Understanding the Flooding Simulation Engine

00:03

in info drainage. The one D two D. Analysis uses a one D simulation engine

00:08

to calculate the flows in the pipes,

00:10

manholes and other structures below the ground

00:13

in combination with the two D simulation engine

00:16

to predict flood flows across the catchment surface.

00:20

This enables the program to represent the

00:22

overflow from the sewer or channel network,

00:25

the movement of the flooded water on the surface

00:27

and the re entrance of the flooded water back into the sewer or channel network.

00:33

The one D simulation engine and the two D simulation engine runs simultaneously

00:38

during the one D two D analysis,

00:41

in order to enable dynamic coupling between the two engines.

00:45

Each simulation engine runs with its own computational time step

00:49

and the two engines sync up at regular intervals.

00:53

There are three areas in which the exchange

00:55

between the two engines can happen in info drainage

00:59

at manholes along the banks of open channels

01:03

and along the outline of stormwater controls.

01:07

The overflow can happen in one location,

01:09

while the re entrance of the flooded water can happen in a different location

01:13

depending on whether the flooded water will move on the

01:15

surface after coming out of the one D network,

01:19

there are no limits on how many locations the water can

01:21

be exchanged or how many times the water is exchanged.

01:26

So for example,

01:27

info drainage can be used to represent flooding coming out of an open channel,

01:31

then the flood waters flow on the surface to some

01:34

lower ground where the water is captured by a pond.

01:38

Eventually this pond fills up and floods itself.

01:41

The flood water flows further away following the terrain, slope and features

01:45

and it ends up near a manhole where it is captured and goes into a conduit.

01:51

Note that in this example the open channel

01:53

the pond

01:54

and the manhole did not need to be connected by the same one D. Network.

01:58

They can be connected to different outfalls.

02:02

The computation of the exchange between the one D. Network and the two D. Surface

02:06

accounts for the respective heads at the location of the possible exchange.

02:11

The flow exchanged is calculated using an orifice equation for the

02:15

manholes and a weir equation for the channel banks and pond outline

02:20

for the latter. Due to their linear nature.

02:22

The weir is split into multiple segments,

02:25

accounting for versaces in the two D mesh and

02:28

hydraulic calculations are done on each individual segment.

02:32

The one D two D analysis is typically more

02:35

computational e intensive than the regular one D only analysis

02:39

due to the extra effort of running the two D engine

02:42

and the overhead of the exchange between the two engines.

02:47

The increase in analysis time depends on factors like

02:50

the amount of water in the two D domain,

02:53

the percentage of the two D. Domain that is wet

02:56

and how many locations the water is exchanged between the two engines.

03:01

Lastly,

03:02

it is important to understand that the one D two D

03:05

analysis runs for one phase and one event at a time

Video transcript

00:03

in info drainage. The one D two D. Analysis uses a one D simulation engine

00:08

to calculate the flows in the pipes,

00:10

manholes and other structures below the ground

00:13

in combination with the two D simulation engine

00:16

to predict flood flows across the catchment surface.

00:20

This enables the program to represent the

00:22

overflow from the sewer or channel network,

00:25

the movement of the flooded water on the surface

00:27

and the re entrance of the flooded water back into the sewer or channel network.

00:33

The one D simulation engine and the two D simulation engine runs simultaneously

00:38

during the one D two D analysis,

00:41

in order to enable dynamic coupling between the two engines.

00:45

Each simulation engine runs with its own computational time step

00:49

and the two engines sync up at regular intervals.

00:53

There are three areas in which the exchange

00:55

between the two engines can happen in info drainage

00:59

at manholes along the banks of open channels

01:03

and along the outline of stormwater controls.

01:07

The overflow can happen in one location,

01:09

while the re entrance of the flooded water can happen in a different location

01:13

depending on whether the flooded water will move on the

01:15

surface after coming out of the one D network,

01:19

there are no limits on how many locations the water can

01:21

be exchanged or how many times the water is exchanged.

01:26

So for example,

01:27

info drainage can be used to represent flooding coming out of an open channel,

01:31

then the flood waters flow on the surface to some

01:34

lower ground where the water is captured by a pond.

01:38

Eventually this pond fills up and floods itself.

01:41

The flood water flows further away following the terrain, slope and features

01:45

and it ends up near a manhole where it is captured and goes into a conduit.

01:51

Note that in this example the open channel

01:53

the pond

01:54

and the manhole did not need to be connected by the same one D. Network.

01:58

They can be connected to different outfalls.

02:02

The computation of the exchange between the one D. Network and the two D. Surface

02:06

accounts for the respective heads at the location of the possible exchange.

02:11

The flow exchanged is calculated using an orifice equation for the

02:15

manholes and a weir equation for the channel banks and pond outline

02:20

for the latter. Due to their linear nature.

02:22

The weir is split into multiple segments,

02:25

accounting for versaces in the two D mesh and

02:28

hydraulic calculations are done on each individual segment.

02:32

The one D two D analysis is typically more

02:35

computational e intensive than the regular one D only analysis

02:39

due to the extra effort of running the two D engine

02:42

and the overhead of the exchange between the two engines.

02:47

The increase in analysis time depends on factors like

02:50

the amount of water in the two D domain,

02:53

the percentage of the two D. Domain that is wet

02:56

and how many locations the water is exchanged between the two engines.

03:01

Lastly,

03:02

it is important to understand that the one D two D

03:05

analysis runs for one phase and one event at a time

Video quiz

When running the 1D - 2D Analysis, in which three areas does the exchange between the 1D simulation engine and the 2D simulation engine happen in InfoDrainage?

(Select one)
Select an answer

1/1 questions left unanswered

Step-by-step:

In InfoDrainage, the 1D - 2D Analysis uses a 1D simulation engine to calculate the flows in the pipes, manholes, and other structures below the ground in combination with a 2D simulation engine to predict flood flows across the catchment surface. This enables the program to represent the overflow from the sewer or channel network; the movement of the flooded water on the surface; and the re-entrance of the flooded water back into the sewer or channel network.

The 1D - 2D Analysis uses, in combination:

  • A 1D simulation engine to calculate the flows in the pipes, manholes, and other structures below the ground.
  • A 2D simulation engine to predict flood flows across the catchment surface.

Three areas in which the exchange between the two engines can happen:

  • at manholes
  • along the banks of open channels
  • along the outline of stormwater controls

There are no limits on how many locations the water can be exchanged, or how many times the water is exchanged.

Note that in this example, the open channel, the pond, and the manhole do not need to be connected by the same 1D network; they can be connected to different outfalls.

The InfoDrainage interface, with a complete drainage model and a flooding simulation running. The Plan View shows the flooded areas in blue.

The computation of the exchange between the 1D network and the 2D surface accounts for the respective heads at the location of the possible exchange. The flow exchanged is calculated using an orifice equation for the manholes, and a weir equation for the channel banks and pond outline.

The Results Pond dialog box, showing the results of the flooding simulation in graph form, including a Flow Graph, Volume Graph, and Depth Graph.

The 1D - 2D Analysis is more computationally intensive than the 1D-only Analysis, due to the extra effort of running the 2D engine and the overhead of the exchange between the two engines.

Increase in analysis time depends on factors like:

  • amount of water in the 2D domain.
  • percentage of the 2D domain that is wet.
  • how many locations the water is exchanged between the two engines.

The InfoDrainage interface, with the Plan View in the background showing a complete drainage model and a flooding simulation with the flooded areas in blue. In front of that is a callout stating that it is important to understand that the 1D – 2D Analysis runs for one phase and one event at a time.

 

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