open TELEMAC-MASCARET The mathematically superior suite of solvers

I am trying to model coastal inundation using Telemac2D. In my study area, the bottom elevations slope gradually up towards the shoreline but there are a few port structures where the bottom elevations suddenly transition from -15m GD to +3 m GD (see BOTTOM.png). The peak tide in the imposed tidal cycle is > 3m GD and the goal is to model the flooding onshore (depths and velocities).

The user manual provides a few suggestions for domains with steep gradients in the topography:
- refine the mesh at the slope
- use keywords TREATMENT OF THE LINEAR SYSTEM = 2 and FREE SURFACE GRADIENT COMPATIBILITY = 0.9

I have implemented those suggestions and it has allowed the simulations to run to the end. However, there are irregularities in the water surface elevation at the sloping elements (see attached image with 0.02 m contour intervals).

Is there a maximum recommended slope that TELEMAC2D can handle?

Any suggestions to improve the representation of the near vertical wall in the model?

Thanks!

Hello,

You can try:

FREE SURFACE GRADIENT COMPATIBILITY : 0.

and also:

IMPLICITATION FOR VELOCITY = 1.

and a higher VELOCITY DIFFUSIVITY, of 1 m2/s for example.

I would also remove VARIABLE TIME STEP = YES and try various time steps, even with Courant numbers greater than 1.

With best regards,

Jean-Michel Hervouet

Hi,

Why don't you try defining your structure outline as boundary segments? You could avoid the near-vertical elements at the quay walls.

Here is an example:





Regards,
Costas

Hi Costas,

Thanks for the suggestion. This is what I would normally do at a structure except that the goal in this case is to model the flooding of the structures and the area onshore and therefore needs to be included in the mesh.

I am currently doing tests with Jean-Michel's suggestions.