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Dear all,

I am simulating the case of a real river with t2d-sisyphe coupled simulation. However, the results are not very satisfactory. The bed evolution is excessively high at some mesh. Also, in the curved part of the river, erosion should have happened in the outer bend but the result shows erosion in the inner bend.

When I used the same set-up for experimental channels, the result was good.

I tried with different mesh size but it didn't improve.

I had posted a similar question in the forum some weeks ago. The link is below,

www.opentelemac.org/index.php/kunena/17-...ver-non-erodable-bed

Is it the problem with the boundary condition or sisyphe setting. the input files are attached below.

In the experimental simulation, I have no sediment supply so I used the following setting for the boundary condition,

4 5 5 0.000 0.000 0.000 0.000 5 0.000 0.000 0.000 5355 1 # Inflow

I used the same setting for the real river case also. But in the case of a real river, the equilibrium sediment should be continued with the inflow discharge.
I am not sure how to incorporate that part in the boundary file.

If anyone can suggest, I would be very thankful.

Thank you in advance.

Hello,
First to all, one suggestion: try to clean/organize a bit better your sis steering file. There are some keywords, like HIDING FACTOR FORMULA, are useless for your case (you're dealing with constant sediment distribution).
Please also be aware that the value of RATIO BETWEEN SKIN FRICTION AND MEAN DIAMETER can have a deep impact on the computation of the solid discharge.
I'd also take a careful look to the parameterisations that you're using for slope effects and secondary flows. Please take a look to the manual, there is a nice description on that there.
Come back to us again if you have additional questions.
Best wishes,
Pablo

Dear Pablo,

Thank you for your valuable suggestions. I will have a close look at it and share the results.

One final thing I wanted to confirm is the boundary condition.

The boundary flag for 1) no sediment supply and 2) equilibrium bed load discharge are the same?

4 5 5 0.000 0.000 0.000 0.000 5 0.000 0.000 0.000 5355 1 # Inflow
This one I used for no sediment supply case and worked fine.

But when I used the same for the real river case, the results were not good.

Can you please suggest on this issue?

Thank you.

Regards.,
Saroj