open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all,

I was hoping to get some clarification on determining volume of bedload at a given cross section through a model.

In the VARIABLES FOR GRAPHIC PRINTOUTS keyword for SISPHYE, there is a variable 'M="bed-load discharge (m2/s)"' as indicated in the .dico definition. The unit stated indicates m2/s, but using this print out:

- attempting to use the average nodal values in the SOLID DISCH results mesh * outflow boundary width should give solid discharge in m3/s, but the value is inconsistent with the "BOUNDARY x BEDLOAD FLUX = xxxxxxx ( M3/S >0 = ENTERING )" output in the sortie file

- assuming that the unit for M is m3/s instead, sum of the nodal value at said boundary still does not equate the value stated in the sortie file


I was hoping to get some clarification on the units used for both the M (SOLID DISCH) variable and the BEDLOAD FLUX output in the sortie, and/or the correct way to calculate the actual solid discharge through a given cross section (or boundary) in a model.

Thanks all in advance for your time :)

-Wayne

Dear Wayne,
The variable printed with the flag "M" in the VARIABLES FOR GRAPHIC PRINTOUTS keyword for sisyphe gives you the unit bedload discharge, expressed by volume (m2/s). The unit bedload discharge is the flux of sediment per unit width per unit time moving in the bed layer.

The output information that the code print for a chosen listing printout period is the value of the bedload discharge/(1-porosity) (at each boundary and total), expressed in m3/s. The bedload discharge is the integral over the boundary (or channel width) of the unit bedload discharge. The subroutine that prepares all this information is bilan_sisyphe.f, located in the sisyphe' source directory.

I hope it helps,

all the best,

Pablo