open TELEMAC-MASCARET The mathematically superior suite of solvers

hi, everyone
can anyone tell me which fortran file describes how to solve the tracer conservation equation? I cannot find it...I wonder is it cvtrvf.f?
Thank you!

Hello,

The subroutine that does advection-diffusion for every tracer is cvdftr.f, it includes many methods and options, e.g. it can call cvtrvf.f which deals with distributive schemes. The equation solved is given in the header, and the explicit source term is here called SM, the implicit source term is called SMI.

To understand what explicit source term you have to set, it suffices to know that if F is the tracer, the equation solved is DF/DT + other terms = SM.
With best regards,

Jean-Michel Hervouet

Thank you. I see. I am studying these fortran file, I have a question. Advection term in the tracer transpotr equation, U*▽(T), The U is the velocity field, but if I want to change the velocity, which subroutine I can modify?

Hello,

Changing the velocity field will spoil the mass-conservation of the tracer. As a matter of fact the depth evolution and the velocities are linked by the continuity equation, and this continuity equation is used to change the conservative tracer equation into a non conservative tracer equation. Changing the velocity would require to solve a conservative tracer equation and even in this case, if the velocity field does not obey the continuity equation, the monotonicity cannot be ensured. This is what we do for the suspended sediment but in this case the deposition term copes for the problem of monotonicity. So probably you have to reconsider your problem keeping in mind these theoretical problems. I am not sure to be able to answer on the forum in the next three weeks because I'll be away, but I hope someone else can give you hints.

With best regards,

Jean-Michel Hervouet

I see. Thanks a lot.