Velocity field in a single row canopy made of flexible blades for a static reconfiguration case and a monami case - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2020

Velocity field in a single row canopy made of flexible blades for a static reconfiguration case and a monami case

Résumé

Dense aquatic vegetation often plays an important role for river equilibrium, as it is a source of flow resistance promoting bed stabilization, controlling pollutant and nutrient transfer and providing a habitat for many aquatic species. These processes strongly depend on the two-way interaction between the mechanical behaviour of aquatic canopies and water flow. In this context, the present work investigates a single-row canopy made of plastic blades to model the behaviour of common macrophytes. Data from experiments in a narrow open channel and Large Eddy Simulations of the flow coupled to the unsteady blade motion via a proper robust Immersed Boundary Method are reported. The computations reproduce the blade reconfiguration quite accurately in a “static case” where the blades adopt a stationary, bent shape. Moreover, they provide detailed turbulence-resolving velocity data of the complex flow around the blades within the canopy responsible for the transfer processes named above. Secondly, a “dynamic case” with a higher flow velocity is considered, where the blades exhibit the so-called monami phenomenon. Experiments support a lock-in mechanism between blade oscillations and Kelvin-Helmholtz-like vortical structures. The simulations exhibit the same phenomenon, albeit with a larger spatial wavelength of the deformation. Instantaneous and statistical data are reported.
Fichier non déposé

Dates et versions

hal-03832568 , version 1 (27-10-2022)

Licence

Copyright (Tous droits réservés)

Identifiants

  • HAL Id : hal-03832568 , version 1

Citer

B. Löhrer, Jerome J.J.S., Sylvie Barsu, Nicolas Riviere, Delphine Doppler, et al.. Velocity field in a single row canopy made of flexible blades for a static reconfiguration case and a monami case. 10th Conference on Fluvial Hydraulics, River Flow 2020, Jul 2020, Virtual, Online, France. ⟨hal-03832568⟩
12 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More