open TELEMAC-MASCARET The mathematically superior suite of solvers

Dear Jean-Philippe,
I strongly recommend you to always perform internal, fully coupling between both modules Telemac-2D and Sisyphe. This is physically more realistic than the chaining method because the hydrodynamics is updated after iteration, as is done also for the bed. By default, the bed evolution is updated after one iteration, but you can control also the coupling period.
Many examples can be found in the directory validation for the v6p2 version.

all the best,
pablo

Thank you Pablo for your reply,

The reason why I asked you this question is that I will need to develop a sort of vegetation growth model that I will have to couple with the hydro-morphodynamic model for tidal marshes. The problem is that typically, vegetation growth depicts time scales for its dynamics which are different from time scales for hydro and morphodynamics of tidal marshes. To give you a sort of schematic view: while hydrodynamics may have very short time scale (tidal scale) and morphodynamics pretty long (annual scale), vegetation dynamics can be situated in between (seasonal scale), and also has several other temporal scale. So, if I decide to go with the internal coupling, and say, choose a morphological factor (i.e. coupling period) representative of the time scale for the morphodynamics (annual scale), I may not be able to picture the vegetation dynamics.

This is why I wanted to get details about this chaining method, and especially to know if we can, using this latter technique, do the coupling automatically or if the coupling is made manually. Another way would be to define this vegetation growth as a module instead of feeding this sub-model in the morphodynamic model, but I am not sure if this is a possibility.

Do you have any recommandation on how to carry out this problem of multiple characteristic time scale ?

Thank you for your reply.

Jean-Philippe

Dear Jean-Phillipe,
your problem looks very interesting! For your case, you can try:
(1) running a 'chained method': that is, providing your previously computed hydrodynamics field to Sisyphe by using the keyword: FICHIER HYDRODYNAMIQUE = 'name of t2d the file' and running Sisyphe as stand-alone. In this case the morphodynamics will be modified at each hydrodynamic time step, but be aware that the flow variables won't be updated as does in the internal coupling way (again, I don't like this approach...).
(2) running the internal coupling and using the following keyword in the Telemac steering file: COUPLING PERIOD FOR SISYPHE. In this way, will have the control to update your morphodynamics as you wish. Probably, a sensitivity analysis will be necessary to see the influence of your results to this parameter.

I hope this helps,

please take us informed

all the best,

Pablo