Setting up the simulation
A simulation of a model corresponds to a solver and its intrinsic parameters. Here, we are dealing with a TELEMAC 2D simulation for which we need to specify:
- The time step of the simulation
- The initial conditions
- The numerical scheme (finite elements or finite volumes) and any associated parameters.
For the definition of initial conditions, there are several options:
- Fix a constant water level with zero velocity over the entire domain
- Use the result of another simulation of the same model
- Define the water level with zero velocity based on an interpolation line over the entire domain.
We will use this last solution here. Even though almost the entire model is “dry” at startup, we want the upstream section to be “wet” at startup at the location of the artificial depression. On the other hand, downstream, it is recommended to start with a level equal to the constant level we have set. Given the slope, the upstream level is about 10 m above the downstream level. Therefore, we cannot use a constant level over the entire model.
The principle of the interpolation line is explained here. By placing this interpolation line in a judicious manner and setting the value of the downstream water level on one side and a water level that allows “filling without overflowing” the artificial depression on the other side, we will have our desired initial conditions upstream and downstream.
The time window corresponds to the start and end dates/times. It can be defined either automatically based on the boundary conditions or directly by the user.
In our case, the hydrograph from the Hub’Eau server indicates the occurrence of a peak on April 15, 2023. We will simulate this peak by appropriately defining the manual time window.
At this point, the model construction is complete. All that remains is the simulation, which will only take a few minutes.