open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,there

I would like to calculate and printout the average tracer concentration on some control sections?

Which subroutine should I turn to?

Or should I make a new subroutine by myself?

Thanks in advance.

Hello,

The two subroutines computing fluxes through control sections for telemac-2D are :

flusec_telemac2d and fluxpr_telemac2d. You can also find variants into flusec_sisyphe and fluxpr_telemac2d. You can then see how the flux (array FLX) is computed. For what you want it could be an array like FLX, but with an extra multiplication by the tracer. Actually you need to decide what kind of average you want.

Regards,

JMH

You can also use post-processing functionality in Blue Kenue to compute
simple average values over a number of nodes.

1. Define a polygon that surrounds a number of nodes.
2. Select the TRACER object in the WorkSpace and then use:
"Tools->Extract TimeSeries->Constrained By..."

In the dialog that pops up choose "Average" as the type of time-series to generate and then choose your polygon with the "Where nodes are within the polygon" selector.

The resulting time-series is a simple average of the values at the selected nodes for every timestep.

See Section 1.6.5.6 in the Blue Kenue manual.

Hope this helps... Martin

Thank you, jmhervouet and Serrer.

Both of your advices are helpful.

As for the subroutine flusec_telemac2d.f, I have some questions to
discuss with you.

1)It seems that the path joining the section points pairs makes the covered elements have two verticals in the path. So how is it can be ensured the path is line not a curve?

2)In the equation,FLX(ISEC) = FLX(ISEC) + ((H1+H2)*(UN1+UN2)+H2*UN2+H1*UN1)*SUR6, what's the SUR6?Truely, I'm not sure why instaneous flux is calculated in such an equation?

3)What's use of the logical variable DEJA ?

4)What's the difference between water depth and propagation depth?

Thanks.

Hello,

Answer to 1 :

1) the cross section is approximated by a sequence of segments of the mesh. It gives the same flux in steady state and possibly a slightly different if the flow is non steady.

JMH

Hello,

I can give you some partial answers (not a specialist of control sections):
2) SUR6 = 1.D0/6.D0 as written at the beginning of the subroutine,
3) DEJA means already in French. It is a logical used in test that is only be done once, at the first time the subroutine is called (e.g. when you have to allocate arrays),
4) if you have Jean-Michel Hervouet's book, propagation depth is explained p. 93.

Regards,

Chi-Tuan