Add 1D elements to a 2D model

1D elements can be added to any 2D model in a few simple steps. First, you need to change some Global settings and Numerical settings. Then you add the 1D elements to the schematisation and upload it as a new revision. The 3Di model that is created from this revision will include the 1D elements.

Global settings to be changed

To make the required changes to the global settings, load your schematisations and open the Global settings attribute table.

  • In the tab General, check the option Use 1D flow

  • In the tab Extra options 1D, check if the settings have the correct values

Numerical settings to be changed

Open the Numerical settings attribute table.

  • In the tab Limiters, switch the limiter_grad_1d on (set it to 1).

  • In the tab Matrix, set use_of_nested_newton to the correct value (depends on what if the 1D elements you are going to add will have open or closed cross-sections).

  • Still in the tab Matrix, set max_degree to “7: for 1D and 2D flow”

  • If you are going to use pumps, the pump_implicit_ratio (Miscellaneous tab) should normally be set to 1, unless you want to study exactly when the pump switches on or off.

  • The preissmann_slot (Miscellaneous tab) should normally not be used, i.e. set it to 0.

Adding 1D elements

After having set the global and numerical settings, you can start adding 1D features. See Editing schematisations for more information.