Validating the need for automatic calibration

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A prerequisite for network model calibration is that overall flow balances—

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—demands, leakage, and transfers—

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—are in reasonable agreement for both the model and the real-world network for the specified time period.

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To determine the performance of the current network,

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and to validate that a calibration exercise needs to take place,

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you need to compare the simulated pressure and flows with observed values.

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The simulated values are from the results of a normal hydraulic simulation,

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and the observed values are provided by a live data configuration.

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You can then compare the live and predicted results using either graphs or grid reports.

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Observed vs Predicted Reports allow you to compare summary flow, pressure,

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or reservoir depth for all network objects of an appropriate type in the model that are linked to live data.

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Simulation Graphs allow you to produce graphs of the comparison between observed

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and predicted data for all the selected objects of appropriate type that are linked to live data.

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For this exercise, you will produce an observed versus predicted report.

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Begin by running a normal hydraulic simulation.

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Create a new Run Group object.

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In the Model Group, right-click the Calibration Model model group and select New > Run Group.

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Then, right-click the new run group and select New > Run from the flyout.

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The Schedule Hydraulic Run dialog opens.

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In the Title field, type a name for the run.

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In this example, “Normal Run” is entered.

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Check the box next to Experimental.

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Then, from the Model Group, drag and drop the Calibration network into the Network panel in the dialog.

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The Control and Demand Diagram panels populate as well.

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Click Save, and then Run.

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Next, to produce the observed versus simulated grid,

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double click on the Cal Control simulation results, then expand the Results menu and select Grid reports,

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and then from the flyout, select Observed vs predicted.

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The Grid Report (Observed vs Predicted) dialog box appears.

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From the Model Group, drag and drop the Normal Run simulation into the Sim panel,

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and then drag and drop the live data configuration into the Live Data Configuration panel.

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Under Options, enable Pressure, and then click Produce Grid.

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A table appears, providing some values and a verdict for each point in the network that has a live data pressure feed associated with it.

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In this example, you can see that three points have a fair verdict;

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therefore, running the automatic calibration module may improve the performance.