Publications associées à Méthode des volumes finis

A cut-cell method for the numerical simulation of 3D multiphase flows with strong interfacial effects

Marco Picasso, Alexandre Caboussat, Julien Hess, Alexandre Masserey

We present a numerical model for the approximation of multiphase flows with free surfaces and strong interfacial effects. The model relies on the multiphase incompressible Navier-Stokes equations, and includes surface tension effects on the interfaces betw ...

Academic Press Inc Elsevier Science2024

Stochastic Simulations and Machine Learning Modeling to Predict Bedload Transport and Bed Topography

Mehrdad Kiani Oshtorjani

In computational hydraulics models, predicting bed topography and bedload transport with sufficient accuracy remains a significant challenge. An accurate assessment of a river's sediment transport rate necessitates a prior understanding of its bed topograp ...

EPFL2024

Numerical Study of the Optical Response of ITO-In2O3 Core-Shell Nanocrystals for Multispectral Electromagnetic Shielding

Michele Ghini, Nicolò Petrini

Nowadays materials to protect equipment from unwanted multispectral electromagnetic waves are needed in a broad range of applications including electronics, medical, military and aerospace. However, the shielding materials currently in use are bulky and wo ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Pathways to enhance electrochemical CO2 reduction identified through direct pore-level modeling

Sophia Haussener, Etienne Boutin, Shuo Liu, Evan Fair Johnson

Electrochemical conversion of CO2 to fuels and valuable products is one pathway to reduce CO2 emissions. Electrolyzers using gas diffusion electrodes (GDEs) show much higher current densities than aqueous phase electrolyzers, yet models for multi-physical ...

2023

An element-based formulation for ES-FEM and FS-FEM models for implementation in standard solid mechanics finite element codes for 2D and 3D static analysis

Slah Drira

Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear eleme ...

Wiley2022

Numerical simulations of Pelton turbine flow to predict large head variation influence

François Avellan, Cécile Münch-Alligné, Siamak Alimirzazadeh, Steve Crettenand

In the framework of the new feed-in-tariff system in Switzerland for Small Hydropower Plants (SHP), the aim of the SmallFLEX project, led by HES-SO Valais and performed in collaboration with EPFL, WSL, EAWAG, PVE, and FMV, is to show how SHP can provide wi ...

IOP PUBLISHING LTD2021

A Method for the Improvement of the Stability in FDTD-Based Numerical Codes Evaluating Lightning-Induced Voltage

Farhad Rachidi-Haeri

Dealing with realistic networks, the solution of lightning electromagnetic field coupling to transmission lines is generally obtained through a Finite-Difference Time-Domain (FDTD) algorithm interfaced with an electromagnetic simulator. As well known, the ...

2021

Evaluation of Site Errors in LLS Magnetic Direction Finding Caused by Large Hills Using the 3D‐FDTD Technique

Farhad Rachidi-Haeri, Wolfgang Schulz, Hannes Kohlmann

Angle and amplitude estimation errors in magnetic direction finding, called site errors, are important sensor-specific errors in lightning location systems (LLS). They are known to be caused by nearby cables and overhead lines due to induced currents. Due ...

2021

Numerical methods for conservation laws with rough flux

Hakon Andreas Hoel

Finite volume methods are proposed for computing approximate pathwise entropy/kinetic solutions to conservation laws with flux functions driven by low-regularity paths. For a convex flux, it is demonstrated that driving path oscillations may lead to "cance ...

2020

High-order essentially nonoscillatory methods based on radial basis functions

Fabian Mönkeberg

Essentially nonoscillatory (ENO) and weighted ENO (WENO) methods on equidistant Cartesian grids are widely employed to solve partial differential equations with discontinuous solutions. However, stable ENO/WENO methods on unstructured grids are less well s ...

EPFL2020

Development and verification of pin-by-pin homogenized simplified transport solver Tortin for PWR core analysis

Andreas Pautz, Petra Mala

Currently, the pin-by-pin homogenized solvers are a very active research field as they can, unlike the nodal codes, directly predict the local power, while requiring significantly less computational resources than the heterogeneous transport codes. This pa ...

2020

Numerical Framework for Aerodynamic Characterization of Wind Turbine Airfoils: Application to Miniature Wind Turbine WiRE-01

Fernando Porté Agel, Tristan Revaz, Mou Lin

A numerical framework for the aerodynamic characterization of wind turbine airfoils is developed and applied to the miniature wind turbine WiRE-01. The framework is based on a coupling between wall-resolved large eddy simulation (LES) and application of th ...

2020

A Local Discontinuous Galerkin Method for Two-Dimensional Time Fractional Diffusion Equations

Jan Sickmann Hesthaven, Reza Mokhtari

For two-dimensional (2D) time fractional diffusion equations, we construct a numerical method based on a local discontinuous Galerkin (LDG) method in space and a finite difference scheme in time. We investigate the numerical stability and convergence of th ...

SPRINGERNATURE2020

Propagation of fluid driven fractures in transversely isotropic material

Fatima-Ezzahra Moukhtari

The propagation of fluid driven fractures is used in a number of industrial applications (well stimulation of unconventional reservoirs, development of deep geothermal systems) but also occurs naturally (magmatic dyke intrusion). While the mechanics of hyd ...

EPFL2020

A multiphase CMAQ version 5.0 adjoint

Athanasios Nenes

We present the development of a multiphase adjoint for the Community Multiscale Air Quality (CMAQ) model, a widely used chemical transport model. The adjoint model provides location- and time-specific gradients that can be used in various applications such ...

2020

Compact high order finite volume method on unstructured grids IV: Explicit multi-step reconstruction schemes on compact stencil

Qian Wang

In the present paper, a multi-step reconstruction procedure is proposed for high order finite volume schemes on unstructured grids using compact stencil. The procedure is a recursive algorithm that can eventually provide sufficient relations for high order ...

2019

Unsteady Radiative Heat Transfer Model of a Ceria Particle Suspension Undergoing Solar Thermochemical Reduction

Sophia Haussener, Aldo Steinfeld, Tristan Elias Breuillé

Unsteady radiative heat transfer is analyzed numerically in a directly irradiated plane-parallel medium containing a suspension of ceria particles undergoing nonstoichiometric thermal reduction. The micrometer-sized ceria particles are assumed homogenous, ...

AMER INST AERONAUTICS ASTRONAUTICS2019

On the representation of thin wires inside lossy dielectric materials for FDTD‐based LEMP simulations

Farhad Rachidi-Haeri, Marcos Rubinstein, Akiyoshi Tatematsu

The finite-difference time-domain method is one of the most widely used numerical electromagnetic computation techniques, and it has become an effective tool for analyzing electromagnetic transient phenomena in three-dimensional structures and grounding sy ...

2019

Sparse Spline Approximation on the Hypersphere by Generalised Total Variation Basis Pursuit

Matthieu Martin Jean-André Simeoni

Many scientific inquiries in natural sciences involve approximating a spherical field –namely a scalar quantity defined over a continuum of directions– from generalised samples of the latter. Typically, a convex optimisation problem is formulated in terms ...

2019

Entropy stable essentially non-oscillatory methods based on RBF reconstructions

Jan Sickmann Hesthaven, Fabian Mönkeberg

To solve hyperbolic conservation laws on general grids we propose to use high-order essentially nonoscillatory methods based on radial basis functions. We introduce an entropy stable arbitrary high-order finite dierence method (RBF-TeCNOp) and an entropy s ...

2019