open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi!!

I'm interested in a tracer transport simulation with a first-order decay coefficient variable in space in different zones. I've already implemented the procedure that accounts for different friction losses in space and I want to know if is possible to do the same for the decay coefficient.

In the user's manual I read that I must change DIFSOU subroutine but I did not understand how to do this. Can anyone help me or give me some advices??

Thanks!

Tom

Hi Tom
In subroutine DIFSOU you had an example of tracer decay programming.
I'll advise you to try to implement a constant decay with the example given in the subroutine and when it works well, you wil ladd the varaibility in space (the programmation should be similar to what you do for the friction losses).

Regards

Hello,

You need to take subroutine difsou (library telemac-2D) in the user Fortran file. If you don't have any you will have to add:

FORTRAN FILE : nameoffile

in your parameter file

Then you can change this difsou.f for your own needs, inside there is an example of decay which is applied only into a rectangle in the mesh.

With best regards,

Jean-Michel Hervouet

As you suggested, I run TELEMAC with the example you show in the subroutine difsou.f. I have only a question that concerns the units of the decay coefficient: does the value, you used in the example (-0.0001*T(N+1)), have the units [1/s]? Dimensionally it seems correct to me, but I prefer to have a confirmation.

In the case I use a value of decay coefficient expressed in [m/s] should I discard to multiply for HPROP?

Thanks!

Hello,

Yes, this is correct if you consider that the tracer has no dimension (kg of sediment per kg of water for example). Then the terms in the tracer equation are of unit [1/s].

With best regards,

Jean-Michel Hervouet