open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi everyone,

I'm currently running a test simulation on Sisyphe, internally coupled with Telemac2D, in a straight channel (12km X 600m X 3m), using cohesive sediments at the bottom. The initial conditions of the simulation are uniform depth (3m) and a longitudinal slope of the free surface. The boundary conditions are prescribed discharges (450m³/s) on the upstream boundary, and fixed water level on the downstream boundary.

So, the expected result is that the bottom evolution will provide that both the longitudinal water level profile and the longitudinal bed level profile will align to each other.

Turns out that the model stops eroding when the total evolution of the bottom reaches 0.1m, doesn't matter what value for the CRITICAL SHEAR STRESS FOR EROSION I specify.

I believe it has something to do with the thickness of the bed layer, but I'm already using for the ACTIVE LAYER THICKNESS a value of 100000. I have already tested it with other values but the problem remains the same.

Can anyone give me some hints on how can I solve this problem? The steering files of this simulation are attached here.

By the way, I also have another question. When I set a value for critical erosion shear stress wich is close (but lower) than the bottom shear stress, the model calculates zero erosion. For example, I set a value of 0.2N/m² for the critical shear stress, an the bottom shear stress were about to 0.22N/m². Does anybody knows why is that?

Thanks in advance for the help.

Rodrigo Peixoto.

The steering file of the hidrodynamic model.