https://hal.archives-ouvertes.fr/hal-00294092/document

Three-dimensional Large Eddy Simulation of air entrainment under plunging breaking waves

https://personal.egr.uri.edu/grilli/Abadieetal-CE-2010.pdf

Numerical simulation of waves generated by landslides using a multiple-fluid Navier–Stokes model

Towards large eddy simulation of isothermal two-phase flows: Governing equations and a priori tests

Numerical simulation of phase separation and a priori two-phase LES filtering

We present here some contributions to the numerical analysis of the penalty method in the finite element context. We are especially interested in the ability provided by this approach to use Cartesian, non boundary-fitted meshes to solve elliptic problems in complicated domain. In the spirit of fictitious domains, the initial problem is replaced by a penalized one, posed over a simply shaped domain which covers the original one. This method relies on two parameters, namely $h$ (space-discretization parameter) and $\varepsilon$ (penalty parameter). We propose here a general strategy to estimate the error in both parameters, and we present how it can be applied to various situations. We pay special attention to a scalar version of the rigid motion constraint for fluid-particle flows.

/pdf/numerical-analysis-of-a-finite-element-volume-penalty-method-1wi3sq9f50.pdf

Numerical Analysis of a Finite Element/Volume Penalty Method

An adaptative augmented Lagrangian method for three-dimensional multimaterial flows

Local penalty methods for flows interacting with moving solids at high Reynolds numbers

The numerical modelling of fluidized bed is widely encountered in fundamental research and industrial applications in the field of chemistry, energy or material processes The problem is complicated by the presence of different length and time scales describing the particles and the reactors Several modellings exist for simulating particulate flows In averaged Eulerian models where the size of the particles is small compared to the continuous medium characteristic scale, fluid-particle interactions are taken into account using constitutive laws In the present study, a numerical model is proposed to describe the fluid-particle interactions at the particle scale, based on fixed Eulerian structured grids, penalty methods and Volume Of Fluid (VOF) techniques Our interest is to build a general model and approximation methods efficient enough for leading Direct Numerical Simulations of particulate flows without any requirements of physical parametrization such as particle-particle interactions In addition, our motivation is to analyze the results of the numerical experiments in terms of equivalent macroscopic quantities such as velocity fluctuations, granular pressure or solid fraction Fluidized beds are characterized by thousands of particles interacting in a moving fluid Solving such fluid/particle motion at the particle scale can be achieved thanks to two main approaches First, the conservation equations can only be solved in the fluid phase and the grid is adapted in a Lagrangian manner at each calculation step to account for the particle shape In three dimensional unsteady problems, this method is too expansive in calculation time and difficult to implement The second approach consists in solving the fluid-solid two-phase flow on a fixed Eulerian grid This method is easy to develop for complex and evolving topologies of the two phases However, the conservation equations must take into account the discontinuous and unsteady behavior of the flow characteristics

A DNS Approach Dedicated to the Analysis of Fluidized Beds

La strategie de modelisation numerique de la bibliotheque de calcul scientifique Aquilon developpee sur des grilles fixes Euleriennes sera presentee en pretant attention au traitement implicite des equations de conservation, aux methodes de penalisation pour diverses contraintes, aux algorithmes pour le suivi d'interface (de type Volume Of Fluid) et aux methodes automatiques et adaptatives de raffinement de maillage (AMR). Les validations detaillees seront proposees pour illustrer l'ordre de convergence et la consistance des methodes numeriques, et des validations physiques bi et tridimensionnelles seront developpees avec des comparaisons a des resultats experimentaux ou theoriques. En conclusion, plusieurs exemples de simulations d'ecoulements diphasiques reels seront donnes comme des mouvements de lit fluidise, le deferlement de vagues, l'essorage d'un film sous l'action d'un jet turbulent ou le processus de remplissage d'un moule. Les resultats seront discutes par rapport a des references experimentales ou industrielles et critiques par exemple par rapport au modele de turbulence et a son couplage avec la surface libre.

Tseheno Nirina Randrianarivelo

Papers

An adaptative augmented Lagrangian method for three-dimensional multimaterial flows

Local penalty methods for flows interacting with moving solids at high Reynolds numbers

A DNS Approach Dedicated to the Analysis of Fluidized Beds

Implicit penalty methods on eulerian grids for the simulation of incompressible multiphase flows