Hello guys.I have a complete water distribution system.The main challenge I am facing is how to meet the demands at specified nodes after running a criticality analysis tool.Can you guys please provide insights and assist me so that the model above can run successfully.I have set up measures and controls so that the tank will never get empty.After doing a criticality analysis on the model the hydraulic engine outputs unreasonable results.I think my question is, after running the criticality analysis(by unchecking the check valve option) and understanding which segments are facing outages then what next?Is there a way that I can incorporate during the design in order to avoid disconnection of certain segments due to demand shortfalls? I have worked on setting up new calculation options for the engine but still, I get unexpected results when I look at my flex table.
Please note that I don't want to use Pressure Dependent Demand or emitter coefficients and instead I only want to work in Steady state mode with fixed demands as they are.None of the elements is disconnected from the main model as seen in the network navigator toolbar.
Here are some links that may help you.
Thank you, Tom Walski, for getting in touch.Can you please give me a direct lead to the solution.I think my question is...after understanding which parts of my network are facing outages; that is after doing criticality analysis and segmentation to understand which segments have been disconnected due to demand shortfall then what should I do to avoid that.How do I work around with this Isolation valves or something of the sort to allow flow to this nodes without altering my demand so that I can achieve reasonable results?I don't want to use PDD or emitter coefficients.I only wanted to work with fixed demand in the Steady state.Thank you once more and sorry for asking many questions.I hope am not bothering you that much.Please have a look at the attached network I am confident it doesn't have any errors.All the controls have been set straight with none of the elements disconnected from the main network
I would recommend review the WaterGEMS Help topic called "Criticality Results," which prove a good resource for the questions you have. This talks about how to review the results from criticality from a number of different analysis types, including cases where PDD are not used. You can find this Help topic by going to File > Help > WaterGEMS Help (in CONNECT Edition) or Help > WaterGEMS Help (in V8i). Choose the Search tab and search for "Criticality Results."
To add to Tom and Scott's reply - I see that you have posted a file, but it is only the .WTG file. The .SQLITE file would be needed in order to open the file. If you are using CONNECT Edition Update 1, you can go to File > Save to Package.
If you are encountering a specific error or issue with Criticality, please elaborate on what you are seeing.
If you are asking for general advice on what to do after a criticality analysis to improve things, please elaborate on a specific challenge you are having. For example are you seeing a large system shortfall when a certain segment is out of service, but do not know what to do to prevent such a large shortfall? This may largely a matter of engineering judgment. For example there may be a trade-off analysis, comparing the cost to loop the system in such a way to avoid the shortfall when the segment is out of service, compared to the benefit and chance that the segment will be out of service. If the segment in question in the one just downstream of your main pump station for example, it may be very costly to mitigate this, as it may involve installing a backup pump station. In other case, the "solution" to high demand shortfall may be to add a loop; piping that provides another path for flow, to go around the segment that is out of service.
You may find further useful engineering advice in the book Advanced Water Distribution Modeling and Management
Jesse DringoliTechnical Support Manager, OpenFlows ProductsBentley Communities Site AdministratorBentley Systems, Inc.
Hello, for a clear and precise elaboration, please check the attached file6237.watercad.zip.
If I were to design the same system in an excel sheet with defined formulas I will get results.
My question is can I be able to successfully run the model above and still meet all the demand in all nodes?,and still be able to get the results without encountering any errors.
Hello, in order to understand my case better please check the attached3755.watercad.zip.