Michel O. Deville
École Polytechnique Fédérale de Lausanne
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Featured researches published by Michel O. Deville.
Journal of Biomechanics | 1996
Cheng Tu; Michel O. Deville
The problem of blood flow through stenoses is solved using the incompressible generalized Newtonian model. The Herschel-Bulkley, Bingham and power-law fluids are incorporated. The geometry corresponds to a rigid circular tube with a partial occlusion. Calculations are performed by a Galerkin finite-element method. For the pulsatile case, a predictor-corrector time marching scheme is used with an adaptive time step. Results are obtained for steady and pulsatile physiological flows. Computations show that the memory effects taken into account in the model affect deeply the flow compared with Newtonian reference case. The disturbances are stronger by their vorticity intensity and persist after the geometrical obstacle. This is especially true for severe stenoses.
AIAA Journal | 2002
Eric Garnier; Pierre Sagaut; Michel O. Deville
Reference LIN-ARTICLE-2002-008View record in Web of Science Record created on 2007-05-22, modified on 2016-08-08
Siam Journal on Scientific and Statistical Computing | 1990
Michel O. Deville; Ernest Mund
A preconditioning technique for pseudospectral solutions of elliptic problems based on quadrangular finite-element algorithms is analyzed, which exhibits excellent convergence properties. The pseudospectral technique is implemented through a collocation grid based on Gauss–Lobatto quadrature nodes associated to the Jacobi orthogonal polynomials. Various types of basis functions are used in the finite-element preconditioner (i.e., low-order Lagrange or cubic Hermite elements). Dirichlet and Neumann problems are investigated in one- and two-space dimensions. Numerical results show that the eigenvalue spectrum of the iteration matrix is inside the unit circle and even, close to zero for a wide range of operators. This property ensures convergence until roundoff error level in a few iterations. The differences between finite-element and finite-difference preconditioning are analyzed. Finally, the application of the algorithm to a problem exhibiting geometric induced singularities is discussed.
Journal of Non-newtonian Fluid Mechanics | 1997
Gilmar Mompean; Michel O. Deville
Abstract The equations for viscoelastic flows of an Oldroyd-B fluid are integrated using the finite volume technique. The numerical algorithm was developed to treat three-dimensional (3D) unsteady flows using Cartesian coordinates on a non-uniform staggered grid. The primitive variables, velocities, pressure and extra-stresses are used in the formulation. All inertia terms in the momentum and constitutive equations are taken into account and are discretized in space using a quadratic upwind scheme. Case studies have been conducted for the start-up Couette flow, two-dimensional (2D) 4:1 and 3D 4:1:4 planar contractions. The numerical solutions agree very well with analytical solutions for the start-up Couette flow. The size of the corner vortex for the 4:1 planar contraction, in the 2D case, is in good agreement with previous computations. Comparison between 2D calculation for a qualitative analysis, using the Oldroyd-B fluid, and measurements [1] of at 5.0 wt.% solution of polyisobutylene in tetradecane, is presented for the velocity and normal stress difference at several cross sections in the planar contraction. New results showing the vector field, streamlines and extra-stress components are presented for a 3D 4:1:4 planar contraction at high Deborah numbers (27.3).
Physics of Fluids | 2007
Roland Bouffanais; Michel O. Deville; Emmanuel Leriche
Large-eddy simulations of the turbulent flow in a lid-driven cubical cavity have been carried out at a Reynolds number of 12000 using spectral element methods. Two distinct subgrid-scales models, namely a dynamic Smagorinsky model and a dynamic mixed model, have been both implemented and used to perform long-lasting simulations required by the relevant time scales of the flow. All filtering levels make use of explicit filters applied in the physical space (on an element-by-element approach) and spectral (modal) spaces. The two subgrid-scales models are validated and compared to available experimental and numerical reference results, showing very good agreement. Specific features of lid-driven cavity flow in the turbulent regime, such as inhomogeneity of turbulence, turbulence production near the downstream corner eddy, small-scales localization and helical properties are investigated and discussed in the large-eddy simulation framework. Time histories of quantities such as the total energy, total turbulen...
Physics of Fluids | 1996
G. Mompean; S. Gavrilakis; L. Machiels; Michel O. Deville
Low turbulent Reynolds number direct simulation data are used to calculate the invariants of the Reynolds stress and the turbulent dissipation rate in a square duct. The results show that, depending on the region where the analysis is carried out, the turbulent flow field comes close to one‐, two‐, and three‐component states. Modeling such flows—even at higher Reynolds numbers—will require models that can approach all three states. A number of related nonlinear k‐e models are tested a priori using the direct simulation data. The numerical simulation using Reynolds averaged Navier–Stokes equations with these models was performed. Their ability to predict the secondary flows, with a low‐Reynolds k‐e model, cannot be gauged from realizability.
Archive | 2012
Michel O. Deville; Thomas B. Gatski
Mathematical Modeling for Complex Fluids and Flows provides researchers and engineering practitioners encountering fluid flows with state-of-the-art knowledge in continuum concepts and associated fluid dynamics. In doing so it supplies the means to design mathematical models of these flows that adequately express the engineering physics involved. It exploits the implicit link between the turbulent flow of classical Newtonian fluids and the laminar and turbulent flow of non-Newtonian fluids such as those required in food processing and polymeric flows. The book develops a descriptive mathematical model articulated through continuum mechanics concepts for these non-Newtonian, viscoelastic fluids and turbulent flows. Each complex fluid and flow is examined in this continuum context as well as in combination with the turbulent flow of viscoelastic fluids. Some details are also explored via kinetic theory, especially viscoelastic fluids and their treatment with the Boltzmann equation. Both solution and modeling strategies for turbulent flows are laid out using continuum concepts, including a description of constructing polynomial representations and accounting for non-inertial and curvature effects. Ranging from fundamental concepts to practical methodology, and including discussion of emerging technologies, this book is ideal for those requiring a single-source assessment of current practice in this intricate yet vital field.
Computers & Fluids | 2002
Eric Garnier; Pierre Sagaut; Michel O. Deville
Large Eddy simulation (LES) of shock/homogeneous turbulence have been performed at two different Mach numbers (1.2 and 2) with four different subgrid scale (SGS) models (Smagorinsky model, mixed scale model, dynamic Smagorinsky model, dynamic mixed model). The code was successfully validated by comparisons with the direct numerical solutions (DNS) results of Lee et al. and, from a numerical point of view, the hybrid flux approach presented here exhibits a very satisfactory behaviour. The general conclusion of this study is that LES is efficient for such an interaction only if the mesh is fine enough in the shock vicinity to capture shock corrugation. Even with such a requirement, LES reduces dramatically the computational effort necessary to simulate the shock/homogeneous turbulence interaction with respect to DNS. Dynamic SGS models are found to improve markedly the quality of the results when compared to simple models like Smagorinskys
Computers & Fluids | 2000
Ivan Mary; Pierre Sagaut; Michel O. Deville
An algorithm is proposed for the simulation of unsteady viscous compressible subsonic flows at low Mach number. The method is second-order accurate both in space and time. To remove the stiffness of the numerical problem due to the large disparity between the flow and the acoustic wave speeds, an adaptation of the artificial compressibility method is proposed in order to preserve the possibility to simulate standard subsonic applications. After a detailed description of the method, the scheme is applied to the unsteady incompressible numerical benchmark of the Poiseuille-Benard channel flow in order to validate the possibility to simulate stratified flow without Boussinesq approximation. Next, the efficiency of the method, compared with Runge-Kutta (RK) scheme, is evaluated thanks to the advection of a Lamb vortex at reference Mach number, M o , 0.8 and 0.001.
Journal of Scientific Computing | 2006
Roland Bouffanais; Michel O. Deville; Paul F. Fischer; Emmanuel Leriche; Daniel Weill
This paper presents the large-eddy simulation of the lid-driven cubic cavity flow by the spectral element method (SEM) using the dynamic model. Two spectral filtering techniques suitable for these simulations have been implemented. Numerical results for Reynolds number Re=12,000 are showing very good agreement with other experimental and DNS results found in the literature.