open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all,

Little oddity which I can't seem to get under: my free surface shows no change as I alter roughness coefficients. I'm using option 4, Manning's n, on a fluvial environment with two flow boundaries.

Previous runs did show changes to the free surface with roughness coefficients, and my *.cas file (attached) has changed very little between my previous runs and my current one. However, for example, currently runs with n = 0.06 and runs = 0.1 have exactly the same free surface. My boundary conditions are the same as previous runs also (inlet:discharge and free height [455]; outlet: prescribed height [544]).

The largest change has been in my mesh: I used the kriging method to refine my topographical data and thus reduce my CPU time and time taken to converge. However, as far as I'm aware, mesh refinement affects accuracy/CPU time/convergence. How could this result in an unchanging free surface, or am I missing something?

Thanks in advance!