open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everybody,

I work with tomawac in v6p2 version. I make a simulation in order to represent the wave propagation. I force my model with waves which are these parameters:
Hs =1.5 m et Tp = 11.5s.

Also i put in my steering files these keywords:
INITIAL SIGNIFICANT WAVE HEIGHT = 1.5
BOUNDARY SIGNIFICANT WAVE HEIGHT = 1.5

My simulation runs during 500s.I should see a lot of waves. However i have one wave in my domain. Behind the wave, my sea level don't move as if my domain lost the water.





I try to change different parameters like:
- TYPE OF BOUNDARY DIRECTIONAL SPECTRUM
- BOUNDARY DIRECTIONAL SPREAD
- INITIAL DIRECTIONAL SPREAD
- NUMBER OF BREAKING TIME STEPS
But these modifications have not an influence on my results.
I post this topic in order to know if someone can look my steering file or has an idea on my bad propagation.





Regards
Florian

I think that my last post was not clear.

My simulation starts and i can see a variation of the Hs. The wave propagates to the coast where there is the wave breaking.
After, the simulation continues to run but there is no longer wave propagation. Why?
You can see it in this vidéo.





Florian

It seems that you have a problem with your boundary conditions : please check the boundary conditions types in your boundary conditions file : if you put wave absorbtion on the boundary where you actually want to impose the waves that will propagate, it will not work.
Moreover, if you want to see the propagation of a spectrum with 1,5 m significant wave height (you talk here about "one" wave but in Tomawac you simulate a wave spectrum!), you should rather put a smaller inital significant wave height.

Elodie

Elodie,

Thanks for your help,




As you can see here, i define my boundary conditions with these parameters.
I impose the waves on the 'South Boundary' which is defined by "5" in my boundary condition file. The others boundaries are defined by a "2" in my boundary condition file. Am I rigth?

I used the post "Tomawac coupled with T2D" in which you talked about these boundary conditions parameters with Romain_D ( #7493).

Regards
Florian

My conlim file

This seems ok in this graphic, but I cannot check that the nodes where you impose the conditions are the right ones.

Did you actually check that the Hs at your south boundary has the value you want to impose?

Did you try with a smaller initial significant wave height to better see the effect of your boundary condition?

Elodie

As you said me, i checked my geometry file and my boundary condition file and i found an error.
Some points which are in my boundary condition files were not on the boundary in my geometry file. I correct it and i wait the results.

I test with a smaller initial significant wave height ( =0.5).

When i see my results, it seems that i have the same propagation with just one wave







Florian

Since the beginning, i am wrong because i thought that tomawac allowed us to see the wave propagation and not a wave spectrum.
May be my questins are stupid:

Also, for each simulation i have one spectrum or i can show a lot of spectrums during the same simulation?

Can we see the contributions of the wave breaking? the contributions of the whitecapping?

Despite the fact i read the manual, i can not to see the real impacts when i modify the number of breaking time steps. Have you got more informations aboout the influence of this parameter?

Regards
Florian

Tomawac models the evolution of the variance density directional spectrum.

Whitecapping dissipation and dissipation through bathymetric breaking can be taken into account.

Please read the TOMAWAC manual, all these aspects are described : you will then have a better idea about what is a spectral wave model.

About the number of breaking time steps, you need to do sub-iterations for the breaking dissipation when your bathymetric gradient is high or your time step is not small enough.

Elodie

I already read the manual but apparently somethings were not clear.
But i don't understand why, when i make a tomawac simulation during 86400 s, i have a Hm0 variation during 1500 s and nothing after. I don't see where the explication of my problem....

I make a lot of tests in changing one parameter in each test but i don't find this explication