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[1] We describe laboratory experiments of granular material flowing over an inclined plane covered by an erodible bed, designed to mimic erosion processes of natural flows travelling over deposits built up by earlier events. Two controlling parameters are the inclination of the plane and the thickness of the erodible layer. We show that erosion processes(More)
  • F Bouchut, E D Fernández-Nieto, A Mangeney, P.-Y Lagrée
  • 2008
In this work we study the modeling of one-dimensional avalanche flows made of a moving layer over a static base, where the interface between the two can be time dependent. We propose a general model, obtained by looking for an approximate solution with constant velocity profile to the incompressible Euler equations. This model has an energy dissipation(More)
  • A Mangeney, F Bouchut, N Thomas, J P Vilotte, M O Bristeau
  • 2007
[1] When not laterally confined in valleys, pyroclastic flows create their own channel along the slope by selecting a given flowing width. Furthermore, the lobe-shaped deposits display a very specific morphology with high parallel lateral levees. A numerical model based on Saint Venant equations and the empirical variable friction coefficient proposed by(More)
[1] Recent experiments on dry granular flows over horizontal plane bare some similarities with large Martian landslides observed in Valles Marineris (VM). However, Martian normalized runout are twice as large as those that observed in dry granular flow experiments. Numerical simulations on theoretical 2D and real 3D topographies reconstructed from remote(More)
[1] The partial fluidization model developed by Aranson and Tsimring (2002) is used to simulate the spreading of a 2D circular cap of granular material over an erodible bed made of the same material. Numerical results show that the presence of even a very thin layer of granular material lying on the solid bed strongly increases the mobility of granular(More)
Numerical simulation can provide a useful tool for investigating the dynamics of phenomena like rock avalanches, within realistic geological contexts and in the framework of a better risk assessment and decision making. Difficulties in numerical modelling of a heterogeneous moving mass are mainly linked to the simulation of the complex behaviour assumed by(More)
In this paper we present a new two-layer model of Savage-Hutter type to study submarine avalanches. A layer composed of fluidized granular material is assumed to flow within an upper layer composed of an inviscid fluid (e. g. water). The model is derived in a system of local coordinates following a non-erodible bottom and takes into account its curvature.(More)
[1] Recent gullies on Mars are suspected to be the result of liquid‐water‐bearing flows. A formation from wet flows has been challenged by studies invoking granular (dry) flows. Our study focuses on the sinuous shapes observed for some of the recent Martian gullies. Sinuous gullies are found in locations and slopes (of 10°–15°) similar to straight gullies,(More)
Numerical simulations of collisionless supercritical quasi-perpendicular shocks suggest that the upstream whistlers may be generated near the shock by the reflected protons which gyrate back to the shock. We investigate in detail results of hybrid simulations and a linear theory for a gyrotropic gyrating beam in a Maxwellian plasma, and we compare their(More)
We present results of a two-dimensional hybrid simulation of the electromagnetic proton beam instability. We show that for a case of cold and rather high density proton beam the oblique right-handed resonant modes play an important role. The interaction of these modes with the beam protons causes significant beam density fluctuations. At the nonlinear stage(More)