open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I'm trying to minimize numerical diffusion effects on tracers by using quadratic discretization for the tracers by setting :
DISCRETIZATIONS IN SPACE = 11;11;13 or 11;11;17
but I have the following error message :
VECTOS (BIEF) : VECTEUR NON PREVU : MASVEC
POUR IELM1 = 13
Is it an inconsistency with other parameters of my steering file or is these case not implemented yet ?

Regards,
Laurent Leballeur

Hello Laurent

Space discretization of type 13 is often chosen for velocity (with type 12 also) in order to improve mainly the stability issues not to decrease the numerical diffusion. This can be assimilated as a kind of LBB condition (that not exist for shallow water equations). Even though, these choices can decrease the diffusion, since they are more accurate, the increase of CPU time and memory occupation make them less popular for Telemac users.
Moreover, there are some advection schemes that are not implemented for quasi-bubble(12) and quadratic (13) elements.
The best way to decrease the numerical diffusion is to use the numerical schemes
- the LIPS scheme (release V7P1)
- the ERIA scheme (release V7P2)
- The weak characteristics (release V7P0 and later)
and to refine the mesh in a reasonable way.

I hope that this helps
with my best regards

Riadh

Ok, thank you for the explanations and for your advice!

Best regards,
Laurent Leballeur