An extended period calibration consists of correlating known extended period field data with an extended period simulation. What is different between an EPS and a Steady State calibration is that you are now able to enter the times at which field measurements were acquired. Thus, a model can be calibrated over a series of timesteps rather than at one "instantaneous" point in time. The EPS calibration data consist of pipe roughness, junction pressures, link flows, and tank levels. The latter three sets of information must include the time at which the field measurements were acquired. Once the modeling parameters have been specified, you are able to run the calibration simulation, review results and then write those results to any respective data set.
Specifying EPS Parameters
You can specify one or more groups in which a calibration is to be made. Click on any of the links below to learn more about each tab and its purpose during an EPS calibration.
Roughness Group - This tab allows you to specify ranges for pipe roughness coefficients during the calibration simulation.
Junction Pressures - This tab allows you to enter known field measured pressures for specific junction nodes across the distribution system. Time values must also be entered for an EPS calibration.
Pipe Flows - This tab allows you to enter known field measured flow for specific links (pipes, valves, pumps) across the distribution system. Time values must also be entered for an EPS calibration.
Tank Head/Level - This tab allows you to enter the know field levels for specified tanks across the distribution system. Time values must also be entered for an EPS calibration.
Running an EPS Calibration
To run the EPS calibration, from the Run menu, select Start. The Run tab will now be displayed in which the number of iterations can be viewed.
Once an EPS calibration simulation has been performed, click on the Run Summary tab to review output results such as overall fitness convergence and the average difference in pressure measurement, flow measurement and head measurement.
Exporting Calibration Data
If you are satisfied with the fire flow test calibration simulation, results of the pipe roughness coefficients can be exported to the pipe data set.