Abstract :
[en] Shallow reservoirs are widely used in hydraulic engineering, whether for temporary
water storage, or as settling basins. Many of these reservoirs have a relatively simple geometric
configuration (i.e., rectangular), but exhibit complex flow phenomena (i.e., eddies, recirculation
zones, attached or oscillating jets) and even instable flow patterns. This impacts the sediment
transport and sedimentation (e.g., deposition rate, location), and thus the operational efficiency of
reservoirs. The objective of this thesis is to enhance our understanding of the physical hydro-
sedimentary processes in shallow reservoirs through experimentation and numerical modeling.
Design of the laboratory setup was inspired by real basins and was carried out based on
dimensional analysis and preliminary numerical simulations using the open source two-depth
averaged model TELEMAC-2D (2D) and three-dimensional (3D) model TELEMAC-3D. A series
of forty-two (42) experiments with clear water and fifteen (15) experiments with inlet sediment
injection were conducted. Velocity fields were measured using the LSPIV (Large Scale Particle
Image Velocimetry) technique as well as intrusive probes such as the ADV (Acoustic Doppler
Velocimeter) and ADVP (Acoustic Doppler Velocimeter Profiler). This later technique allowed
precise and advanced evaluation of average velocities and flow turbulent characteristics.
Sedimentation within the reservoir was mapped using an echosounder, while the time-evolution
of deposit pattern was analyzed through image processing. These experiments helped to clarify
the impact of inlet boundary conditions (open channel vs pressurized jet), geometric (short vs long
reservoirs), hydraulic and sediment conditions. Using the experimental data, the software
code_saturne was used to assess the capability of turbulence models, both low and high Reynolds
numbers, to observed replicate stable and unstable flow patterns. Finally, a real-world case was
stimulated using TELEMAC-2D coupled with its sediment transport module GAIA.
