Create transients from junction demand changes

Any referenced datasets can be downloaded from "Module downloads" in the module overview.

Video quiz

Required for course completion

In InfoSurge Pro, when using junction demand changes to create transients, you can view the results of a surge analysis in which dialog?

(Select one)
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Step-by-step guide

InfoSurge Pro allows hydraulic transients to be created by providing a curve to alter pump and valve operations, as well as junction demand changes. Then, the simulation results from different operational conditions can be compared. In this example, transients are created from junction demand changes.

  1. Double-click the desired project .aprx file to open ArcGIS Pro.
  2. Click the InfoWater Pro tab to open the InfoWater Pro ribbon.
  3. In the Project panel, click Initialize.
  4. From the Model Explorer, select Pump Operation Change.

The Model Explorer, with the Pump Operation Change button selected and called out with a red arrow.

  1. In the Speed/Wicket Gate Change Data dialog box, click Purge to remove all previously entered settings.

The Speed/Wicket Gate Change Data dialog box with the Purge button highlighted in red.

Next, create a curve to describe the junction demand over time. For this example, use Junction 23.

  1. From the map, zoom to and select Junction 23.
  2. From the Model Explorer, click Demand Change.

Junction 23 selected and highlighted in red in the model, and in the Model Explorer, the Demand Change button called out with a red arrow.

  1. In the Junction Demand Change Data dialog box, next to the Demand Change Curve drop-down, click Browse (…) to open the Curve dialog box.
  2. Click New to create a new junction demand change curve.
  3. In the New ID field, enter “CUR5, Junction Demand Change”.
  4. Click OK.

The Curve dialog box with the New button called out, and in the New Curve popup, a New ID of CUR5, Junction Demand Change entered, and OK selected.

  1. Click Set Rows.
  2. In the Curve popup, set the value to 3.
  3. Click OK.

The Curve dialog box with the Set Rows button called out, and in the Curve popup, a value of 3 entered, and OK selected.

In the table, enter the following values in the X-axis column (time in seconds):

  1. In row 1, enter 0.00.
  2. In row 2, enter 2.00.
  3. In row 3, enter 3.00.

Enter the following values in the Y-axis column (demand in gallons per minute):

  1. In row 1, enter 150.00.
  2. In row 2, enter 150.00.
  3. In row 3, enter 1150.00.

Note that the updated graph indicates that after the first two seconds, the demand will increase from 150 to 1150 gallons per minute in one second. Such a demand increase may indicate fire flow.

In the Curve dialog box, the updated graph with new X and Y values added to the three rows.

  1. Click OK.
  2. In the remaining dialog box, select Create.

A surge analysis can now be performed.

  1. From the Model Explorer, click the Run Manager button.
  2. In the Run Manager dialog box, click the Run button to perform a surge analysis.

In the Model Explorer, the Run Manager button called out with a red arrow, and in the Run Manager, the Run button also called out.

  1. Click OK to close the Run Manager.
  2. From the ribbon, View panel, click Report Manager.
  3. In the Report Manager dialog box, click New.
  4. In the Output Report/Graph dialog box, under Available Output Sources, make sure *Active*.Surge is selected.
  5. From the Graph Report tab, pick Surge Node Graph.
  6. Click Open.

In the background, the Report Manager with New called out, and in the Output Report/Graph dialog box, *Active*.Surge and Surge Node Graph selected and highlighted in red.

  1. From the map, select Junction 23 to view its pressure profile during the transient event.

The Report Manager displaying the pressure profile for Node 23 during the transient event.

  1. Close the Report Manager.

Next, run a surge analysis with a long junction demand change time.

  1. From the map, select Junction 23 again.
  2. From the Model Explorer, click Demand Change to open the Junction Demand Change Data dialog box.
  3. Next to the Demand Change Curve field, click Browse (…) to open the Curve dialog box.
  4. With the CUR5 curve ID selected, in the X-column, change the value in the third row to 12.00.

The Curve dialog box, with the CUR5 curve ID selected and highlighted in red, and on the Curve Type tab, the X value for row 3 set to 12, also highlighted in red.

This increases the demand change time from 1 to 10 seconds.

  1. Click OK to close the dialog box.
  2. In the Junction Demand Change Data dialog box, click Update.
  3. From the Model Explorer, click the Run Manager button.
  4. In the Run Manager, click Run to perform a surge analysis.
  5. Click OK to close the Run Manager.
  6. From the ribbon, View panel, click Report Manager.
  7. From the Report Manager toolbar, click Refresh All.

In the Report Manager, the Refresh All button called out, and the updated pressure profile for Node 23 showing a reduced pressure surge.

While there is still a transient event, allowing a slower rate of demand increase greatly reduce the pressure surge.

  1. Close the Report Manager.
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