Marie-Odile Bristeau

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We consider the Saint-Venant system for shallow water flows, with nonflat bottom. It is a hyperbolic system of conservation laws that approximately describes various geophysical flows, such as rivers, coastal areas, and oceans when completed with a Coriolis term, or granular flows when completed with friction. Numerical approximate solutions to this system(More)
The aim of this paper is to present a finite volume kinetic method to compute the transport of a passive pollutant by a flow modeled by the shallow water equations using a new time discretization that allows large time steps for the pollutant computation. For the hydrodynamic part the kinetic solver ensures – even in the case of a non flat bottom – the(More)
In the framework of a better territory risk assessment and decision making, numerical simulation can provide a useful tool for investigating the propagation phase of phenomena involving granular material, like rock avalanches, when realistic geological contexts are considered. Among continuum mechanics models, the numerical model SHWCIN uses the depth(More)
We consider the numerical investigation of two hyperbolic shallow water models. We focus on the treatment of the hyperbolic part. We first recall some efficient finite volume solvers for the classical Saint-Venant system. Then we study their extensions to a new multilayer Saint-Venant system. Finally, we use a kinetic solver to perform some numerical tests(More)
We discuss the application of an augmented conjugate gradient to the solution of a sequence of linear systems of the same matrix appearing in an iterative process for the solution of scattering problems. The conjugate gradient method applied to the first system generates a Krylov subspace, then for the following systems, a modified conjugate gradient is(More)
In this paper, we present an original derivation process of a nonhydrostatic shallow water-type model which aims at approximating the incompressible Euler and Navier-Stokes systems with free surface. The closure relations are obtained by a minimal energy constraint instead of an asymptotic expansion. The model slightly differs from the well-known(More)
Despite the large volume of information circulating in radiology departments, very few of them are currently computerised, although computer processing is developing rapidly in hospitals, encouraged by the installation of PMSI. This article illustrates the example of an imaging department management software: CASTOR-Radiologie, Computerisation of part of(More)