Introducing Automatic Calibration

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.

Video quiz

Which of the following networks would be ideal for using the Auto Calibration function in InfoWorks WS Pro?

(Select one)
Select an answer

1/1 questions left unanswered

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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