open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all,

Before getting stuck in to making any modifications I just want to make sure I fully understand the existing source code for the calculation of the implicit source terms in the tracer equation.

Looking at lines 177 - 190 in difsou.f:

177 ! IMPLICIT SOURCE TERMS (DEPENDING ON THE LAW CHOSEN)
178 !
179 DO ITRAC=1,NTRA
180 IF(LOITRAC(ITRAC).EQ.0) THEN
181 YASMI(ITRAC)=.FALSE.
182 ELSEIF(LOITRAC(ITRAC).EQ.1) THEN
183 YASMI(ITRAC)=.TRUE.
184 CALL OS('X=CY ',X=TIMP%ADR(ITRAC)%P,Y=HPROP,
185 & C=-2.3D0/COEF1TRAC(ITRAC)/3600.D0)
186 ELSE
187 IF(LNG.EQ.1) WRITE(LU,*) 'DIFSOU : LOI NON PROGRAMMEE'
188 IF(LNG.EQ.2) WRITE(LU,*) 'DIFSOU : LAW NOT IMPLEMENTED'
189 ENDIF
190 ENDDO

As I understand the variable C (line 185) is the decay constant (often written as K in most literature) which is based on the T90 value, COEF1TRAC(ITRAC).

Does variable X (line 184) refer to the implicit source term (SMI) in the tracer equation; see cvdftr.f. If not which variable does it refer to?

I have had a look through the user manuals and searched the forum but can't find the answer hence this post, sorry if it has already been asked and answered.

Many thanks in advance
Jon

Hello,

You are correct, no problem. Actually the implicit term SMI is used in the equation with a division by the depth, which is generally convenient, but not in this case, this is why there is a multiplication by the depth at line 184.

With best regards,

Jean-Michel Hervouet

Hi,

Thank you. I thought that might be the case with the multiplication by HPROP on line 184 but it's good to have confirmation.

Thanks again
Jon