An experimental study on the settling velocity of inertial particles in different homogeneous isotropic turbulent flows - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Fluid Mechanics Année : 2023

An experimental study on the settling velocity of inertial particles in different homogeneous isotropic turbulent flows

Résumé

We propose an experimental study on the gravitational settling velocity of dense, sub-Kolmogorov inertial particles under different background turbulent flows. We report phase Doppler particle analyser measurements in a low-speed wind tunnel uniformly seeded with micrometre scale water droplets. Turbulence is generated with three different grids (two consisting of different active-grid protocols while the third is a regular static grid), allowing us to cover a very wide range of turbulence conditions in terms of Taylor-scale-based Reynolds numbers (Re λ ∈ [30-520]), Rouse numbers (Ro ∈ [0-5]) and volume fractions (φ v ∈ [0.5 × 10 −5-2.0 × 10 −5 ]). We find, in agreement with previous works, that enhancement of the settling velocity occurs at low Rouse number, while hindering of the settling occurs at higher Rouse number for decreasing turbulence energy levels. The wide range of flow parameters explored allowed us to observe that enhancement decreases significantly with the Taylor-Reynolds number and is significantly affected by the volume fraction φ v. We also studied the effect of large-scale forcing on settling velocity modification. The possibility of changing the inflow conditions by using different grids allowed us to test cases with fixed Re λ and turbulent intensity but with different integral length scale. Finally, we assess the existence of secondary flows in the wind tunnel and their role on particle settling. This is achieved by characterising the settling velocity at two different positions, the centreline and close to the wall, with the same streamwise coordinate.
Fichier principal
Vignette du fichier
Main document.pdf (3.84 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-04199631 , version 1 (11-09-2023)

Identifiants

Citer

Amélie Ferran, Nathanaël Machicoane, Alberto Aliseda, Martín Obligado. An experimental study on the settling velocity of inertial particles in different homogeneous isotropic turbulent flows. Journal of Fluid Mechanics, 2023, 970, pp.A23. ⟨10.1017/jfm.2023.579⟩. ⟨hal-04199631⟩

Collections

UGA CNRS OSUG LEGI
18 Consultations
7 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More