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Modelling culverts

Do you want to model culverts in Delft3D Flexible Mesh? This is the current status.

Culverts transport water below a road or dike. This option is currently being developed and implemented for 2D and 3D simulations. In the meantime, there is a workaround: adding a 1D feature using Delft3D FM 1D2D. 

The workflow involves several steps using the 1D2D Suite. Once you have installed it, open it and you will see that the GUI is very similar to the 2D3D, but with some different menu options. 

 

1.    Load your model. 

  • Open the 1D2D GUI and create a new empty project. 
  • In the ‘Project’ panel, right-click in ‘Project1’ -> ‘Import’ -> ‘Flow flexible Mesh model’ -> select the mdu-file of your model. Note that you can also import from the xml-file by selecting ‘DIMR configuration’.

2.    Create a 1D element representing your culvert.

  • In the ‘Map’ menu on top, under the ‘Network’ block, select ‘Add new pipe’ (see figure) and draw a polyline in your model from the beginning to the end of your culvert. 

3.    Add an element for connecting the 1D element to the 2D network. 

  • In the ‘Map’ menu on top, under the ‘Area’ block, select ‘Add new gully’ (see figure) and click in each of the two ends of the polyline. 

4.    Connect the 1D to the 2D network. 

  • In the ‘Map’ menu on top, under the ‘1D2D Links’ block, click on the drop-down menu, select ‘Gully-sewer’ (see figure).
  • In the ‘Map’ menu on top, under the ‘1D2D Links’ block, click on ‘Generate links’ and create a polygon that encircles the 1D element. You will see that small purple arrows appear showing the connection between grids.

5.    Export the model.

  • In the ‘Project’ panel, right-click in the FM model (not the project) -> ‘Export’ -> ‘Flow flexible Mesh model’ -> chose a location. select the mdu-file of your model. Note that you can also export the xml-file by selecting ‘DIMR configuration’.

6.    Remove storage nodes. 

  • By default, storage nodes representing manholes at the entrance of a pipe are created when creating a pipe. These are not necessary for modelling a culvert, as it is your case. For removing them, open the mdu-file in a text editor and delete the reference to the file in flag StorageNodeFile under the block [geometry]:

[geometry]
StorageNodeFile = 

7.    Modify gully properties.

  • By default, the gullies have a small dimension representing street gullies. These can be modified using flags Uniformwidth1Dstreetinlets and Uniformheight1Dstreetinlets in the [geometry] block (see manual). These flags do not appear by default, so you will have to add them. Write a large number such that it does not influence the flow. 

[geometry]
Uniformwidth1Dstreetinlets = 100
Uniformheight1Dstreetinlets = 100