.
the problem i have is that the simulation show high HGL at the initial/start of the computation and remain high (not reduced) at the end of the simulation. See attached plots.
however the flow graph in the pipe show normal flow.
could you help please.
Could you please send a copy of the models? Instructions for doing this can be found here: Sharing Hydraulic Models on the Haestad Forum.
Scott
Yes, having the model file will help us troubleshoot.
Based on the screenshots of the profiles, it appears to be showing the zero flow condition at the beginning and end of the simulation. Do you perhaps have the structure loss method set to "absolute" with a fixed headloss value entered, for manholes/catchbasins?