Lagrangian diffusion properties of a free shear turbulent jet - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Fluid Mechanics Année : 2021

Lagrangian diffusion properties of a free shear turbulent jet

Résumé

A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov and large (integral) scales as well as the energy dissipation rate. Lagrangian statistical analysis is then performed on velocity components stationarised following methods inspired by Batchelor (J. Fluid Mech., vol. 3, 1957, pp. 67–80), which aim to extend stationary Lagrangian theory of turbulent diffusion by Taylor to the case of self-similar flows. The evolution of typical Lagrangian scaling parameters as a function of the developing jet is explored and results show validation of the proposed stationarisation. The universal scaling constant C0 (for the Lagrangian second-order structure function), as well as Eulerian and Lagrangian integral time scales, are discussed in this context. Constant C0 is found to converge to a constant value (of the order of C0=3) within 30 diameters downstream of the nozzle. Finally, the occurrence of finite particle size effects is investigated through consideration of acceleration-dependent quantities
Fichier principal
Vignette du fichier
Viggiano2021_JFM.pdf (2.55 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-03290080 , version 1 (19-07-2021)

Identifiants

Citer

Bianca Viggiano, Thomas Basset, Stephen Solovitz, Thomas Barois, Mathieu Gibert, et al.. Lagrangian diffusion properties of a free shear turbulent jet. Journal of Fluid Mechanics, 2021, 918, pp.A25. ⟨10.1017/jfm.2021.325⟩. ⟨hal-03290080⟩
47 Consultations
47 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More