open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all!

I would like to know if someone has already simulated the propagation of a sediment flume entering the model by mean of a source with a given sediment concentration. I have tested this once in the past, in a rather complex model with locally high velocities and did not manage to have it running properly.

Any feedback / tips on that topic would be highly appreciated!

Thank you in advance,

Best regards
PL

Hi all!

Does someone have any idea on that topic?

Thank you in advance!
PL

Hi all again!

This question is coming back on my table at the moment and I am wondering is someone has already done such a simulation. More precisely, what I need to do is to model dispersion of sediments during dredging / removal operations. I was thinking of using a flow source with a given sediment concentration.

There is maybe information about similar thing already available somewhere here? I did not take the time to go through all the material and code. Sorry for that.

Thanks in advance!

Best regards
PL

Hi PL,
I don't much have experience for this kind of model in T3D but, without knowing about your case, I'd say that probably T3D can do the job. Depending on your configuration, you can impose an inflow boundary condition with a time-varying sediment concentration.
Special care should be put on the choice of the numerical scheme for the solution of the ADE (scheme 14 for example), as well as the choice of the turbulence model.

Please keep us informed about this.

Best wishes,

Pablo

Hi Pablo,

Thank you for your reply.

The aim is to model sediment dispersion during dredging operations so the suspended sand is supposed to be lifted from the bottom from within the model. I was therefore wondering to use a source located at an interior node. A (lateral or island) boundary would not work.
Do you think that I could do that with a source? Otherwise I can think of programming such a thing if it is not too complicated (lack of time...) and with some guidance.

Unless I am wrong, T3D can only handle one sediment diameter size unlike T2D-SISYPHE where it is possible to have several classes. Right?

Thanks in advance!

Best regards
PL

Hi Pablo,

Another quick question: does T3D offer the possibility to correct the fluid viscosity with high sediment concentrations?

Thanks in advance!
PL

Hi PL,
Again, I'm not an expert on T3D but I'll try to give some hints:
* the injection of a tracer by using a source can be a good solution to explore.
* Unless I am wrong, T3D can only handle one sediment diameter size unlike T2D-SISYPHE where it is possible to have several classes. -> yes you're right.
* does T3D offer the possibility to correct the fluid viscosity with high sediment concentrations?
I think it could be done by modifying some subroutines, take a look for example visclm. The link below has some interesting and simple models to do that:
dspace.library.uu.nl/bitstream/handle/18...E7D955ED7?sequence=4

I hope it helps,

Pablo

Hi Pablo,

I just looked at telemac3d.f and found some comments from 2014 that some structures have been changed to handle two sediment classes. Can it be two classes in the sense of two sediment fractions?

Thank you a lot for the reference, the models look simple indeed. Do you have the reference of the whole publication?

Best regards
PL

Hello,
This has been done to deal with mixed sediments: one class sand, one class mud.

cheers

pablo

Hi again,

Just a quick feedback: I tested to release sediment via a source in a simple flume model and it seems to work fine.

I will see to also test a density function to account for sediment concentration in water.

Best regards
PL