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Main Authors: Pimienta, Juan, Aider, Jean-Luc
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2407.03057
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author Pimienta, Juan
Aider, Jean-Luc
author_facet Pimienta, Juan
Aider, Jean-Luc
contents Particle Image Velocimetry (PIV) is the most commonly used optical technique for measuring 2D velocity fields. However, improving the spatial resolution of instantaneous velocity fields and having access to the velocity field in real time remains a challenge. Optical Flow veolcimetry makes it possible to meet these challenges. In this study, we show that it is possible to access dense velocity fields (1 vector per pixel) in real-time using an appropriate seeding concentration adapted to optical flow algorithms and no longer to cross-correlation PIV algorithms. The influence of concentration on the quality of velocity fields is demonstrated using synthetic images generated for a Rankine vortex. We thus demonstrate that it is possible to precisely measure small vortices using optical flow provided that the seeding is suitable. The notion of "Active Pixels" is also introduced in order to define a seeding optimization criterion adapted to experimental measurements. This criterion is finally successfully applied to the flow downstream of a cylinder leading to a spatial resolution down to one vector per pixel.
format Preprint
id arxiv_https___arxiv_org_abs_2407_03057
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Towards High Resolution Real-Time Optical Flow Particle Image Velocimetry
Pimienta, Juan
Aider, Jean-Luc
Fluid Dynamics
Particle Image Velocimetry (PIV) is the most commonly used optical technique for measuring 2D velocity fields. However, improving the spatial resolution of instantaneous velocity fields and having access to the velocity field in real time remains a challenge. Optical Flow veolcimetry makes it possible to meet these challenges. In this study, we show that it is possible to access dense velocity fields (1 vector per pixel) in real-time using an appropriate seeding concentration adapted to optical flow algorithms and no longer to cross-correlation PIV algorithms. The influence of concentration on the quality of velocity fields is demonstrated using synthetic images generated for a Rankine vortex. We thus demonstrate that it is possible to precisely measure small vortices using optical flow provided that the seeding is suitable. The notion of "Active Pixels" is also introduced in order to define a seeding optimization criterion adapted to experimental measurements. This criterion is finally successfully applied to the flow downstream of a cylinder leading to a spatial resolution down to one vector per pixel.
title Towards High Resolution Real-Time Optical Flow Particle Image Velocimetry
topic Fluid Dynamics
url https://arxiv.org/abs/2407.03057