open TELEMAC-MASCARET The mathematically superior suite of solvers

Yes, I can understand it. But option 1: dT/dt+u.grad(T)-div(vt*grad(T))=0
I cannot understand this. Where is the h？

Hello,

In the term 1/h * div(h*vt*grad(T)) the h outside the divergence term is simplified with the h inside the divergence term. It is wrong mathematically but this is the approximation...

JMH

You mean if option=1, 1/h * div(h*vt*grad(T))=div(vt*grad(T)) in approximation?

Yes, simplifying across the divergence, which neglects a term which is proportional to div(h).

Oh, I see. I cannot understand before when I am reading the mannual. Thank you very much.
So if the source term SM in tracer transport equation is u*T/h, the TEXP in difsou.f is TEXP=u*T/h, the h is indispensable， it is right？

Yes, it is dT/dt+..... = TEXP

JMH

Thank you very much!