Simulation Des Grandes Echelles en Elements Finis Stabilisés

Simulation Des Grandes Echelles en Elements Finis Stabilisés

Author: Vincent Levasseur

Publisher: Omniscriptum

Published: 2011-04

Total Pages: 156

ISBN-13: 9786131572166

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L'objectif des travaux est d'étudier la Simulation des Grandes Echelles dans un contexte industriel aéronautique. La dissipation numérique inhérente aux codes industriels robustes nécessite des modèles sous-mailles capables de s'ajuster pour calculer la viscosité turbulente adéquate. L'approche Variational MultiScale de Hughes et al. est développée en régime compressible sous une formulation filtrée, puis implantée en variables entropiques dans le solveur éléments finis AETHER de DASSAULT-AVIATION. Des études de décroissance libre de turbulence isotrope ont montré d'excellentes propriétés du modèle. Cette technique est ensuite appliquée aux écoulements compressibles au-dessus d'une cavité ouverte. Deux dispositifs de contrôle passif sont étudiés: un spoiler et un barreau cylindrique. Si un effet commun est de dévier et d'épaissir la couche de cisaillement se développant au-dessus de la cavité, il est montré que les mécanismes de contrôle sous-jacents sont très différents.


Simulation des grandes échelles en éléments finis stabilisés

Simulation des grandes échelles en éléments finis stabilisés

Author: Vincent Levasseur

Publisher:

Published: 2007

Total Pages: 204

ISBN-13:

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L'objectif des travaux est d'étudier la Simulation des Grandes Echelles dans un contexte industriel aéronautique. La dissipation numérique inhérente aux codes industriels robustes nécessite des modèles sous-mailles capables de s'ajuster pour calculer la viscosité turbulente adéquate. L'approche Variational MultiScale de Hughes et al. est développée en régime compressible sous une formulation filtrée, puis implantée en variables entropiques dans le solveur éléments finis AETHER de DASSAULT-AVIATION. Des études de décroissance libre de turbulence isotrope ont montré d'excellentes propriétés du modèle. Cette technique est ensuite appliquée aux écoulements compressibles au-dessus d'une cavité ouverte. Deux dispositifs de contrôle passif sont étudiés : un spoiler et un barreau cylindrique. Si un effet commun est de dévier et d'épaissir la couche de cisaillement se développant au-dessus de la cavité, il est montré que les mécanismes de contrôle sous-jacents sont très différents.


DESider – A European Effort on Hybrid RANS-LES Modelling

DESider – A European Effort on Hybrid RANS-LES Modelling

Author: Werner Haase

Publisher: Springer Science & Business Media

Published: 2009-05-12

Total Pages: 469

ISBN-13: 3540927735

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Preface “In aircraft design, efficiency is determined by the ability to accurately and rel- bly predict the occurrence of, and to model the development of, turbulent flows. Hence, the main objective in industrial computational fluid dynamics (CFD) is to increase the capabilities for an improved predictive accuracy for both complex flows and complex geometries”. This text part taken from Haase et al (2006), - scribing the results of the DESider predecessor project “FLOMANIA” is still - and will be in future valid. With an ever-increasing demand for faster, more reliable and cleaner aircraft, flight envelopes are necessarily shifted into areas of the flow regimes exhibiting highly unsteady and, for military aircraft, unstable flow behaviour. This undou- edly poses major new challenges in CFD; generally stated as an increased pred- tive accuracy whist retaining “affordable” computation times. Together with highly resolved meshes employing millions of nodes, numerical methods must have the inherent capability to predict unsteady flows. Although at present, (U)RANS methods are likely to remain as the workhorses in industry, the DESider project focussed on the development and combination of these approaches with LES methods in order to “bridge” the gap between the much more expensive (due to high Reynolds numbers in flight), but more accurate (full) LES.


Terra 2008

Terra 2008

Author: Leslie Rainer

Publisher: Getty Publications

Published: 2011-06-14

Total Pages: 438

ISBN-13: 1606060430

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Earthen architecture constitutes one of the most diverse forms of cultural heritage and one of the most challenging to preserve. It dates from all periods and is found on all continents but is particularly prevalent in Africa, where it has been a building tradition for centuries. Sites range from ancestral cities in Mali to the palaces of Abomey in Benin, from monuments and mosques in Iran and Buddhist temples on the Silk Road to Spanish missions in California. This volume's sixty-four papers address such themes as earthen architecture in Mali, the conservation of living sites, local knowledge systems and intangible aspects, seismic and other natural forces, the conservation and management of archaeological sites, research advances, and training.


High Performance Concrete

High Performance Concrete

Author: Y. Malier

Publisher: CRC Press

Published: 2018-05-08

Total Pages: 570

ISBN-13: 1351440896

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Provides a thorough review of properties, durability and use of high performance concrete, derived from recent research and experience. This book contains contributions from the leading French, Canadian and Swiss researchers, designers and material specialists, translated into English for the first time.


Noncommutative Geometry

Noncommutative Geometry

Author: Alain Connes

Publisher: Springer

Published: 2003-12-15

Total Pages: 364

ISBN-13: 3540397027

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Noncommutative Geometry is one of the most deep and vital research subjects of present-day Mathematics. Its development, mainly due to Alain Connes, is providing an increasing number of applications and deeper insights for instance in Foliations, K-Theory, Index Theory, Number Theory but also in Quantum Physics of elementary particles. The purpose of the Summer School in Martina Franca was to offer a fresh invitation to the subject and closely related topics; the contributions in this volume include the four main lectures, cover advanced developments and are delivered by prominent specialists.