Any referenced datasets can be downloaded from "Module downloads" in the module overview.
Transcript
00:03
Before diving into a project.
00:05
It is helpful to set some simulation options to adjust facets
00:08
of a model prior to running a trial or a simulation.
00:13
For example,
00:14
simulation options can be set for hydraulics and convergence
00:17
criteria and are usually associated with specific scenarios.
00:22
You can access the simulation options dialog box from the model explorer.
00:27
If it is not already opened on the info water pro ribbon
00:31
view panel, click model explorer
00:34
from the operations tab expand simulation options,
00:38
right, click the option you want
00:40
and then click edit.
00:43
If you have not added any new simulation options,
00:46
then base base simulation options is the only available choice.
00:51
You can read more about all the settings and options in the simulation options.
00:55
Dialog box in the info water pro help documentation online
00:59
at help dot in avis
01:01
dot com slash display slash info, water pro slash simulation plus
01:06
options.
01:08
There are however a few convergence settings to get you started.
01:13
The convergence options set the conditions
01:15
under which the hydraulic solver is terminated
01:18
in the general tab convergence criteria group.
01:22
Use maximum trials to set the maximum
01:24
number of iterations of the global gradient algorithm
01:28
used to solve the nonlinear hydraulic equations
01:31
for each time step of the simulation.
01:34
The suggested value is 40
01:36
a more complex system may require more trials but no more than 200 is suggested
01:43
if sensible convergence criteria cannot be met in 100 or 200 iterations,
01:48
the model may not be solvable in its current state.
01:52
When that occurs.
01:53
It is likely that there are data input
01:56
or connectivity issues that need to be resolved.
01:59
Once any issues are resolved, you can run additional trials.
02:04
A setting related to maximum trials is relative flow error which can determine
02:09
whether the hydraulic solver has found a satisfactory solution to the equations.
02:14
The relative flow error is the ratio between
02:17
the change in the estimates of flow between
02:19
the last two iterations of the algorithm and
02:22
the total aggregated flow in the network.
02:25
If this error is smaller than or equal to the selected value,
02:29
the simulation ends for that time step.
02:32
The suggested value is 0.10 point 1%.
02:39
A smaller value provides a more accurate
02:41
solution but usually requires more trials.
02:44
Thus increasing runtime,
02:47
a larger value results in less
02:48
accurate solutions and likely requires fewer iterations
02:53
on the advanced tab.
02:55
There are some extra settings to tweak if
02:57
there are any issues while running a simulation.
02:60
If everything runs fine, then you typically do not need to change these values.
03:05
The relaxation factor is a setting for determining the
03:08
new solution or flow rate at each iteration.
03:12
If you have convergence issues running a simulation,
03:15
consider changing the relaxation factor to 0.6.
03:19
This makes the engine a little slower to solve but still maintains accuracy.
03:25
The final setting to highlight is the damping limit.
03:28
The default is zero which indicates that no damping should be used.
03:32
And that status checks on control valves are made at every iteration.
03:37
Damping might be needed on networks that have trouble converging.
03:40
In which case, a limit of 0.1 is suggested
03:45
that's 1/10 of the relative flow error value that you set in the general tab
03:50
as a reminder,
03:51
check out the info water pro help documentation for
03:54
more information on these and the other simulation options.
00:03
Before diving into a project.
00:05
It is helpful to set some simulation options to adjust facets
00:08
of a model prior to running a trial or a simulation.
00:13
For example,
00:14
simulation options can be set for hydraulics and convergence
00:17
criteria and are usually associated with specific scenarios.
00:22
You can access the simulation options dialog box from the model explorer.
00:27
If it is not already opened on the info water pro ribbon
00:31
view panel, click model explorer
00:34
from the operations tab expand simulation options,
00:38
right, click the option you want
00:40
and then click edit.
00:43
If you have not added any new simulation options,
00:46
then base base simulation options is the only available choice.
00:51
You can read more about all the settings and options in the simulation options.
00:55
Dialog box in the info water pro help documentation online
00:59
at help dot in avis
01:01
dot com slash display slash info, water pro slash simulation plus
01:06
options.
01:08
There are however a few convergence settings to get you started.
01:13
The convergence options set the conditions
01:15
under which the hydraulic solver is terminated
01:18
in the general tab convergence criteria group.
01:22
Use maximum trials to set the maximum
01:24
number of iterations of the global gradient algorithm
01:28
used to solve the nonlinear hydraulic equations
01:31
for each time step of the simulation.
01:34
The suggested value is 40
01:36
a more complex system may require more trials but no more than 200 is suggested
01:43
if sensible convergence criteria cannot be met in 100 or 200 iterations,
01:48
the model may not be solvable in its current state.
01:52
When that occurs.
01:53
It is likely that there are data input
01:56
or connectivity issues that need to be resolved.
01:59
Once any issues are resolved, you can run additional trials.
02:04
A setting related to maximum trials is relative flow error which can determine
02:09
whether the hydraulic solver has found a satisfactory solution to the equations.
02:14
The relative flow error is the ratio between
02:17
the change in the estimates of flow between
02:19
the last two iterations of the algorithm and
02:22
the total aggregated flow in the network.
02:25
If this error is smaller than or equal to the selected value,
02:29
the simulation ends for that time step.
02:32
The suggested value is 0.10 point 1%.
02:39
A smaller value provides a more accurate
02:41
solution but usually requires more trials.
02:44
Thus increasing runtime,
02:47
a larger value results in less
02:48
accurate solutions and likely requires fewer iterations
02:53
on the advanced tab.
02:55
There are some extra settings to tweak if
02:57
there are any issues while running a simulation.
02:60
If everything runs fine, then you typically do not need to change these values.
03:05
The relaxation factor is a setting for determining the
03:08
new solution or flow rate at each iteration.
03:12
If you have convergence issues running a simulation,
03:15
consider changing the relaxation factor to 0.6.
03:19
This makes the engine a little slower to solve but still maintains accuracy.
03:25
The final setting to highlight is the damping limit.
03:28
The default is zero which indicates that no damping should be used.
03:32
And that status checks on control valves are made at every iteration.
03:37
Damping might be needed on networks that have trouble converging.
03:40
In which case, a limit of 0.1 is suggested
03:45
that's 1/10 of the relative flow error value that you set in the general tab
03:50
as a reminder,
03:51
check out the info water pro help documentation for
03:54
more information on these and the other simulation options.
Required for course completion
Before working on a project, set the simulation options for hydraulics and convergence criteria.
The Relative Flow Error determines whether the hydraulic solver has found a satisfactory solution to the equations and is the ratio between the change in the estimates of flow between the last two iterations of the algorithm, and the total aggregated flow in the network. If this error is smaller than or equal to the selected value, the simulation ends for that time step. The suggested value is 0.001 (0.1%).
The default Damping Limit is 0, which indicates that no damping should be used, and that status checks on control valves are made at every iteration. On networks that have trouble converging, a limit of 0.01 is suggested.
