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Dear all,

I use telemac2d to generate turbulent velocity fields. Then I want to use that fields to simulate advection-diffusion equation with turbulent diffusion, and would like to ask you for advise how to do that. I have two ideas, but not sure if they work:
1. In telemac2d it is possible to activate tracer transport. However, as I understand from manual, that will use constant diffusion, and I don't know how to make it turbulent.
2. Is it possible to configure Sisyphe to solve pure advection-diffusion equation with turbulent diffusion but without any effects of sediments etc. If yes, if there is some example or tutorial.
3. Any other ways how to solve advection-diffusion equation?

Best regards,
Mike

Hello,

Turbulent diffusion is always taken into account for tracers, and molecular diffusion is simply added (and we shall correct the manual if it is not clear enough...). This probably cancels the two other questions...

With best regards,

Jean-Michel Hervouet

Thank you Jean-Michel for your complete answer.

I'm also wondering if there are some options (for .cas file or other) to control turbulent diffusion of tracer and if there is some description of the way it is implemented etc.?

Best regards,
Mike

Hello,

No specific parameters to control diffusion of tracers, except the classical numerical parameters like mass-lumping. You can see in subroutine telemac2d.f after header 'COMPUTES DYNAMIC VISCOSITY' how the different turbulence models are treated by a call to a specific subroutine. Then for tracers it is very simple, every tracer ITRAC has its own diffusivity VISCT%ADR(ITRAC)%P (a BIEF_OBJ structure, so add %R to find the double precision values) and so far it is the turbulent viscosity + the molecular diffusivity, so the same for every tracer, but this could be changed at this level without problem.

With best regards,

Jean-Michel Hervouet