Adjustable interrogation window for 2D PIV estimation based on local Lagrangian coherency - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Communication Dans Un Congrès Année : 2021

Adjustable interrogation window for 2D PIV estimation based on local Lagrangian coherency

Résumé

We present a novel approach to adjust shapes of the interrogation windows (IW) in Particle Image Velocimetry (PIV) measurements as a function of temporal and spatial local coherent motions. Lagrangian Coherent Structures (LCS) has been widely utilized to determine local flow boundaries. We propose using Finite-Time Lyapunov Exponent (FTLE) to quantify LCS separatrix boundaries (i.e. ridges) and adjust the interrogation window. We integrated the proposed method with a local optical flow PIV algorithm. The evaluation was performed using synthetic particle images of 2D homogeneous isotropic turbulence obtained from Direct Numerical Simulation (DNS). The results showed significant improvements in regions with complex flow behaviours, particularly shear, vortex and hyperbolic motions. We studied improvements of the velocity estimation in a real experiment of the wake flow behind a cylinder at Reynolds number equal to 3900. It was found that optical flow featured by coherency based interrogation window (coherent optical flow) reveals detailed vector field estimations in regions with complex behaviours inside the wake flow.
Fichier principal
Vignette du fichier
rahimi-khojasteh_etal_2021b_ISPIV21.pdf (13.47 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03316124 , version 1 (06-08-2021)
hal-03316124 , version 2 (24-08-2021)

Identifiants

  • HAL Id : hal-03316124 , version 2

Citer

Ali Rahimi Khojasteh, Dominique Heitz, Yin Yang. Adjustable interrogation window for 2D PIV estimation based on local Lagrangian coherency. 14th International Symposium on Particle Image Velocimetry – ISPIV 2021, Aug 2021, Chicago, United States. 7 p. ⟨hal-03316124v2⟩
88 Consultations
65 Téléchargements

Partager

Gmail Facebook X LinkedIn More