June, 4th 2010 - Numerical fluid mechanics and modeling

Titre/Title: Challenges in simulations of hydraulic turbomachinery

Résumé:

Abstratct: Even though hydraulic turbines exist for centuries, a considerable effort in research and development is still dedicated to hydraulic turbomachinery, especially in the field of numerical simulation, so called CFD, not forgetting experimental research that moves in parallel with CFD. This is related to the high performances that are now expected from these turbines, and also from the deregulated market that induces a more “dynamic” operation of hydraulic turbines, especially in our European countries. For example, significant efforts are dedicated to the understanding of transient operations, with the support of CFD, and to fluid-structure interactions studies. The CFD state of the art in hydraulic turbomachinery is illustrated for all types of turbines, including multiphase flows with novel meshless methods, with a special focus on fluid structure analyses and transient modes. The tools and methods applied for post-processing and visualization are also considered.

Titre/Title: Uncertainty quantification for CFD - The NODESIM-CFD project

Résumé:

Abstract: The introduction of uncertainties in CFD simulations opens a new approach to analysis and design. It requires new methodologies for stochastic PDE's (SPDE) with stochastic input parameters, including geometries. The NODESIM-CFD project has generated results of significant interest, comparing different (Monte-Carlo, Sensitivity analysis, Polynomial Chaos) on test cases with preset uncertainties. New paradigms for validation and experiments are presented.

Titre/Title:Méthodes de couplage de modèles / Model coupling methods

Résumé: De nombreux problèmes de modélisation en hydraulique nécessitent l'’usage combiné de modèles qui peuvent différer simplement par leurs emprises géographiques, leurs résolutions, ou plus généralement par leurs contenus physiques. Suivant les cas, on a affaire à un problème de frontière ouverte, d'’imbrication de modèles, ou encore de couplage multi-physique. On passera en revue dans cet exposé ces différentes problématiques, en indiquant les principales méthodes permettant d'’aborder ces questions, basées sur des outils comme les conditions aux limites absorbantes, les méthodes de Schwarz, ou encore des approches variationnelles.

Abstract: Numerous modelling problems in hydraulics require the joint use of models that can differ by their geographical extent, their resolution, or more generally by their physical contents. Depending on the cases, this leads to an open boundary problem, a nesting problem or a multiphysics coupling problem. In this talk, we will review these different types of problems, and indicate the main approaches to tackle them, based on tools like absorbing boundary conditions, Schwarz domain decomposition method, or variational tools.

Incertitudes dans les simulations 3D / Uncertainties in 3D simulations

Eric VALETTE and Namane MECHITOUA
Choix d’un code de calcul pour une simulation 3D

Frédéric LAUGIER, Benoît BLANCHER and Gregory GUYOT
Analyse des Incertitudes attachées aux résultats des simulations numériques 3D pour le calcul de la débitance des évacuateurs de crue

Gislain LIPEME KOUYI and Jean-Luc BERTRAND KRAJEWSKI
3D Modelling of flows in a large detention and settling basin

Ecoulements turbulents et complexes / Turbulent and complex flows

François KERGER and Benjamin DEWALS
Modélisation des écoulements mixtes diphasiques hautement transitoires

Nicolas CHINI
Influence of bed slope effects on the morphology of mound in oscillatory flows

Mani MEHDINIA and Bahar FIROOZABADI
Large Eddy simulation of the evolution of a gravity current propagating over a backward facing step

Modélisation maritime et cotière / Ocean and coastal modelling

Julien SCHAGUENE, Bertrand OLIVIER and David ERIC
Etude de la compatibilité de la zone de recouvrement des modèles numériques - applications aux études d'impact des projets d'énergies marines

Annie FIANDRINO and Nicolas JEANNEE
Assessment of Escherichia coli- contamination in the Thau lagoon (France): combined use of physically based modeling and geostatistics

Nicolas PERENNE and Marc PAVEC
On the use of Seamer-3D in a Costal Operational Oceanography system

Catherine HEYRAUD, Philippe CRANEGUY and Pierre GARREAU
Vers une caractérisation des sources d’erreurs de prévisions dans le modèle d’hydrodynamique côtière régionale MARS3-D

Hydrodynamique / Hydrodynamics

Hossein RIAHI MADVAR
Uncertainty analysis of ANN and ANFIS techniques in comparison with sediment equations for predicting bed load transport

Nisrine ALDERF, Emmanuel LEFRANCOIS and Philippe SERGENT
Prédiction numérique de surenfoncement dynamique d’un navire avec prise en compte des effets transitoires

Sebastien ERPICUM, Benjamin DEWALS, Pierre ARCHAMBEAU and Michel PIROTTON
Reliable hydraulic numerical modeling with multiblock grids and linked

Sima SAFARKHANI and Mahmood BORGHEI
Dynamic pressure fluctuations on a trapezoidal plunge pools due to jet impacts

Modélisation maritime et cotière / Ocean and coastal modelling

Maziar GOLESTANI, Alireza KEBRIAEE, Hajji HAFEDH and Scott ROWE
A Comparison of Coastal Wave Models in the Persian Gulf

Rowe SCOTT, Hafedh HAJJI, Farhad DARABI NIA and M.R.ALLAH YAR
Variability of different atmospheric forcings for hydrodynamic models in the Persian Gulf

Hydraulique et méthodes numériques / Hydraulics and numerical methods

Nicolas PERENNE
Long-term fate of salt intrusions at a ship lock Propagation des incertitudes en modélisation hydraulique des rivières

Sébastien ERPICUM, Olivier MACHIELS, Pierre ARCHAMBEAU, Benjamin DEWALS and Michel PIROTTON
Modélisation numérique 1D des écoulements sur un déversoir en touches de piano (PKW)