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Hello,
I am running a tsunami simulation and the free surface results on the shoreline are acceptable compared to the tide gauge measurements, but the velocities values are too low. According to field data, these values should be from 5 to 8 m/s and results show a maximum of 0.13 m/s. I have reduced the coefficient of friction but the results have not changed significantly.
Does anyone have an idea why this is happening or what other parameters I need to modify? I attached all inputs and results.
Thanks in advance.

Tomas

I couldn't share the rest of the files due to share limits so you can find them at this link:

drive.google.com/drive/folders/1bE0d0ppS...U6jlDjOS?usp=sharing

Hello,

I have not been able to download your files yet - I will try from home - but as a first comment I would highlight that are using TELEMAC-2D (depth averaged). Can I ask where your velocity data where measured from ? Is it possible that you have surface flow and a return flow within the same water column ? .. in which case you could try TELEMAC-3D (3 to 5 layers ought to be enough).

Also, if you really wish to look at the flows on dry land (with high velocities there), you probably need to switch to the Finite Volume formulation - again I have not looked at your simulation yet.

Hope this helps nonetheless,
Sébastien.

Hi Sebastien,
Thank you for your reply.
I finally sort out that the problem was the topography used to interpolate the bottom mesh of the geometry file. So, after removing values greater than 10 m, works. Now I have another issue with the free surface, though.
As you can see in the screenshots, the free surface shows weird results during the simulation in the continental part. It shows values around 10 m and never changes, despite that water depths are zero. Do you have an idea what I'm doing wrong?
Fin attached the geometry, border condition and the steering file to run it if you prefer.
Many thanks,

Tomas

Hi
Free Surface = Bottom + Water depth
In your case, free surface just show the bottom level

Regards

Hello,
Thanks for your answer, although I'm not sure what to do. So I will explain my case better.
I am simulating a tsunami and I need to check the propagation of the waves in the ocean and how the continent is flooded. So my domain has positive (mainland) and negative (seafloor) elevations.
If Free Surface = Bottom + Water Depth and an initial condition of "ELEVATION ZERO" is established, the free surface on the continent will always be the bottom and never zero. So how can I fix that on the continent the initial free surface is also zero like on the ocean? Do I need to set different boundary conditions from the coast to the rest of the continent? Should I run different simulations on the ocean and the continent?
Also, Sebastien indicated that I need to switch to the finite volume formulation, but I didn't understand what he meant.
Thanks in advance
Tomas

Free surface will never be 0 on the continent!
The main variable is the water depth (used in discretized equations to compute the solution in time) and by default, the water depth should be positive or nul.
If there is no water, there is no evolution...
Forgot to have a free surface equal to 0 on land, this is a non-sense

About Sebastien remark, he just indicate that there is différent options in Telemac. You could run computations using a finite element approach (default) or use a finite volume approach (which could be better for some simulations. This is not mandatory but could help to improve results.

Read the manuals and/or the Jean-Michel Hervouet book to have a full understanding of the capabilities of these options.

Regards

Hello,

Thank you so much for your reply, now I'm more clear about everything . It was all about confusing the concepts.
So, if I understood correctly, the variable I need to analyze to see the wave evolutions(height) in the total domain is the water depth instead of the free surface, right? It's just to be sure.
Thank you very much once again for your time in explaining it.
Cheers

Tomas

Hi
You could analyse the water depth.
You could also look the free surface only when water depth is positive (like a kind of mask)

Regards