Marie-Odile Bristeau
University of Paris
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Publication
Featured researches published by Marie-Odile Bristeau.
Journal of Geophysical Research | 2007
Anne Mangeney; François Bouchut; N Thomas; Jean-Pierre Vilotte; Marie-Odile Bristeau
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 Pouliquen and Forterre (2002) is used to simulate unconfined granular flow over an inclined plane with a constant supply. Numerical simulations successfully reproduce the self-channeling of the granular lobe and the levee-channel morphology in the deposits without having to take into account mixture concepts or polydispersity. Numerical simulations suggest that the quasi-static shoulders bordering the flow are created behind the front of the granular material by the rotation of the velocity field due to the balance between gravity, the two-dimensional pressure gradient, and friction. For a simplified hydrostatic model, competition between the decreasing friction coefficient and increasing surface gradient as the thickness decreases seems to play a key role in the dynamics of unconfined flows. The description of the other disregarded components of the stress tensor would be expected to change the balance of forces. The fronts shape appears to be constant during propagation. The width of the flowing channel and the velocity of the material within it are almost steady and uniform. Numerical results suggest that measurement of the width and thickness of the central channel morphology in deposits in the field provides an estimate of the velocity and thickness during emplacement.
Mathematics of Computation | 2016
Emmanuel Audusse; François Bouchut; Marie-Odile Bristeau; Jacques Sainte-Marie
A lot of well-balanced schemes have been proposed for discretizing the classical Saint-Venant system for shallow water flows with non-flat bottom. Among them, the hydrostatic reconstruction scheme is a simple and efficient one. It involves the knowledge of an arbitrary solver for the homogeneous problem (for example Godunov, Roe, kinetic,...). If this solver is entropy satisfying, then the hydrostatic reconstruction scheme satisfies a semi-discrete entropy inequality. In this paper we prove that, when used with the classical kinetic solver, the hydrostatic reconstruction scheme also satisfies a fully discrete entropy inequality, but with an error term. This error term tends to zero strongly when the space step tends to zero, including solutions with shocks. We prove also that the hydrostatic reconstruction scheme does not satisfy the entropy inequality without error term.
Archive | 2002
A. Mangeney-Castelnau; J.P. Vilotte; Marie-Odile Bristeau; François Bouchut; Benoît Perthame; Chiara Simeoni; S. Yernini
Archive | 2017
S. Allgeyer; Marie-Odile Bristeau; D. Froger; Raouf Hamouda; Anne Mangeney; Jacques Sainte-Marie; Fabien Souillé; M. Vallée
Archive | 2018
Marie-Odile Bristeau; Bernard Di Martino; Anne Mangeney; Jacques Sainte-Marie; Fabien Souillé
Archive | 2018
David Demory; Charlotte Combe; Philipp Hartmann; Amélie Talec; Eric Pruvost; Raouf Hamouda; Fabien Souillé; Pierre-Olivier Lamare; Marie-Odile Bristeau; Jacques Sainte-Marie; Sophie Rabouille; Francis Mairet; Antoine Sciandra; Olivier Bernard
Archive | 2017
Nora Aïssiouene; Marie-Odile Bristeau; Edwige Godlewski; Anne Mangeney; Carlos Parés; Jacques Sainte-Marie
Archive | 2017
Fabien Souillé; Marie-Odile Bristeau; Jacques Sainte-Marie
Archive | 2017
Fabien Souillé; Marie-Odile Bristeau; Jacques Sainte-Marie
Archive | 2016
Marie-Odile Bristeau; David Froger; Raouf Hamouda; Anne Mangeney; Jacques Sainte-Marie; Martin Vallée