10 results on '"Gravity surface waves"'
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2. Separatrix crossing and symmetry breaking in NLSE-like systems due to forcing and damping.
- Author
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Eeltink, D., Armaroli, A., Luneau, C., Branger, H., Brunetti, M., and Kasparian, J.
- Abstract
We theoretically and experimentally examine the effect of forcing and damping on systems that can be described by the nonlinear Schrödinger equation (NLSE), by making use of the phase-space predictions of the three-wave truncation. In the latter, the spectrum is truncated to only the fundamental frequency and the upper and lower sidebands. Our experiments are performed on deep water waves, which are better described by the higher-order NLSE, the Dysthe equation. We therefore extend our analysis to this system. However, our conclusions are general for NLSE systems. By means of experimentally obtained phase-space trajectories, we demonstrate that forcing and damping cause a separatrix crossing during the evolution. When the system is damped, it is pulled outside the separatrix, which in the real space corresponds to a phase-shift of the envelope and therefore doubles the period of the Fermi–Pasta–Ulam–Tsingou recurrence cycle. When the system is forced by the wind, it is pulled inside the separatrix, lifting the phase-shift. Furthermore, we observe a growth and decay cycle for modulated plane waves that are conventionally considered stable. Finally, we give a theoretical demonstration that forcing the NLSE system can induce symmetry breaking during the evolution. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
3. Generation of Gravity Waves by Pedal-Wavemakers
- Author
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Isis Vivanco, Bruce Cartwright, A. Ledesma Araujo, Leonardo Gordillo, and Juan F. Marin
- Subjects
gravity surface waves ,wave-makers ,water-wave generation ,computational fluid dynamics ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Experimental wave generation in channels is usually achieved through wavemakers (moving paddles) acting on the surface of the water. Although practical for engineering purposes, wavemakers have issues: they perform poorly in the generation of long waves and create evanescent waves in their vicinity. In this article, we introduce a framework for wave generation through the action of an underwater multipoint mechanism: the pedal-wavemaking method. Our multipoint action makes each point of the bottom move with a prescribed pedalling-like motion. We analyse the linear response of waves in a uniform channel in terms of the wavelength of the bottom action. The framework naturally solves the problem of the performance for long waves and replaces evanescent waves by a thin boundary layer at the bottom of the channel. We also show that proper synchronisation of the orbital motion on the bottom can produce waves that mimic deep water waves. This last feature has been proved to be useful to study fluid–structure interaction in simulations based on smoothed particle hydrodynamics.
- Published
- 2021
- Full Text
- View/download PDF
4. Gravity and surface tension-driven waves
- Author
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Hedblom, Albin and Hedblom, Albin
- Abstract
In this thesis, gravity and surface tension-driven water waves are investigated by designing an experimental setup to track wave patterns using a 300 fps high speed camera. This is done to reproduce the theoretical diagram of the dispersion relation for surface waves in different teaching contexts. Surface waves are dispersive, i.e. the phase speed depends on the wavelength.Initially, the background theory for surface waves is presented and the differences between gravity and surface tension-driven waves are described. The conditions for deep and shallow water are also studied. Thereafter, a literature study is conducted to study similar experiments. Test experiments are then carried out where both direct and indirect methods of observing the waves are examined to determine which method generates the best images.The water waves in the experiment are generated by dropping a 1.6 cm marble and a 4 mm water droplet into a 35 cm diameter hexagonal tank filled with 1–10 cm deep water. The waves are recorded from above and illuminated by backlighting with a 10 W LED panel. The experimental results show that a 1.6 cm marble generates wavelengths in the 0.4–3.5 cm range. Moreover, for a 4 mm water droplet, wavelengths in the range of 0.4–2.5 cm are generated.
- Published
- 2022
5. Experiments on generation of surface waves by an underwater moving bottom.
- Author
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Jamin, Timothée, Gordillo, Leonardo, Ruiz-Chavarría, Gerardo, Berhanu, Michael, and Falcon, Eric
- Subjects
- *
SURFACE waves (Fluids) , *LABORATORIES , *DEFORMATIONS (Mechanics) , *OPEN-channel flow , *KINEMATICS , *BATHYMETRY - Abstract
We report laboratory experiments on surface waves generated in a uniform fluid layer whose bottom undergoes an upwardmotion. Simultaneousmeasurements of the free-surface deformation and the fluid velocity field are focused on the role of the bottom kinematics (i.e. its spatio-temporal features) in wave generation. We observe that the fluid layer transfers bottom motion to the free surface as a temporal highpass filter coupled with a spatial low-pass filter. Both filter effects are often neglected in tsunami warning systems, particularly in real-time forecast. Our results display good agreement with a prevailing linear theory without any parameter fitting. Based on our experimental findings, we provide a simple theoretical approach for modelling the rapid kinematics limit that is applicable even for initially non-flat bottoms: this may be a key step for more realistic varying bathymetry in tsunami scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
6. Separatrix crossing and symmetry breaking in NLSE-like systems due to forcing and damping
- Author
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Hubert Branger, Debbie Eeltink, Maura Brunetti, Jérôme Kasparian, Christopher Luneau, Andrea Armaroli, University of Geneva, Université de Genève = University of Geneva (UNIGE), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), University of Geneva [Switzerland], and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)
- Subjects
Truncation ,Plane wave ,FOS: Physical sciences ,Aerospace Engineering ,NLS ,Ocean Engineering ,Pattern Formation and Solitons (nlin.PS) ,ddc:500.2 ,Space (mathematics) ,01 natural sciences ,010305 fluids & plasmas ,symbols.namesake ,0103 physical sciences ,Phase-shift ,Symmetry breaking ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,Electrical and Electronic Engineering ,010306 general physics ,Nonlinear Schrödinger equation ,Envelope (waves) ,Physics ,Original Paper ,Forcing (recursion theory) ,Applied Mathematics ,Mechanical Engineering ,Fluid Dynamics (physics.flu-dyn) ,Separatrix crossing ,Physics - Fluid Dynamics ,Fundamental frequency ,Nonlinear Sciences - Chaotic Dynamics ,Nonlinear Sciences - Pattern Formation and Solitons ,Control and Systems Engineering ,Gravity surface waves ,Quantum electrodynamics ,symbols ,Chaotic Dynamics (nlin.CD) - Abstract
We theoretically and experimentally examine the effect of forcing and damping on systems that can be described by the nonlinear Schr\"odinger equation (NLSE), by making use of the phase-space predictions of the three-wave truncation of the spectrum. In the latter, only the fundamental frequency and the upper and lower sidebands are retained. Plane wave solutions to the NLSE exhibit modulation instability (MI) within a frequency band determined by a linear stability analysis. For modulation frequencies inside the MI-band, we experimentally demonstrate that forcing and damping cause a separatrix crossing during the evolution. Our experiments are performed on deep water waves, which are better described by the higher-order NLSE, the Dysthe equation. We therefore extend our analysis to this system. However, our conclusions are general. When the system is damped by the viscosity of the water, it is pulled outside the separatrix, which in the real space corresponds to a phase-shift of the envelope and therefore doubles the period of the Fermi-Pasta-Ulam-Tsingou recurrence cycle. When the system is forced by the wind, it is pulled inside the separatrix. Furthermore, for modulation frequencies outside the conventional MI-band, we experimentally demonstrate that contrary to the linear prediction, we do observe a growth and decay cycle of the plane-wave modulation. Finally, we give a theoretical demonstration that forcing the NLSE system can induce symmetry breaking during the evolution., Comment: 12 pages, 9 figures
- Published
- 2020
- Full Text
- View/download PDF
7. Reconciling different formulations of viscous water waves and their mass conservation
- Author
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Andrea Armaroli, Jérôme Kasparian, Maura Brunetti, and Debbie Eeltink
- Subjects
FOS: Physical sciences ,General Physics and Astronomy ,Boundary (topology) ,Angular velocity ,ddc:500.2 ,01 natural sciences ,Mass conservation ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,0103 physical sciences ,010301 acoustics ,Conservation of mass ,ddc:333.7-333.9 ,Physics ,Viscosity ,Applied Mathematics ,Fluid Dynamics (physics.flu-dyn) ,Mechanics ,Physics - Fluid Dynamics ,Vorticity ,Conservative vector field ,Computational Mathematics ,Boundary layer ,Physics - Atmospheric and Oceanic Physics ,Flow velocity ,Gravity surface waves ,Modeling and Simulation ,Free surface ,Atmospheric and Oceanic Physics (physics.ao-ph) - Abstract
The viscosity of water induces a vorticity near the free surface boundary. The resulting rotational component of the fluid velocity vector greatly complicates the water wave system. Several approaches to close this system have been proposed. Our analysis compares three common sets of model equations. The first set has a rotational kinematic boundary condition at the surface. In the second set, a gauge choice for the velocity vector is made that cancels the rotational contribution in the kinematic boundary condition, at the cost of rotational velocity in the bulk and a rotational pressure. The third set circumvents the problem by introducing two domains: the irrotational bulk and the vortical boundary layer. This comparison puts forward the link between rotational pressure on the surface and vorticity in the boundary layer, addresses the existence of nonlinear vorticity terms, and shows where approximations have been used in the models. Furthermore, we examine the conservation of mass for the three systems, and how this can be compared to the irrotational case., 32 pages, 5 figures
- Published
- 2019
8. Role of the basin boundary conditions in gravity wave turbulence
- Author
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Eric Falcon, Pablo Gutiérrez, B. Semin, Félicien Bonnefoy, Timothée Jamin, Benjamin Miquel, Luc Deike, Michael Berhanu, Matière et Systèmes Complexes (MSC), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de recherche en Hydrodynamique, Énergétique et Environnement Atmosphérique (LHEEA), École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), ANR-12-BS04-0005,TURBULON,Transfert d'énergie en turbulence d'ondes(2012), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Kolmogorov constant ,[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn] ,Capillary wave ,Wave turbulence ,FOS: Physical sciences ,Energy flux ,Physics - Classical Physics ,gravity waves ,power spectrum ,energy flux ,7. Clean energy ,01 natural sciences ,010305 fluids & plasmas ,capillary waves ,intermittency ,boundary conditions ,0103 physical sciences ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,Boundary value problem ,Gravity wave ,010306 general physics ,Physics ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph] ,laboratory experiments ,Turbulence ,Mechanical Engineering ,Fluid Dynamics (physics.flu-dyn) ,Classical Physics (physics.class-ph) ,Spectral density ,Physics - Fluid Dynamics ,Mechanics ,Nonlinear Sciences - Chaotic Dynamics ,Condensed Matter Physics ,Amplitude ,Mechanics of Materials ,[NLIN.NLIN-CD]Nonlinear Sciences [physics]/Chaotic Dynamics [nlin.CD] ,weak turbulence ,wave turbulence ,Chaotic Dynamics (nlin.CD) ,gravity surface waves - Abstract
Gravity wave turbulence is studied experimentally in a large wave basin where irregular waves are generated unidirectionally. The role of the basin boundary conditions (absorbing or reflecting) and of the forcing properties are investigated. To that purpose, an absorbing sloping beach opposite to the wavemaker can be replaced by a reflecting vertical wall. We observe that the wave field properties depend strongly on these boundary conditions. Quasi-one dimensional field of nonlinear waves propagate before to be damped by the beach whereas a more multidirectional wave field is observed with the wall. In both cases, the wave spectrum scales as a frequency-power law with an exponent that increases continuously with the forcing amplitude up to a value close to -4, which is the value predicted by the weak turbulence theory. The physical mechanisms involved are probably different according to the boundary condition used, but cannot be easily discriminated with only temporal measurements. We have also studied freely decaying gravity wave turbulence in the closed basin. No self-similar decay of the spectrum is observed, whereas its Fourier modes decay first as a time power law due to nonlinear mechanisms, and then exponentially due to linear viscous damping. We estimate the linear, nonlinear and dissipative time scales to test the time scale separation that highlights the important role of a large scale Fourier mode. By estimation of the mean energy flux from the initial decay of wave energy, the Kolmogorov-Zakharov constant is evaluated and found to be compatible with a recent theoretical value., Journal of Fluid Mechanics, Cambridge University Press (CUP), 2015, in press in JFM
- Published
- 2015
- Full Text
- View/download PDF
9. Experimental observation of four-wave resonant interactions in a wave basin
- Author
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Félicien Bonnefoy, Haudin, F., Guillaume Michel, Benoit Semin, Thomas Humbert, Sébastien Aumaître, Michael Berhanu, Eric Falcon, Laboratoire de recherche en Hydrodynamique, Énergétique et Environnement Atmosphérique (LHEEA), École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Physique et mécanique des milieux hétérogenes (UMR 7636) (PMMH), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Physique Statistique de l'ENS (LPS), Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, ANR-12-BS04-0005,TURBULON,Transfert d'énergie en turbulence d'ondes(2012), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Matière et Systèmes Complexes (MSC), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Physique et mécanique des milieux hétérogenes (PMMH), Centre National de la Recherche Scientifique (CNRS)-ESPCI ParisTech-Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
vagues océaniques ,swell ,wave spectrum ,houle ,spectre de vagues ,[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] ,[SPI]Engineering Sciences [physics] ,interactions non-linéaires ,[NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS] ,ocean waves ,ondes de gravité ,nonlinear interactions ,[NLIN.NLIN-SI]Nonlinear Sciences [physics]/Exactly Solvable and Integrable Systems [nlin.SI] ,[NLIN]Nonlinear Sciences [physics] ,gravity surface waves - Abstract
International audience; Nous étudions expérimentalement les interactions résonantes d'ondes de gravité dans un bassin de houle en profondeur infinie. Nous générons pour cela une houle bi-chromatique dont les directions des composantes forment un angle aigu et dont nous contrôlons indépendamment la cambrure et la fréquence. Ces deux ondes mères interagissent non-linéairement et donnent naissance à une onde fille dont les propriétés (taux de croissance et courbe de réponse résonante) sont pleinement caractérisées par nos essais. Tous nos résultats à faible cambrure sont en accord quantitatif avec la théorie des interactions résonantes à quatre vagues de Longuet-Higgins [1962]. Ces expériences étendent aux angles aigus les mesures faites jusqu'à présent dans la configuration de vagues perpendiculaires. Enfin, des essais à cambrure plus forte montrent l'apparition d'ondes supplémentaires qui proviennent d'interactions non-résonantes et qu'on étudie quantitativement à l'aide de l’équation de Zakharov [1968].
- Published
- 2017
- Full Text
- View/download PDF
10. Reconciling different formulations of viscous water waves and their mass conservation.
- Author
-
Eeltink, D., Armaroli, A., Brunetti, M., and Kasparian, J.
- Subjects
- *
CONSERVATION of mass , *BOUNDARY layer (Aerodynamics) , *FREE surfaces , *WATER masses , *VORTEX motion , *ROTATIONAL grazing - Abstract
The viscosity of water induces a vorticity near the free surface boundary. The resulting rotational component of the fluid velocity vector greatly complicates the water wave system. Several approaches to close this system have been proposed. Our analysis compares three common sets of model equations. The first set has a rotational kinematic boundary condition at the surface. In the second set, a gauge choice for the velocity vector is made that cancels the rotational contribution in the kinematic boundary condition, at the cost of rotational velocity in the bulk and a rotational pressure. The third set circumvents the problem by introducing two domains: the irrotational bulk and the vortical boundary layer. This comparison puts forward the link between rotational pressure on the surface and vorticity in the boundary layer, addresses the existence of nonlinear vorticity terms, and shows where approximations have been used in the models. Furthermore, we examine the conservation of mass for the three systems, and how this can be compared to the irrotational case. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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