Papers by Philippe Petitjeans
Vortices
Cambridge University Press eBooks, Jan 12, 2004
Time reversal of linear and nonlinear water waves
arXiv (Cornell University), Jan 12, 2022
Fluids, Apr 23, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
HAL (Le Centre pour la Communication Scientifique Directe), Apr 23, 2012
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Aug 29, 2022
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Apr 23, 2012
HAL (Le Centre pour la Communication Scientifique Directe), Apr 23, 2012
arXiv (Cornell University), Feb 12, 2022
Playing a role in the locomotion of some animals such as the water strider, the formation and dyn... more Playing a role in the locomotion of some animals such as the water strider, the formation and dynamics of a semi vortex ring connected to a free surface are experimentally investigated. This semi vortex ring is generated by the circular motion of a flat circular disk in water. Digital Particle Image Velocimetry provides velocity fields and vortex properties. We show how in a broad range of Reynolds numbers, the properties of the semi vortex rings are related to the disk characteristics. In particular, our results highlight a formation process more complex than for a complete vortex ring produced by a piston stroke. In addition to the classical rolling up at the rear of the disk, a shedding phenomenon occurs on the leading edge, producing secondary vortices. The Strouhal number related to this shedding process reveals that it comes from the free-shear instability of the boundary layer identified in the near wake of a cylinder by Bloor. Finally we show that the disk thickness affects the final properties of the semi vortex rings through emission frequency of secondary vortices.
Transformation Wave Physics: Electromagnetics, Elastodynamics and Thermodynamics
International audienceSpace–time transformations as a design tool for a new class of composite ma... more International audienceSpace–time transformations as a design tool for a new class of composite materials (metamaterials) have proved successful recently. The concept is based on the fact that metamaterials can mimic a transformed but empty space. Light rays follow trajectories according to Fermat’s principle in this transformed electromagnetic, acoustic, or elastic space instead of laboratory space. This allows one to manipulate wave behaviors with various exotic characteristics such as (but not limited to) invisibility cloaks.This book is a collection of works by leading international experts in the fields of electromagnetics, plasmonics, elastodynamics, and diffusion waves. The experimental and theoretical contributions will revolutionize ways to control the propagation of sound, light, and other waves in macroscopic and microscopic scales. The potential applications range from underwater camouflaging and electromagnetic invisibility to enhanced biosensors and protection from harmful physical waves (e.g., tsunamis and earthquakes). This is the first book that deals with transformation physics for all kinds of waves in one volume, covering the newest results from emerging topical subjects such as transformational plasmonics and thermodynamics
Time domain modelling of a Helmholtz resonator analogue for water waves
Journal of Fluid Mechanics, 2021
Abstract In the context of water waves, we consider a resonator with deep subwavelength resonance... more Abstract In the context of water waves, we consider a resonator with deep subwavelength resonance, analogue to the Helmholtz resonator in acoustics. In the shallow water regime, using asymptotic analysis, a one-dimensional model is derived in which the effect of the resonator is reduced to effective transmission conditions. These conditions clearly highlight two contributions. The first is associated with the dock on its own and it is responsible for a jump of the potential at the free surface. The second is due to the resonant cavity and it is responsible for a jump in the horizontal velocity. It involves as well the uniform amplitude within the resonant cavity with a transient dynamics explicitly given by the equation of a damped oscillator forced by the incident waves. The one-dimensional model is validated in the harmonic regime by comparison to direct two-dimensional numerics. It is shown to reproduce accurately the scattering coefficients and the amplitude within the resonator; interestingly, this remains broadly true for finite water depths. We further inspect the spatio-temporal behaviour of different types of wave packets interacting with the resonating and radiating cavity.
HAL (Le Centre pour la Communication Scientifique Directe), 2022
Physical Review E, Nov 19, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Physics Procedia, 2015
Nonlinear water waves have been studied for decades. However, numeric models have always been val... more Nonlinear water waves have been studied for decades. However, numeric models have always been validated with punctual measurements. In this study we measure the surface deformation of water waves with the Fourier Transform Profilometry (FTP) technique, obtaining a complete space-time resolved field. This permits to separate free and bound waves in the shallow water region, revealing the near resonant interaction between those components. When we change the absorbing beach by a reflecting wall at the end of the channel, we observe an interesting resonance for fixed frequencies. At the resonant frequencies, the system shows a chaotic behavior.
Measurement of asymmetrical water waves wake due to an anisotropic bathymetry
Bulletin of the American Physical Society, Mar 2, 2020
Study of the Turbulent Energy Spectrum Build Up in an Experimental Vortex Burst
HAL (Le Centre pour la Communication Scientifique Directe), Aug 15, 2004
Experimental study of 1D Su-Schrieffer-Heeger edge modes in a water-wave channel
Bulletin of the American Physical Society, Mar 4, 2020
Dynamics of miscible displacements in round tubes
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Dec 31, 1995
A combined experimental and numerical investigation of miscible two-phase flow in a capillary tub... more A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.
HAL (Le Centre pour la Communication Scientifique Directe), 2005
We report experimental results on the evolution of a laminar liquid jet injected with negatively ... more We report experimental results on the evolution of a laminar liquid jet injected with negatively buoyant condition in a miscible surrounding liquid. Since molecular diffusion is negligible, the only significant miscible effect is the absence of any surface tension. After an initial intrusion phase, the jet reaches a steady-state characterized by a constant penetration depth. A simple theoretical model is derived which successfully predicts the transient phase as well as the subsequent steady state in terms of stationary penetration depth and jet's profile. All the experimental points collapse on a master curve involving two dimensionless numbers: the densimetric Froude number Fr and S, a number comparing viscous friction to buoyancy. Finally, this curve obtained for laminar flows is compared to classical results on turbulent fountains.
Instabilités à "l'interface" entre deux fluides miscibles. Émergence d'une tension de surface effective
Journal de chimie physique, Jun 1, 1999
Instabilities can develop at the "interface" between tw... more Instabilities can develop at the "interface" between two miscibles fluids which exihibit patterns very similar to those observed between immiscible fluids. For example, a layer of colored glycerine hanged-up below a glass plate and placed into a water tank, gives rise to organized patterns. Also, a thin layer of glycerine falling into water is unstable and gives falling columns with
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Papers by Philippe Petitjeans