Étude par vélocimétrie volumique d'un jet dans un écoulement transverse à faibles ratios de vitesses.

Abstract : This thesis is dedicated to the experimental study of a Jet In Cross-Flow (JICF). The flow is monophasic and isothermal. The velocity ratio (VR) between jet and cross-flow velocities is low (0.15 < VR < 3), and the jet exit is flush at the wall. Diverse jet geometries are considered: circular, elliptic, rectangular, and winglet. This study was realized in hydraulic channel using a new optical velocimetry method (V3V) which provides accurate measurements of the 3 components of the instantaneous velocity field. The whole experimental process was optimized. The physics of the JICF is investigated by means of the average and instantaneous fields, through their statistics and using a spatial follow-up of the main vortical structures. The influence of the VR on the flow topology is analyzed, and highlights the existence of a blowing transition at very low velocity ratio. We analyze in detail the trajectories swirling intensities of the main vertical structures, and a new scaling of trajectories, taking into account the boundary layer, is proposed. These results facilitate the interpretation of the elliptic and rectangular, straight and skewed JICF physics. The study of the half-winglet geometry allowed for an analysis of the winglet configuration, and a better comprehension of their effects on the boundary layer. All these results allows for a better understanding of the jet in cross-flow physic at low velocity ratios. They should also be useful for flow control experiments, by providing quantitative criteria to choose the relevant physical and geometrical parameters for vortex generators design.
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Contributor : Tristan Cambonie <>
Submitted on : Thursday, February 28, 2013 - 2:47:43 PM
Last modification on : Friday, March 22, 2019 - 1:30:53 AM
Long-term archiving on : Wednesday, May 29, 2013 - 5:55:16 AM

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  • HAL Id : pastel-00795587, version 1

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Tristan Cambonie. Étude par vélocimétrie volumique d'un jet dans un écoulement transverse à faibles ratios de vitesses.. Mécanique des fluides [physics.class-ph]. Université Pierre et Marie Curie - Paris VI, 2012. Français. ⟨pastel-00795587⟩

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