open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi~

I use the Telemac for simulating the concentration of the E.coli in the canal. But I don't know how to add a decay rate in source_trac.f. For example: 20% in one hour. How can I modify the source_trac.f.

I konw it's a very simple question but I've just start to use it. Thank you!

Regards!

Shuo

Hi,

You can have a look to the "tracer decay" or "tracer_decrease" examples in telemac2d example folder.
WATER QUALITY PROCESS must be set to 17 in your telemac steering file and COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION is the time constant (in hours) for the exponential decrease of tracer concentration, in your waqtel steering file. You can modify the degradation law in "source_waq.F", around line 300 (waqtel sources).

Hope it helps.

Regards,
Laurent

Think you very much.

But I use the model of Telemac 3D and can I use also the keyword: COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION?

The tracer decay feature is common for 2D and 3D models.
Since v8 releases of the code, the feature has been moved in waqtel, so it's a keyword to include to the waqtel steering file.

Regards,
Laurent

thank you.

But in ma waq_steer.cas,I just have 5 WATER QUALITY PROCESS. You can look it in the attachments.
Can I just set it to 17 and add the keyword?

Regards.
Shuo

Your steering file is a generic one, set for thermic process study.
Please, have a look to the examples I mentioned.

Regards,
Laurent

I'm sorry to bother you again, I have tried lots of time, but it didn't work. I think my visions is a little old(V2P2)
In my case, the tracer 2 is the E.coli, so I edit the codes below in the source_trac.f.
INTEGER IPOIN3, IPOIN2, IPLAN
DOUBLE PRECISION DECAYDAY,DECAYRATE
DO ITRAC=1,NTRAC
S0TA%ADR(ITRAC)%P%TYPR='0'
S1TA%ADR(ITRAC)%P%TYPR='0'
ENDDO
DECAYDAY = D0
DECAYRATE = 0.9D0

UNIFORM DECAY RATE FOR TRACER NUMBER 2 (%ADR(2)) -
IF(NTRAC.GE.2) THEN

S0TA%ADR(2)%P%TYPR='Q'
S1TA%ADR(2)%P%TYPR='Q'
DO IPOIN3 = 1,NPOIN3
S0TA%ADR(2)%P%R(IPOIN3) = TA%ADR(2)%P%R(IPOIN3) *
& DLOG( 1.D0-DECAYRATE ) / ( DECAYDAY*24*3600.D0 ) / 2.D0
S1TA%ADR(2)%P%R(IPOIN3) =
& - DLOG( 1.D0-DECAYRATE ) / ( DECAYDAY*24*3600.D0 ) / 2.D0
ENDDO
!
ENDIF

Is that all right? And how can I use it in the t3d_heat_exchange.cas.Because I have already used t3d_heat_exchange.f.

Thank you very much for your help.