How to make a 2D numerical morphodynamic model?
Résumé
The Public Health - Environmental Quality Department of the Grand
Poitiers municipality ensures that the territory's biodiversity issues as well as
the implementation of GEMAPI (Gestion des Milieux Aquatiques et Prévention
des Inondations). Owner of transverse structures, Grand Poitiers conducts a
preliminary re
ection on the restoration of Ecological Continuity, in partnership
with the PPRIME Institute of the University of Poitiers and the French
Biodiversity Agency. To define a policy for the development of transverse
structures, it is necessary to be able to evaluate the effects of this development
on the sediment transport at the scale of rivers. Numerical hydromorphodynamic
models, such as HEC-RAS, perform a 2D modeling based on
the vertical integration of equations governing the physical mechanisms. This
strategy reduces the cost of CPU time compared to 3D numerical models.
However, the study on large time and space scales remains expensive in terms
of CPU time. To correct this default, one solution is to use HydroSedFoam.
By solving the Saint Venant Exner equations, HydroSedFoam allows to study
the impact of transverse structures on the hydro-morphodynamic behavior
of rivers. The main advantages of HydroSedFoam are to be developed under
OPENFOAM (thus open sources) and to be parallelized to run on supercomputers
such as the machines of the mesocenter of the University of Poitiers
and the national center of calculations GENCI. In 2021, a first internship has
allowed to implement the use of HydroSedFoam. A performance study must
now be carried out to show the performance of HydroSedFoam compared
to other 2D numerical hydro-morphodynamic models, such as HEC-RAS, to
solve the Saint Venant Exner equations on large time and space scales. It is
the objective of this scientific work.