open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,
Considering the tracers TEMPERATURE,SALINITY and TRACER3(user defined), How should one make use of the available options?
BETA EXPANSION COEFFICIENT FOR TRACERS
STANDARD VALUES FOR TRACERS

If one wishes to provide (BETA EXPANSION COEFFICIENT) for temperature as 0.05, for salinity as 0.06 and for TRACER3 as 0.2, which among them is given first priority while writing in the steering file?
BETA EXPANSION COEFFICIENT FOR TRACERS:0.05;0.06;0.2 (temp;sal;trac)

or

BETA EXPANSION COEFFICIENT FOR TRACERS:0.06;0.05;0.2 (sal;temp;trac)

Thanks in advance
SATHYA

Hello,

Beware with the definition of the BETA EXPANSION COEFFICIENT FOR TRACERS, they sometimes are negative, temperature and salinity coefficients should not be of the same sign.

Then you have a keyword : NAMES OF TRACERS, these names are given in 32 characters, with 16 for the name and 16 for the unit. The order of names gives the order of tracers, then Telemac recognises the name TEMPERATURE and looks for the string SALINIT to know where is the salinity, so the ranks of salinity and temperature given by the user (called IND_S and IND_T in the program) are deduced from the names.

With best regards,

Jean-Michel Hervouet

Hello,
While using the option COEFFICIENT FOR HORIZONTAL DIFFUSION OF TRACERS, is it possible to provide different values for different tracers as follows?

NUMBER OF TRACERS : 4
COEFFICIENT FOR HORIZONTAL DIFFUSION OF TRACERS : 0.001:0.05;1.0E-6;1.0E-3

Thanks in advance
SATHYA

Hello,

No, this is not done yet. It is not difficult to do but nobody asked for it, probably because all these coefficients are very small and hidden by the turbulence. Anyway I'll do it for the next release. In the while, depending on your turbulence model (probably constant), you can act in subroutine viscos.f where you will see that every tracer gets a horizontal diffusion coefficient equal to DNUTAH, which is the keyword HORIZONTAL DIFFUSION COEFFICIENT FOR TRACERS. Instead of DNUTAH you can put your values depending on tracer number ITRAC.

With best regards,

Jean-Michel Hervouet