The model does not complete the run when I do 24 hours simulation, however, it is run when run less simulation time, for example, it is run for 12 hours in spite of using the same parameters in the calculation option.
I upload the model to the secured link for your reference and below are the screenshots of the notification and the calculation summary but could not figure out what is the problem, also before run the validation pass without any problems.
Regards,
Mohamad Azzam
Hello Mohammad,
This is a known issue which is documented in this wiki: "Access violation in module execRouting" when computing with SWMM solver
If you have inlets in your model, check if they are "on-grade" but don't have any downstream gutters or try changing the inlets to "in-sag".
Yashodhan Joshi
Hello Yashodhan,
It is the same physical network, that is running when using other time simulation and can complete the run there, the problem is only when select 24 hours run simulation, if the problem is regarding the inlet and gutters so the run should not be completed for any other simulation. So why we are able to do the complete run with simulations less than 24 hours but the run does not complete in when select 24 hours?
Mohamad
Its taking a long time to compute this model. However, I noticed that the .stsw.sqlite database was very large (order of 2.6 GB0 and noticed a lot of Change Tracking records. I deleted these using the steps provided here and brought down the database size around 30 MB.
I am running it with a very large time step for now (6 hours) but it still is taking a lot of time. Meanwhile you can also look at some options provided in this article since this error can also be related to large instabilities in the model.
Yashodhan Joshi said:I deleted these using the steps provided here and brought down the database size around 30 MB
I was not able to access the steps to reduce the size of the database.
Yashodhan Joshi said:I am running it with a very large time step for now (6 hours) but it still is taking a lot of time
That was discussed with Jesse before and he is aware of a long time of the run, and we requested an enhancement for run time since the same model takes around 2-3 minutes max. when we do run in InfoWorks.
The run is working in other simulation time; yes it takes longer but it does run, the issue is only during 24 hours run and that is why we posted here.
The model is likely encountering extremely unstable conditions at the time that the failure occurs, or an unexpected condition is occurring (such as overflow just starting to occur in a case where there is no downstream gutter) only at a time later on in the simulation.
This model has an unusual configuration of catchbasin connectivity that is unlikely to match the real world conditions, and instability may be occurring in the junction of a large number of conduits.
While we work on troubleshooting this, please confirm the scenario to compute and any other changes we need to make. The scenario name seen in your screenshot is using a calculation option set that is set to run only for 12 hours.
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Hello Jesse,
Jesse Dringoli said:is occurring (such as overflow just starting to occur in a case where there is no downstream gutter) only at a time later on in the simulation.
Yes that if the error occurs in all time simulation, but try to run for 2 hours (for example) the model completes the simulation; however it does not work for 24 hours.
Jesse Dringoli said:This model has an unusual configuration of catchbasin connectivity that is unlikely to match the real world conditions
would you please elaborate what is not match the reality?
Jesse Dringoli said: please confirm the scenario to compute and any other changes we need to make
Here are the screenshots I am working on, please note all the same and as I mentioned I am facing the issue in the 24 hours.
PS: just would pay your attention to the time it takes the run and would like to remind you about that, hope the new release enhances that, by the way; in UAE all other engineering companies suffering from the time it takes especially because the new standard is to do the model with inlets (that the feedback when I discuss with other engineers here). we all waiting for that big enhancement for saving time, in big models for any change we are waiting a long time till the run finish to see the results, so imagine the project and how long it takes!
Thank you,
Mohamad Azzam said:Yes that if the error occurs in all time simulation, but try to run for 2 hours (for example) the model completes the simulation; however it does not work for 24 hours.
The unstable or unexpected condition likely occurs closer to 24 hours. We are looking into it.
Mohamad Azzam said:would you please elaborate what is not match the reality?
See item #4 from my reply to this thread on January 19th. You can already provided an explanation, but the way it is configured in the model might be contributing to the long run time and potential instability that is causing the model to fail. We do not know for sure yet and will get back to you.
Mohamad Azzam said:Here are the screenshots I am working on, please note all the same and as I mentioned I am facing the issue in the 24 hours.
This appears to be a different scenario than the one shown in your original screenshot. We will take a look.
Mohamad Azzam said:PS: just would pay your attention to the time it takes the run and would like to remind you about that, hope the new release enhances that, by the way; in UAE all other engineering companies suffering from the time it takes especially because the new standard is to do the model with inlets (that the feedback when I discuss with other engineers here). we all waiting for that big enhancement for saving time, in big models for any change we are waiting a long time till the run finish to see the results, so imagine the project and how long it takes!
This was reported to our Development team in March (reference # 815156) and they are still looking into it. I will pass along your remarks.
I tried several combinations of runs but anything beyond 12 hours of simulation time is still giving the same error. We have had some recent improvements in run time especially for large models using the Explicit SWMM solver. We will test your model and see if it helps and share the patch with you.
Appreciate your patience on this.
Hello Jesse/Yashodhan
We found the reason for the engine failure, in two locations the Inflow Hydrographs are entered in the wrong units, meaning instead of 30 m3/s it is actually 30 L/s and instead of 17.5 m3/s, it is 17.5 L/s. once that is corrected the model runs.
Now the issue/question is why the engine reacts to big flow by engine failure, even if the flow is huge and the pipe is small (for such flow); the model should complete the run and gives a warning/report high values?.
hope that helps in the investigation and feedback.
I'm glad to hear that you found a likely cause of the issue. As the related wiki article states, this particular error occurs when the SWMM solver encounters an extreme, unexpected situation that it is not able to handle.
So, to answer your question - with extreme overflow occurring from the mistakenly large flows, the solver may be encountering hydraulic results that are so unstable that they are not able to properly converge, producing the failure message.
With that said, I agree that it would be helpful if the program were able to identify some kind of clue for you to locate such issues, such as the element name nearby the failure. It could be that this type of diagnostic information is not possible to generate within the scope of the SWMM solver, but I have reported this to our developers for consideration in a future version (reference # 887501)
Answer Verified By: Mohamad Azzam