Edge-effects in the turbulent flow over flexible aquatic vegetation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Rota, Giulio Foggi, Tressoldi, Elisa, Avallone, Francesco, Rosti, Marco Edoardo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908551284260864
author Rota, Giulio Foggi
Tressoldi, Elisa
Avallone, Francesco
Rosti, Marco Edoardo
author_facet Rota, Giulio Foggi
Tressoldi, Elisa
Avallone, Francesco
Rosti, Marco Edoardo
contents Riparian vegetation along riverbanks and seagrass along coastlines interact with water currents, significantly altering their flow. To characterise the turbulent fluid motion along the streamwise--edge of a region covered by submerged vegetation (canopy), we perform direct numerical simulations of a half--channel partially obstructed by flexible stems, vertically clamped to the bottom wall. An intense streamwise vortex forms along the canopy edge, drawing high--momentum fluid into the side of the canopy and ejecting low--momentum fluid from the canopy tip, in an upwelling close to the canopy edge. This mechanism has a profound impact on the mean flow and on the exchange of momentum between the fluid and the structure, which we thoroughly characterise. The signature of the canopy--edge vortex is also found in the dynamical response of the stems, assessed for two different values of their flexibility. Varying the flexibility of the stems, we observe how different turbulent structures over the canopy are affected, while the canopy--edge vortex does not exhibit major modifications. Our results provide a better understanding of the flow in fluvial and coastal environments, informing engineering solutions aimed at containing the water flow and protecting banks and coasts from erosion.
format Preprint
id arxiv_https___arxiv_org_abs_2507_15477
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Edge-effects in the turbulent flow over flexible aquatic vegetation
Rota, Giulio Foggi
Tressoldi, Elisa
Avallone, Francesco
Rosti, Marco Edoardo
Fluid Dynamics
Riparian vegetation along riverbanks and seagrass along coastlines interact with water currents, significantly altering their flow. To characterise the turbulent fluid motion along the streamwise--edge of a region covered by submerged vegetation (canopy), we perform direct numerical simulations of a half--channel partially obstructed by flexible stems, vertically clamped to the bottom wall. An intense streamwise vortex forms along the canopy edge, drawing high--momentum fluid into the side of the canopy and ejecting low--momentum fluid from the canopy tip, in an upwelling close to the canopy edge. This mechanism has a profound impact on the mean flow and on the exchange of momentum between the fluid and the structure, which we thoroughly characterise. The signature of the canopy--edge vortex is also found in the dynamical response of the stems, assessed for two different values of their flexibility. Varying the flexibility of the stems, we observe how different turbulent structures over the canopy are affected, while the canopy--edge vortex does not exhibit major modifications. Our results provide a better understanding of the flow in fluvial and coastal environments, informing engineering solutions aimed at containing the water flow and protecting banks and coasts from erosion.
title Edge-effects in the turbulent flow over flexible aquatic vegetation
topic Fluid Dynamics
url https://arxiv.org/abs/2507.15477