open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi all!

I have a few questions regarding sediment transport computations.
I read the manual as well as some posts here on the forum, but I thought it would be clearer to ask my questions directly here.

Is it possible to set a time varying bed load (or concentration) rate at a boundary?
I have read that a fixed bed load rate can be set in the conlit subroutine, but what about a time-varying condition?

The purpose is to model deposition of flushed materials downstream of a dambreak. I thought of processing as follows:
1. computing the flushing (bed load) rate out from the reservoir with the liquid dambreak hydrograph as DS BC
2. Introducing the previously computed bed load hydrograph as US BC in a second model for the DS reach.

Any other suggestions would be of course greatly appreciated!

Thank you in advance for your help,
PL

Hi PL,
Yes, it is possible in the new version v6.2.
For the new conlit.f you have also the time as input variable, so you can program your time-depending sediment input.
For suspended load, concentrations can be fixed or imposed by reading an input concentration file (for time-varying concentrations).

All the best,

Pablo

Thank you Pablo.

I have read the new dico file for 6.2, and i discovered that the keyword LIQUID BOUNDARIES FILE has been added (as well as PRESCRIBED SOLID DISCHARGES for constant values). Which variables can be defined in this file (I don't really understand the mention to the SIS_FILES(SISLIQ)%LU channel)? It would be great if it could be sediment transport rates
Is there a validation case available as an example ?

Thank you in advance,
PL

Hi PL,
below you can found a sample of the "LIQUID BOUNDARIES FILE"

# Temps (s) Conc_inflow Discharge (m3/s) WSE(m)

T Q(1) CG(1) SL(2)

0 100.0 0.1 200.0

1800 100.0 0.1 205.0

5400 200.0 0.2 205.0
... ... ... ...

For the prescribed solid discharges, you can take a look to the example 002_canal_solid_discharge_inflow in the folder validation.

all the best,

Pablo

Hi,

Thank you for that, but to what does correspond the CG variable in your liquid file example ? I guess it is solid concentration ?
I looked in the manuals but found no track of this variable.
Furthermore, can solid discharges be defined via a liquid (?) boundaries file ? Or is it only possible via the keyword used in the steering file (constant values) or via conlit.f (in such a case, does it exist a programming example ?)?

Thank you in advance,
PL

Hi,
* for suspended load you can impose time-varying sediment concentrations via LIQUID BOUNDARIES FILE.
* for bedload, you can specify a fixed value via the keyword PRESCRIBED SOLID DISCHARGE, or within the boundary conditions file (cli file). Please take a look to the attached doc (that is part of "sisyphe v6.2 news" document, that will be available soon). For time-varying solid discharge, you must use the subroutine conlit.f (as done before).

I hope this helps,

Pablo

Thank you for this!