When we close valve, it should make velocity in downstream is equal zero and total volume change, but all downstream not changed except a pipe have assign valve and total volume is too.
It so difficult to understood, please help us!
Hello,
I see that you also created a service request for this issue. If it is okay with you, we will keep the conversation in the forums so that other people have a chance for add input as well.
In order to look into this, it will be useful to see a copy of the model. There are two options for sharing your model files on BE Communities. If you would like the files to be visible to other members, compress the files into a zip file and upload them as an attachment using the ‘Advanced Reply editor’ before posting. If your data is confidential, you can follow the instructions in the link below to send it to us via Bentley Sharefile. Files uploaded to Sharefile can only be viewed by Bentley.
communities.bentley.com/.../bentleysecurefilesupload.aspx
If you upload the model to the Sharefile site, please post a message here so that we know that it is available.
Also, please let us know where the issue is that you are seeing, so we will be able to quickly assess the issue. Thank you.
Regards,
Scott Kampa
Bentley Technical Support
Make sure you aren't disconnecting any fixed demands (non pressure-dependent) from a source (tank or reservoir) otherwise they'll pass right through the closed valve and you'll get a red user notification about it.
You might also want to take a look at our Criticality tool.
communities.bentley.com/.../running-a-criticality-analysis.aspx
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
I'm tried some radom network simple and complex. It show some red notification when the valve was close, but the value in downstream not change that discrepancy when compare with real system.
Yes, in a real system, if you close off a demand, it will drop to zero. However in WaterCAD/WaterGEMS, when you enter a demand, you are telling the model that it needs to satisfy that demand no matter what. This is why you get the red notification, which mentions that results will be compromised. The demand will still be satisfied. In order to get accurate results, you need to either remove the demands in conjunction with closing them off with the valves, or use the Pressure Dependent Demand (PDD) feature. With PDD, if the pressure drops to zero when closing the valve, the demand will drop to zero.
With that said, it might help if you can provide some background about what you are trying to achieve. If you just want to see what elements are effected from an outage, you might be able to use the Criticality tool that I previously mentioned.
I've updated the below Support Solution with this information.
communities.bentley.com/.../10506.disconnected-demand-nodes-user-notification-when-computing-model.aspx
Answer Verified By: Sushma Choure