Cyprien Morize

• University of Paris-Sud

In the present study, we investigated the generation phase of laboratory-scale water waves induced by the impulsive motion of a rigid piston, whose maximum velocity $U$ and total stroke $L$ are independently varied, as well as the initial liquid depth $h$. By doing so, the influence of two dimensionless numbers is studied: the Froude number $\mathr...

The presence of interparticle cohesion can drastically change the behavior of granular materials. For instance, powders are challenging to handle, and one can make a sandcastle using wet grains. In this study, we report experimental results for columns of model cohesive grains collapsing under their own weight in air and spreading on a rough horizo...

Les tsunamis générés par des glissements de terrains ou la chute de pans de montagnes dans les océans, lacs ou fleuves, peuvent être particulièrement destructeurs et meurtriers pour les côtes avoisinantes. Ces évènements ont été dernièrement reproduits en laboratoire, dans une configuration modèle semblable à celle d’un château de sable s’écroulant...

In this article, we investigate experimentally and numerically the time evolution of vortex rings generated by the translation of a rigid disk in a fluid initially at rest and submitted to an acceleration followed by a deceleration. The diameter of the disk and its motion in terms of stroke length and travel time are varied as control parameters. T...

In this article, we investigate experimentally and numerically the time evolution of vortex rings generated by the translation of a rigid disk in a fluid initially at rest and submitted to an acceleration followed by a deceleration. The size of the disk and its motion in terms of stroke length and travel time are varied as control parameters. The s...

In this article, we present a predictive model for the amplitude of impulse waves generated by the collapse of a granular column into a water layer. The model, which combines the spreading dynamics of the grains and the wave hydrodynamics in shallow water, is successfully compared to a large dataset of laboratory experiments, and captures the influ...

In this article, we present a predictive model for the amplitude of impulse waves generated by the collapse of a granular column into a water layer. The model, which combines the spreading dynamics of the grains and the wave hydrodynamics in shallow water, is successfully compared to a large dataset of laboratory experiments, and captures the influ...

Tsunamis are among the most destructive natural disasters for human coastal settlements. While events generated by earthquakes are well known, several past or potential occurrences of high amplitude waves arising from large-scale landslides have also been reported in the last decades. The famous 1958 Lituya Bay tsunami, featuring the highest record...

Gravity-driven collapses involving large amounts of dense granular material, such as landslides, avalanches, or rock falls, in a geophysical context, represent significant natural hazards. Understanding their complex dynamics is hence a key concern for risk assessment. In the present work, we report experiments on the collapse of quasi-two-dimensio...

Gravity-driven collapses involving large amounts of dense granular material, such as landslides, avalanches, or rockfalls, in a geophysical context, represent significant natural hazards. Understanding their complex dynamics is hence a key concern for risk assessment. In the present work, we report experiments on the collapse of quasi-two-dimension...

Modeling of tsunami waves generated by subaerial landslides is important to provide accurate hazard and risk assessments in coastal areas. We perform small-scale laboratory experiments where a tsunami-like wave is generated by the gravity-driven collapse of a subaerial granular column into water. We show that the maximal amplitude reached near-shor...

Tsunami waves induced by landslides are a threat to human activities and safety along coastal areas. In this paper, we characterize experimentally the waves generated by the gravity-driven collapse of a dry granular column into water. Three nonlinear wave regimes are identified depending on the Froude number Fr based on the ratio of the velocity of...

Tsunami waves induced by landslides are a threat to human activities and safety along coastal areas. In this paper, we characterize experimentally the waves generated by the gravity-driven collapse of a dry granular column into water. Three nonlinear wave regimes are identified depending on the Froude number $\mathrm{Fr}_f$ based on the ratio of th...

The generation of a tsunami wave by an aerial landslide is investigated through model laboratory experiments. We examine the collapse of an initially dry column of grains into a shallow water layer and the subsequent generation of waves. The experiments show that the collective entry of the granular material into water governs the wave generation p...

Tsunami-like waves can arise from large-scale geological events such as the collapse of a mountain flank or a volcano into a lake or an ocean. We here mimic this situation at the laboratory scale. The landslide is modeled by the sudden release of a rectangular granular column, which impacts a still water layer and generates a wave. Through experime...

The generation of a tsunami wave by an aerial landslide is investigated through model laboratory experiments. We examine the collapse of an initially dry column of grains into a shallow water layer and the subsequent generation of waves. The experiments show that the collective entry of the granular material into water governs the wave generation p...

Under suitable conditions, an immersed granular bed can be destabilized by local thermal forcing and the induced buoyant force. The destabilization is evident from the triggering and establishment of a dense fluid-like granular plume. Varying the initial granular layer average height $h$ , a time series of the free layer surface is extracted, allow...

We investigate experimentally the local erosion of a granular bed near a fixed vertical cylinder that emerges from the bed. The onset of erosion arising at the base of the cylinder and usually ascribed to the wrapping horseshoe vortex is determined and rationalized by a flow contraction effect. We report a new erosion pattern visible downstream of...

We investigate experimentally the local erosion of a granular bed near a fixed vertical cylinder that emerges from the bed. The onset of erosion arising at the base of the cylinder and usually ascribed to the wrapping horseshoe vortex is determined and rationalized by a flow contraction effect. We report a new erosion pattern visible downstream of...

The resuspension and dispersion of particles occur in industrial fluid dynamic processes as well as environmental and geophysical situations. In this paper, we experimentally investigate the ability to fluidize a granular bed with a vertical gradient of temperature. Using laboratory experiments with a localized heat source, we observe a large entra...

The resuspension and dispersion of particles occur in industrial fluid dynamic processes as well as environmental and geophysical situations. In this paper, we experimentally investigate the ability to fluidize a granular bed with a vertical gradient of temperature. Using laboratory experiments with a localized heat source, we observe a large entra...

We report on two different patterns that can be observed at the bed surface close to a vertical cylinder when submitted to a strong enough steady water flow. The classical scour pattern observed at the cylinder foot and due to the “horseshoe” vortex around occurs at a critical velocity Uc1 below the critical velocity Uc0 for erosion without any cyl...

We consider experimentally the wave generation by the collapse of a dry granular column into water. Our results show that for a given aspect ratio of the initial granular column, the amplitude of the generated wave depends on the column mass and for a given mass of the granular column, two distinct regimes are observed depending on the aspect ratio...

We study both experimentally and numerically the steady zonal flow generated by longitudinal librations of a spherical rotating container. This study follows the recent weakly nonlinear analysis of Busse (2010), developed in the limit of small libration frequency - rotation rate ratio, and large libration frequency - spin-up time product. Using PIV...

Au-delà du phénomène bien connu de flux et de reflux de la mer sur nos rivages, les marées sont également responsables de phénomènes très variés. Nous présenterons une première vérification expérimentale que l’auto-intéraction d’un mode inertiel non-linéaire avec lui-même peut conduire à un écoulement axisymétrique intense dans une sphère en rotati...

Significant axisymmetric stationary flows can be generated by the action of an harmonic forcing on a rotating fluid in a sphere. Such a mechanism could be of fundamental importance in natural systems, for instance in planetary cores subject to libration, precession or tides. Using a weakly non-linear analysis, we first show that the mechanism of zo...

We describe a new phenomenon of zonal wind generation by tidal forcing. Following a recent theoretical and numerical analysis [A. Tilgner, Phys. Rev. Lett. 99, 194501 (2007)], we present the first experimental evidence that the nonlinear self-interaction of a tidally forced inertial mode can drive an intense axisymmetric flow in a rotating deformed...

The effect of a background rotation on the decay of homogeneous turbulence produced by a grid is experimentally investigated. Experiments have been performed in a channel mounted in the large-scale 'Coriolis' rotating platform, and measurements have been carried out in the planes normal and parallel to the rotation axis using particle image velocim...

The scaling of the longitudinal velocity structure functions, $S_q(r) = < | \delta u (r) |^q > \sim r^{\zeta_q}$, is analyzed up to order $q=8$ in a decaying rotating turbulence experiment from a large Particle Image Velocimetry (PIV) dataset. The exponent of the second-order structure function, $\zeta_2$, increases throughout the self-similar deca...

Inertial waves generated by a small oscillating disk in a rotating water filled cylinder are observed by means of a corotating particle image velocimetry system. The wave takes place in a stationary conical wavepacket, whose angle aperture depends on the oscillation frequency. Direct visualisation of the velocity and vorticity fields in a plane nor...

The dynamics of the anisotropy of grid-generated decaying turbulence in a rotating frame is experimentally investi-gated by means of particle image velocimetry on the large-scale 'Coriolis' platform (LEGI, Grenoble). Turbulence is generated by rapidly towing a grid along a channel, providing a nearly homogeneous and isotropic initial state. Various...

The transition between isotropic 3D turbulence and anisotropic quasi-2D turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. We first describe t...

The energy decay of grid-generated turbulence in a rotating tank is experimentally investigated by means of particle image velocimetry. For times smaller than the Ekman time scale, a range of approximate self-similar decay is found, in the form u 2 t t −n , with the exponent n decreasing from 2 to values close to 1 as the rotation rate is increased...

The energy decay of grid-generated turbulence in a rotating tank is experimentally investigated by means of particle image velocimetry. For times smaller than the Ekman timescale, a range of approximate self-similar decay is found, in the form u2(t) / t¡n, with the exponent n decreasing from 2 to values close to 1 as the rotation rate is increased....

Decaying turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. A power-law decay of energy is observed up to the Ekman timescale, above which the...

The dynamics of the anisotropy of grid-generated decaying turbulence in a rotating frame is experimentally investigated by means of particle image velocimetry on the large-scale 'Coriolis' platform (LEGI, Grenoble). Turbulence is generated by rapidly towing a grid along a channel, providing a nearly homogeneous and isotropic initial state. Various...

The decay of initially three-dimensional homogeneous turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. During the decay, strong cyclonic cohe...

The theoretical investigation of edge and SOL plas ma turbulence indicates that the turbulence appears far less intermittent when the appropriate Log(N) fi eld is used. Diffusive flow transport shows that th e SOL parallel flow spreads into the core but exhibits a weak dependence on the Schmidt number. Conversely core flows strongly shifts the SOL...

La transition entre la turbulence tridimensionnelle et la turbulence quasi-bidimen- sionnelle sous l'effet d'une rotation d'ensemble estetudiee experimentalement. Un ´ ecoulement turbulent est genere par la translation d'une grille dans une cuve d'eau en rotation, et un systeme de velocimetrie par images de particules est utilisep our mesurer les c...

energie se d´ eveloppe aux grandes´ echelles. Abstract : The transition between three-dimensional and quasi-two-dimensional turbulence in a rotating frame is experimen- tally investigated. Turbulence is generated by towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of p...

Transition from three-dimensional to quasi-two-dimensional turbulence in a rotating frame is experimentally investigated. A decaying turbulent field is generated from oscillating a grid in a rotating water tank, and velocity measurements are performed using particle image velocimetry. The power spectrum, E(k), measured in the plane normal to the ro...

The transition between three-dimensional and quasi-two-dimensional turbulence in a rotating frame is experimentally investigated. Turbulence is generated by rapidly towing a grid in a rotating water tank, and the velocity field in a plane perpendicular to the rotation axis is measured by means of particle image velocimetry. During the decay, the po...