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Hello!

I want to model an inflow with a concentration of suspension, actually without bed load. When I started running Sisyphe(coupled with Telemac) without suspension, just bed load, everything runs well and I get reasonable results. But when I activate suspension, set in the steering file(Telemac 'tracer imposed on this boundary' and set the values in the steering file of sisyphe in 'concentration per class at boundaries' the enclosed message shows up.

I have no idea what to modify in the settings...

Another error occured when I started to vary the settings in the telemac steering file. I activated the tracer theire and out of the blue I couldn't open the editor 2D anymore and it reset my complete .conlim file.
Is this a problem of fudaa?

And my last question

My model consists of a river with it's meadows. I set the bottom friction for the bed with typical values for the sediments an the meadows with those for forest and grassland. How is the forest and grasland included in the exner equation? I mean, theoretically I would gues their would be more sediment than erosion.

Thanks in advance!!!
Sarah

Dear Sara,
some hints below...:

(I) Depending on your problem, be sure that you have these keywords in your sisyphe's steering file:
SUSPENSION = YES
EQUILIBRIUM INFLOW CONCENTRATION : YES
or CONCENTRATION PER CLASS AT BOUNDARIES = xxxx..
REFERENCE CONCENTRATION FORMULA = 3
SEDIMENT DIAMETERS = xxx
SETTLING VELOCITIES = xxx
You don't need to activate the keyword 'tracer imposed on this boundary' in the t2d steering file.

(II) post this question in the pre/post processing Forum topic

(III)
>My model consists of a river with it's meadows. I set the bottom friction for >the bed with typical values for the sediments an the meadows with those for >forest and grassland. How is the forest and grasland included in the exner >equation? I mean, theoretically I would guess their would be more sediment than erosion.

Good question and nice subject. If we take a look to the Exner's equation in their simplest form (only bedload), the influence of the vegetation impacts directly on the hydrodynamics (via the friction terms and eventually turbulence), that in turn is used to evaluate the sediment fluxes present in the Exner equation.
But in life things are in general more complicated...this is an active research topic that is being study from different space and time scales. Probably some members of the Telemac-Mascaret community can give you more details and references (by the way, this topic is in the TODO list for future research and implementation...).

All the best,

Pablo

Hey Pablo,

thank you very much for your quick answer!

About topic two and three I will ask the Pre-/Post group and the Telemac one.

Regarding to the suspension I used all the settings you wrote, but the same error occurs again in both ways(equilibrium inflow... and concentration per class...)

Maybe you could have a look at it..
Thank you!!
Best! Sarah

Just to finish the suspension problem...

I tried the same settings in the v6p1-Version of Telemac and Sisyphe and it worked... So it seems a mistake by the new version.

Bye Sarah

Hi Sarah,
could you please send me all the files to run your application?

Are you launching the simulation via the Fudaa interface or from the command line?

Many thanks,

Pablo

Hey Pablo,

I'm using the fudaa interface.
I think I would try to calculate the suspension with the older version. Or do ou think the result would be totally different?

All the best!
Sarah

Hello Sarah,
thanks for your response. The results shouldn't be different. I'd like to ask you if it is possible to have your files, beacause I'd like to see if the problem comes from a bug from Sisyphe or from the interface Fudaa that fails to launch correctly the computations.
You can send the files to This email address is being protected from spambots. You need JavaScript enabled to view it.

Many thanks,

Pablo

Hello Pablo,

I'm really sorry for my late respond. Anyway I can't send you my modell, since I can't give anybody the data.
The .cas and .conlim files are the only things I can give you.

Best,
sarah

Hi all,

I am trying to simulate coastal sediment transport using telemac2d internally coupled with Sisyphe. I’m taking into account bedload and suspended load transport.

For a first and simplest case, I am using tide levels variations as boundary conditions during 24 hours, but I’m getting weird results (great amounts of erosion and deposition). While taking a look at the hydrodynamic results, they are also weird (although they were reasonable when running Telemac2d without coupling with Sisyphe).

The results were more logical when I account only for bed load transport, so I’m thinking may be something is wrong with the suspended load parameters (and thus chose to post under this topic).

I attached the files herein. I’m using version 6.3 of Telemac under Windows 7.
Any help would be appreciated.

Thanks,
FEZAI

After some time of investigation, it turns out that I have great velocities at the upper and lower boundary conditions (taken as free boundaries). For the hydrodynamics it was ok because these high velocities occur very far from my domain of interest (and thus I intentionally enlarged the computational domain to neglect what happens at the farther boundaries).

For the sedimentological computation its seems that these velocities result in a nonsense solution.

So changing the upper and lower boundary conditions from free boundaries to closed ones avoided high velocities and seems to go better.

FEZAI.