Étude des Modèles de Turbulence sur une Aile d'Avion (original) (raw)
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Study of the turbulence models over an aircraft wing
Incertitudes et fiabilité des systèmes multiphysiques, 2018
L'aérodynamique est définie comme la science de la manipulation d'un fluide qui est souvent l'air en interaction avec une structure. Lors de la simulation de l'écoulement au-dessus des pales aérodynamiques, la transition d'un écoulement laminaire à un écoulement turbulent joue un rôle important dans la détermination des caractéristiques d'écoulement et dans la quantification des performances de la surface portante telles que la portance et la traînée. Ces flux fluidiques sont soumis à des contraintes visqueuses et à une inertie qui produit des fluctuations désordonnées. La turbulence affecte donc le comportement du flux aérodynamique ainsi que la structure en interaction avec un fluide pour des nombres de Reynolds élevés. En effet, il est nécessaire de contrôler ces flux turbulents dans ce domaine afin de donner une bonne conception de la structure. Plusieurs modèles de turbulence ont été développés pour faciliter le calcul des grandeurs caractéristiques afin d'optimiser la simulation des écoulements turbulents en aérodynamique. Dans cet article, nous avons présenté une validation d'une simulation numérique d'un écoulement transsonique 3D sur l'aile ONERA M6 pour laquelle les résultats numériques, réalisés avec ANSYS/FLUENT ©, seront comparés à des données expérimentales et à des résultats numériques de la NASA portant sur le coefficient de pression (Cp) le long des surfaces des ailes supérieures et inférieures. Le flux a été obtenu en résolvant les équations de conservation de la masse et de la quantité de mouvement en régime permanent, combinées à l'un des cinq modèles de turbulence (Spalart-Allmaras (S-A), k-ε standard, k-ε RNG, k-ω standard et k-ω SST) visant à la validation de ces modèles par la comparaison des prévisions et des mesures expérimentales en champ libre pour l'aile sélectionnée.
On Turbulence Modelling and the Transition from Laminar to Turbulent Flow
The ANZIAM Journal, 2014
Fluid turbulence is often modelled using equations derived from the Navier–Stokes equations, perhaps with some semi-heuristic closure model for the turbulent viscosity. This paper considers a possible alternative hypothesis. It is argued that regarding turbulence as a manifestation of non-Newtonian behaviour may be a viewpoint of at least comparable validity. For a general description of nonlinear viscosity in a Stokes fluid, it is shown that the flow patterns are indistinguishable from those predicted by the Navier–Stokes equation in one- or two-dimensional geometry, but that fully three-dimensional flows differ markedly. The stability of linearized plane Poiseuille flow to three-dimensional disturbances is then considered, in a Tollmien–Schlichting formulation. It is demonstrated that the flow may become unstable at significantly lower Reynolds numbers than those expected from Navier–Stokes theory. Although similar results are known in sections of the rheological literature, the p...
Special issue of the “Turbulence and Interaction-TI2006” conference
Computers & Fluids, 2008
During the conference, many contributions showed substantial video animations giving some deep insight into the very different interaction phenomena. The conference also provided strong evidence that the three pillars of science, namely theory, experiments and computing, through their interplay come to achieving progress in understanding and predicting the physics of complicated flows and engineering problems.
2009
Prevoir la transition laminaire-turbulent de la couche limite sur l'avant-corps d'un vehicule hypersonique est importantpour optimiser l'entree d'air du superstatoreacteur qui lui est associe, mais reste tres difficile apres un demi-siecle derecherches intensives sur le sujet. Dans ce travail, les approches numeriques et experimentales sont mises en oeuvre etcomparees. Experimentalement, la transition naturelle est detectee a Mach 4 et Mach 6 dans la soufflerie continue T-313de l'ITAM a Novossibirsk a l'aide de mesures de pression Pitot. Dans une autre soufflerie de l'ITAM, la AT-303 a rafale,on a detecte la transition naturelle a Mach 6 et la transition declenchee par rugosites a Mach 8 a l'aide d'un procedeoptique base sur l'emploi de peintures thermosensibles. Ces essais ont ete realises sur maquette a echelle 1/3. Toutesles rugosites testees se sont montrees efficaces. La prevision theorique de la transition naturelle a ete realisee au moy...
Papers and abstracts of the international conference Advances in Turbulence VIII
2005
The Universitat Politecnica de Catalunya at the Vilanova i la Geltru Campus (EPSViG) organizes the VIII ADVANCES IN TURBULENCE International conference as the main periodic event of the Xarxa Tematica de Dinamica de Fluids i Turbulencia Geofisica during 24-26 November 2005. This series of conferences started in 1992 with a small meeting of 50 participants held at UPC Barcelona which grew steadily. Advances in Turbulence 4, held in Barcelona in October 1998 had 117 participants from 18 countries and was strongly suported by CNRS, Advances in Turbulence 5 was held at the Universitat de Girona in June 1999 with more than 100 participants, Advances in Turbulence 6 was presented within the wider scope EUROMECH European Turbulence Conference with more than 500 Participants at the Vertex Auditorium in Barcelona, and Advances in Turbulence 7 was held during 21-23 November 2003 in Vilanova i la Geltru with 100 participants. The conference site is a human sized coastal village with many attractive lures to the visitor including food, sights and leisure. The Advances in Turbulence 8 conference will take place hosted by the Campus Universitari de la Mediterrania and the UPC at the Moli de Mar building, near the lighthouse beach. We welcome all participants to discuss and present their latest work on turbulent flows, mixing, chaotic dynamics and complex systems. The Proceedings Special Issue will be published in English (although presentations and abstracts may be given both in English and French). The full paper if accepted and presented at the conference will be reviewed in either Word or Tex Kluwer templates. All handling of the papers will be electronic and published likely as an special issue after the conference with the participant list. XARXA DFTG (Fluid Dynamics and Geophysical Turbulence ) as well as ERCOFTAC SIGS Representing members of the XARXA TEMATICA DE DINAMICA DE FLUIDS I TURBULENCIA GEOFISICA groups are invited to present their main advances in turbulence since the last meeting in 2003. Invited speakers at the conference are . C. Yague (Univ. Complutense Madrid), J. M. Redondo (UPC, Barcelona ) A. Platonov (Hidromet. Institute. St. Petersburg / UPC), J. L. Pelegri / A Viudez (CSIC, ICM Barcelona), B. Fleck (Univ. Alberta, Canada). P. Arnau (Univ. Barcelona) . An Acrylic Painting exhibition, together with the poster session on Shapes and Patterns in the Environment and a young scientist session related to the European Science week will complement the meeting. See www.campusmed.net for updated information. We also thank CUM and Gencat support.
2010
Director, A&E Trounev IT Consulting, Toronto, Canada В работе представлена полностью замкнутая мо-дель турбулентного пограничного слоя , получен-ная из уравнения Навье -Стокса . Фундаментальные константы пристенной турбулентности , включая постоянную Кармана , определены из теории . Эта модель была развита для ускоренного и неизотер-мического пограничного слоя над шероховатой поверхностью The completely closed model of wall turbulence was derived directly from the Navier-Stokes equation. The fundamental constants of wall turbulence including the Karman constant have been calculated within a theory. This model has been developed also for the accelerated and non-isothermal turbulent boundary layer flows over rough surface Ключевые слова : АТМОСФЕРНАЯ ТУРБУЛЕНТНОСТЬ , ТУРБУЛЕНТНЫЙ ПЕРЕНОС , УСКОРЕННЫЕ ТЕЧЕНИЯ , ПОГРАНИЧНЫЙ СЛОЙ , ШЕРОХОВАТАЯ ПОВЕРХНОСТЬ , ПРИЗЕМНЫЙ СЛОЙ АТМОСФЕРЫ , ТУРБУЛЕНТНЫЙ ПЕРЕНОС АЭРОЗОЛЕЙ Keywords: ACCELERATED FLOW, AEROSOL TURBULENT TRANSPORT, ATMOSPHERIC STRAT...
From pre-turbulent flows to fully developed turbulence
In colloquial speech the term "turbulence" means any flow with complicated temporal and spatial dynamics. In contrast, the properties of these flows are supposed to be described by models which are based on the assumption of a precise and very well defined setting. This paper is an attempt to review the fundamentals of turbulence theory, with emphasis on non-fully developed turbulence.
Some developments in the theory of turbulence
Journal of Fluid Mechanics, 1981
This is in no way intended as a review of turbulence-the subject is far too big for adequate treatment within a reasonably finite number of pages; the monumental ' closure ' scheme brings no guarantee of better predictions outside the range of geometries and parameters previously documented, then it is of little value to the user. Sometimes a user may suffer from the delusion that a more ' advanced ' closure scheme must, merely by virtue of its complexity, provide a better representation of the effects