• InfoWorks WS Pro

Introducing Automatic Calibration

Describe how the automatic calibration functionality works within InfoWorks WS Pro.


00:03

InfoWorks WS Pro provides an automatic calibration facility

00:09

to help speed up work on models where friction factors have a predominant role in calibrating real-life networks.

00:16

It is especially well-suited for all-mains models,

00:19

but it is not designed for use on networks that have control mechanisms within the network that affect the pressure regime,

00:26

such as valves and pumping stations.

00:29

Head differentials caused by partially closed valves, inefficient pumps,

00:34

or incorrect PRV or PSV settings are not accounted for in the auto-calibration process.

00:41

These could cause an inappropriate pipe weighting or friction factor to be produced.

00:46

In these instances, it may be more appropriate to break down the network

00:51

into smaller zones bounded by the control mechanisms and use a fixed head as a source.

00:57

This would allow zones in which “known” causes of headloss are only due to friction factor.

01:04

A prerequisite for network model calibration is that there must be reasonable agreement between the overall flow balances—

01:13

—demands, leakage, transfers—

01:16

—over the time period in both the field and in the model.

01:20

If an accurate flow balance has not been achieved, then auto-calibration should not be used.

01:27

Auto-calibration can significantly speed up calibration and analysis work on large all-mains models,

01:34

where friction factors have a predominant hydraulic role.

01:38

It can also be useful when working with field data from loggers, telemetry systems, and SCADA,

01:45

but it is not a replacement for an experienced engineer.

01:49

The auto-calibration method is based on a repetitive user-defined snapshot analysis

01:55

that includes pressure observation points throughout the network.

01:59

Typically, a peak demand time step is used,

02:03

during which friction factors in the simulation are adjusted

02:07

until a minimum sum of differences between the model and the observed field data is reached at the observation points.

02:15

The algorithm used is based on common engineering practice

02:19

and follows simple logical steps in situations where friction coefficients are the predominant factor in network model behaviour,

02:28

which is typically in large, detailed distribution models.

02:32

The calibration simulation produces a factor by which to adjust the friction factors in a network.

02:38

Once you have carried out a calibration run, you can update the roughness values in your network using the factoring.

Video transcript

00:03

InfoWorks WS Pro provides an automatic calibration facility

00:09

to help speed up work on models where friction factors have a predominant role in calibrating real-life networks.

00:16

It is especially well-suited for all-mains models,

00:19

but it is not designed for use on networks that have control mechanisms within the network that affect the pressure regime,

00:26

such as valves and pumping stations.

00:29

Head differentials caused by partially closed valves, inefficient pumps,

00:34

or incorrect PRV or PSV settings are not accounted for in the auto-calibration process.

00:41

These could cause an inappropriate pipe weighting or friction factor to be produced.

00:46

In these instances, it may be more appropriate to break down the network

00:51

into smaller zones bounded by the control mechanisms and use a fixed head as a source.

00:57

This would allow zones in which “known” causes of headloss are only due to friction factor.

01:04

A prerequisite for network model calibration is that there must be reasonable agreement between the overall flow balances—

01:13

—demands, leakage, transfers—

01:16

—over the time period in both the field and in the model.

01:20

If an accurate flow balance has not been achieved, then auto-calibration should not be used.

01:27

Auto-calibration can significantly speed up calibration and analysis work on large all-mains models,

01:34

where friction factors have a predominant hydraulic role.

01:38

It can also be useful when working with field data from loggers, telemetry systems, and SCADA,

01:45

but it is not a replacement for an experienced engineer.

01:49

The auto-calibration method is based on a repetitive user-defined snapshot analysis

01:55

that includes pressure observation points throughout the network.

01:59

Typically, a peak demand time step is used,

02:03

during which friction factors in the simulation are adjusted

02:07

until a minimum sum of differences between the model and the observed field data is reached at the observation points.

02:15

The algorithm used is based on common engineering practice

02:19

and follows simple logical steps in situations where friction coefficients are the predominant factor in network model behaviour,

02:28

which is typically in large, detailed distribution models.

02:32

The calibration simulation produces a factor by which to adjust the friction factors in a network.

02:38

Once you have carried out a calibration run, you can update the roughness values in your network using the factoring.

InfoWorks WS Pro provides an automatic calibration facility.

A presentation slide on Automatic Calibration describes how it speeds up work on models where friction factors have a predominant role, and that it is well-suited for all-mains models, but is not for use on networks with pressure controls.

There are some elements that are not accounted for in Auto-Calibration, including partially closed valves, inefficient pumps, and incorrect PRV or PSV settings.

A presentation slide listing the elements that are not accounted for in auto-calibration, including partially closed valves, inefficient pumps, and incorrect PRV or PSV settings.

Prerequisites for network model calibration include pressure verdicts listed as Fair and Good since auto-calibration should not be used if an accurate flow balance is not achieved:

A presentation slide displays the prerequisites for network model calibration, and it shows a part of a grid report where pressure verdicts are listed as Fair and Good since auto-calibration should not be used if an accurate flow balance is not achieved.

Auto-calibration offers certain benefits:

A presentation slide about the usefulness of the Auto Calibration Utility in data loggers, telemetry systems, and SCADA.

The auto-calibration method is based on a repetitive user-defined snapshot analysis that includes pressure observation points:

A presentation slide listing the information the snapshot analysis includes, such as a peak demand time step and adjusted friction factors.

The algorithm used is based on common engineering practice:

A presentation slide listing the factors of the algorithm used during the auto calibration, where friction coefficients are the predominant factor.

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