open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,there.

In the Sisyphe mannual,there is some words explaining how to calculate Czref, please see the attached picture.I'm still confused,because to solve Czref,C is needed;while to sovle C, Czref is need.So, even if R and F are known, how can Czref and C can be solved?

Best wishes

Hong

In order to solve the concentration, the source (erosion rate E) and sink (deposition rate D) terms need to be specified.

For the erosion rate (E=Ws Cref), the equilibrium concentration Cref is determined based on empirical formulae as a function of bed shear stress.
The deposition term (D= Ws Cb) is expressed as a function of the bed concentration, which is related to the depth averaged concentration. It is an implicit term (D=Ws F C), where F is the ration between the bed concenration Cb and the depth averaged concentration C.

The documentation is rather confusing (Cb and Cref are only equal when equilibrium is reached) and we will try to be more clear in the new documentation (v6.2).

Hope this helps, Cath