1D river simulations - links tab

The 'Links' tab provides two sets of options:

• TUFLOW link options

• 1D River - 1D Urban link options

Currently the 2D modelling options provided only apply to linking to TUFLOW models (2D models are linked instead via the 2D Simulation form. This can be opened, if available, by going to Simulation Tab on the Flood Modeller Ribbon, clicking on “Load 1D/2D Simulations”, and then (in the Project panel) double clicking on the simulation name). The options are defined as follows:

• 2D scheme type - Select the name of the 2D scheme to link with the 1D solver. This requires additional software, i.e. purchasing of a TUFLOW license.

• 2D timestep - Timestep to be used by the 2D engine. If this is set to a negative value the timestep specified in the TUFLOW tcf file (control file) will be used. Alternatively if this is set to zero then a timestep will be calculated automatically by the 1D engine (usually half of the 1D timestep).

• Run options - Text box for entering any 2D scheme specific run options (typically command line arguments). Please refer to the appropriate 2D user guide for more information.

• 2D model control file - Click on the button to browse to the required TUFLOW control file (*.tcf).

• Perform corrective 1D timestep - Option to perform a corrective 1D timestep after, as well as before, the 2D timestep.

• Use double precision TUFLOW version - Option to utilise double precision version of TUFLOW. This option will be activated automatically if you are using the double precision version of the 1D engine.

• Synchronise HPC Timestep - option to synchronise the TUFLOW HPC timestep with that of Flood Modeller 1D, i.e. multiple (adaptive) HPC timesteps do/can occur within a Flood Modeller 1D timestep, but the "last" one in each bunch can be forced to coincide with a Flood Modeller timestep. This optimises the information exchange and can aid with stability and possibly mass conservation.