& Construction

Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
& Manufacturing

Professional CAD/CAM tools built on Inventor and AutoCAD
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.
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.
There are some 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:
Auto-calibration offers certain benefits:
The auto-calibration method is based on a repetitive user-defined snapshot analysis that includes pressure observation points:
The algorithm used is based on common engineering practice: