WaterGEMS Darwin Calibrator how to find locations of valve closer?

Hello Yoko,

Are you trying to locate critical valves in the network and observe outage elements?

If this is the case, then you can use the Criticality Tool;

Running a Criticality Analysis

In this you can identify critical valves in your system and identify outage elements based on their closure.

If this is not what you are looking for please elaborate your query? What kind of study are you performing?

Yashodhan,

Thank you for your reply.

I am calibrating a model for a city using hydrant flow tests.

For each flowing event, I have the water levels data at the towers and how many pumps are pumping at what flow.

I have been analyzing the hydraulic grades differences and the flow differences at the hydrants between the model results and the field data.

I've looked at the pipe connectivity, demand locations of customer meters, pipe C-values, and emitter coefficients of hydrants.

At this point, I have about half of the tests matching with the field data and another half showing higher hydraulic grade in model than the field data by 16-40 feet.

I am suspecting valve closures and I would like to find out the possible locations for valve closure.

I have not used Darwin Calibrator yet, but I found an article on Bentley web site titled, 'What does it take to make automated calibration find closed valves and leaks?'

Do you recommend Criticality Tool or Darwin Calibrator for what I am trying to achieve? 

Thank you.

Yoko

Hello Yoko,

If you are using Darwin Calibrator, you may want to consider adding pipes are valves to the Status tab in the calibration study. A good reference for this is the sample file found at C:\Program Files (x86)\Bentley\WaterGEMS\Samples\Example5.wtg. This sample file includes a calibration study in Darwin Calibrator. 

When you open Darwin Calibrator, select Calibration Study - 1 and look at the Status Elements tab. Notice that a pipe is included there, with an initial status of Open. Now run "Optimized Calibration - 1" and view the results in Solution 1. If you select the Status results, you will see that Darwin Calibrator changed the status of the pipe to Closed. That means that to get the best results, Darwin Calibrator required the pipe to be closed, which may be an indication that a valve on that pipe is closed in the field.

You may want to try something like that in your model too. Note that if you include a lot of pipes or valves in the Status Elements tab, you may need to increase the Maximum Trials value in the Options tab. See the Darwin Calibrator wiki for other tips.

Regards,

Scott

Scott,

Thank you for your advice.

I will try that.

Yoko

When I look at the Example #5, hydrant flushing are set at junctions instead of hydrants.

If I set the Darwin calibration using hydrants, when it simulates multiple flow tests, would it open the hydrants instead of just adding the flow demand?

When I run manual calibration (Not using Darwin Calibrator)  with a closed hydrant with a demand vs. an open hydrant without demand, the results were significantly different and I found the latter to be a correct setting. I want to make sure that the Darwin Calibration can run multiple hydrant tests as shown in the example by opening each hydrants.

Otherwise, I can run only one hydrant test at a time with a specific physical setting, yes? Or perhaps I need to create a junction with the same elevation as hydrants and run the analysis?

Yoko