Download or read book Methodes temps frequence appliquees a l analyse de signaux issus d ecoulements turbulents written by José Martinez (Professeur à l'École Polytechnique de Nantes) and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book M thodes temps fr quence appliqu es l analyse de signaux issus d coulements turbulents written by José Martinez (Professeur à l'École Polytechnique de Nantes) and published by . This book was released on 1994 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse présente une application originale à la mécanique des fluides des analyses temps-fréquence issues des décompositions linéaires continues (FOURIER à fenêtre glissante, ondelettes,...). Dans une première approche, on cherche à estimer les lois de modulation des composantes d'un signal à l'aide de la phase de la transformée. L'algorithme exposé permet ensuite de restreindre la représentation à des lignes caractéristiques, constituant la signature temps-fréquence du signal. Dans ce cadre "continu", on développe une extension temps-fréquence des fonctions de corrélation, basée sur le principe de ces décompositions linéaires. Dans une deuxième partie, on cherche à étendre et unifier ces transformations continues à l'aide d'un troisième paramètre d'échelle. La décomposition obtenue, non linéaire, permet d'extraire de manière itérative les composantes discrètes, localisées d'un signal en fonction d'un critère énergétique. Ces outils sont appliqués à deux cas expérimentaux. Le premier s'intéresse à un obstacle placé dans une conduite. On y quantifie l'intermittence et la fluctuation de la fréquence de détachement tourbillonnaire en fonction des conditions initiales et des perturbations amont. Le deuxième cas d'écoulemnt, de type diaphragme, se définit par une variation brutale de la section. On isole et quantifie les tourbillons individuellement, puis on suit, au cours de leur progression dans l'écoulement, l'évolution de l'échelle et de leur vitesse de convection. Cette approche permet de détecter des phénomènes d'appariements entre structures et de séparer l'influence des diverses perturbations de celle de l'aérodynamique.
Download or read book Laser Anemometry written by and published by . This book was released on 1995 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Numerical Flow Visualization 1995 written by and published by . This book was released on 1995 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyse de signaux et d images en turbulence 2D written by Zsolt-Andrei Peter and published by . This book was released on 2004 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le but de la thèse est l'analyse de simulations numériques directes de la turbulence bidimensionnelle dans un écoulement décrit par les équations de Navier-Stokes. Dans le traitement des données numériques (pression, vitesse et vorticité) on utilise des méthodes mathématiques combinées de traitement du signal et de l'image pour mieux comprendre le phénomène de la turbulence 2D. Le premier volet de l'étude porte sur l'analyse des signaux 1D en certain points de l'écoulement, tandis que le deuxième développe une analyse similaire pour les images de l'écoulement provenant de la même simulation. On a essayé de valider la coexistence des deux cascades dans le spectre d'énergie, prédit par Batchelor et Kraichnan. Parmi les techniques utilisées on compte l'analyse Fourier, les ondelettes et le modèle auto-régressif pour représenter et comparer le contenu des fréquences des signaux. On a réalisé une analyse temps-fréquences des données en utilisant l'algorithme de choix de la meilleur base des paquets d'ondelettes et cosinus. Ces fonctions de type paquets ont été aussi employées à la séparation de l'écoulement en parties significatives de point de vue physique. La méthode de la décomposition en valeurs singulières (POD), basée sur la théorie de Hilbert-Schmidt est aussi exploitée pour comprimer les donnés et pour localiser les structures cohérentes dans l'écoulement turbulent. Ces résultats ont été combinés dans le cadre de l'algorithme de matching-pursuit pour trouver les motifs d'écoulement qui sont cohérents avec un dictionnaire particulier (comme les paquets d'ondelettes et cosinus, fonction de Gabor, modes POD, modes prolate etc.).
Download or read book TRANSFORMEES EN ONDELETTES ANALYSES MULTIRESOLUTION ET SIGNAUX DE PRESSION EN TURBULENCE written by Patrice Abry and published by . This book was released on 1994 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE PREMIER CHAPITRE CONSTITUE UNE VISITE GUIDEE DE L'ANALYSE EN ONDELETTES. LES COMPARAISONS SYSTEMATIQUES DES DEFINITIONS ET PROPRIETES DES DIFFERENTES TRANSFORMEES, CONTINUE OU DISCRETE, PERMETTENT DE PROPOSER QUELQUES ELEMENTS DE REPONSE AUX QUESTIONS AUXQUELLES UN UTILISATEUR DEVRA FAIRE FACE LORS DE LA MISE EN UVRE DE CET OUTIL POUR L'ANALYSE DE SIGNAUX EXPERIMENTAUX: LE TEMPS-ECHELLE EST-IL LA REPONSE APPROPRIEE, QUELLE VARIANTE DE LA TRANSFORMEE EN ONDELETTES CHOISIR, QUELLE ONDELETTE, QUEL ALGORITHME EMPLOYER ? DANS LE DEUXIEME CHAPITRE, ON S'INTERESSE DAVANTAGE A L'ANALYSE MULTIRESOLUTION ET A LA POSSIBILITE DE DESSINER UNE INFINIE VARIETE D'ONDELETTES (SEMI-, BI-) ORTHOGONALES, QUI CORRESPONDENT A DES MOTIFS D'ANALYSE CHOISIS A PRIORI. LE TROISIEME CHAPITRE PROPOSE TROIS CATEGORIES D'APPLICATIONS POUR LESQUELLES LA PERTINENCE DES COEFFICIENTS DE LA TRANSFORMEE EN ONDELETTES COMME ESPACE DE REPRESENTATION EST DISCUTEE ET PARTICULIEREMENT SOULIGNEE: ESTIMATION SPECTRALE DEDIEE AUX PROCESSUS EN 1/F ; DETECTION DE TRANSITOIRES LARGE-BANDE ; ANALYSE DE PHENOMENES DE LONGUE DEPENDANCE DANS LES PROCESSUS PONCTUELS. ON PRESENTE ENFIN, DANS LE DERNIER CHAPITRE, LES RESULTATS OBTENUS, A L'AIDE D'ANALYSE TEMPS-ECHELLE, SUR DES SIGNAUX DE PRESSION ISSUS D'UNE EXPERIENCE DE TURBULENCE DEVELOPPEE. ON CARACTERISE NOTAMMENT UN CERTAIN NOMBRE DE PROPRIETES DES FILAMENTS DE VORTICITE, STRUCTURES COHERENTES PRESENTES DANS LES ECOULEMENTS TURBULENTS. ON ETUDIE AUSSI LE PHENOMENE D'INTERMITTENCE EN GOMMANT, DANS LES SIGNAUX, LES DEPRESSIONS. POUR CELA, ON MANIPULE LES COEFFICIENTS DE LA DECOMPOSITION EN ONDELETTES COINCIDENTS AVEC LE PASSAGE DE CES DEPRESSIONS
Download or read book REPRESENTATIONS TEMPS FREQUENCE ET DECISION APPLICATION A L ANALYSE VIBRO ACOUSTIQUE written by ANTOINE.. MOINEAU and published by . This book was released on 1997 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE TRAVAIL PRESENTE DANS CE MEMOIRE CONCERNE L'UTILISATION DE METHODES TEMPS-FREQUENCE, DEVELOPPEES DANS UN CADRE NON STATIONNAIRE, POUR L'ANALYSE DE SIGNAUX VIBRATOIRES OU ACOUSTIQUES ET POUR LA DETECTION D'EVENTUELS DEFAUTS DE FONCTIONNEMENT DANS LES MACHINES GENERANT CE TYPE DE SIGNAUX. EN PREMIERE PARTIE, NOUS PRESENTONS LES FONDEMENTS DE BASE DE L'ANALYSE TEMPS-FREQUENCE NON PARAMETRIQUE. NOUS RETRACONS LES DEUX GRANDES DIRECTIONS CONDUISANT A UNE REPRESENTATION TEMPS-FREQUENCE D'UN SIGNAL, A SAVOIR LES DECOMPOSITIONS ATOMIQUES ET LES DISTRIBUTIONS D'ENERGIE. LA DEUXIEME PARTIE EST CONSACREE A LA THEORIE DE LA DECISION. APRES UN RAPPEL DES PRINCIPES DE BASE CONDUISANT A UN SYSTEME DE DECISION, NOUS DONNONS LES DIFFERENTES STRATEGIES OPTIMALES DE DETECTION DE SIGNAUX OBTENUES DANS UN CADRE PUREMENT TEMPOREL, AINSI QUE LA FACON DE LES INTEGRER DANS UN SYSTEME DE RECONNAISSANCE DE FORME. LA TROISIEME PARTIE REPREND LE PROBLEME DE LA DECISION DONT LA FORMULATION EST CETTE FOIS DONNEE DANS UN CADRE TEMPS-FREQUENCE. NOUS PRESENTONS EGALEMENT ICI UNE STRUCTURE GENERALE QUE PEUT ADOPTER UN SYSTEME DE CLASSIFICATION A BASE DE TRANSFORMATIONS TEMPS-FREQUENCE. LES DIFFERENTES ETAPES INTERNES A CE SYSTEME SONT ENSUITE DETAILLEES. LA QUATRIEME PARTIE REGROUPE LA PARTIE EXPERIMENTALE DE CE TRAVAIL. NOUS PRESENTONS PREALABLEMENT LES OUTILS LOGICIELS DEVELOPPES POUR LA MISE EN UVRE DES TECHNIQUES ETUDIEES PRECEDEMMENT. ENSUITE DEUX APPLICATIONS D'ANALYSE TEMPS-FREQUENCE DE SIGNAUX VIBRATOIRES DE MACHINES TOURNANTES SONT ENVISAGEES, L'UNE CONCERNANT UN LAVE LINGE, L'AUTRE UN COMPRESSEUR INDUSTRIEL. ENFIN, UNE APPLICATION DES METHODES DE DECISION A BASE DE REPRESENTATIONS TEMPS-FREQUENCE EST REALISEE POUR LA DETECTION ET LA CLASSIFICATION DE DEFAUTS A PARTIR DES SIGNAUX ACOUSTIQUES ISSUS D'UNE TURBINE DE SECHAGE DE LAVE-LINGE.
Download or read book A Parallel Finite Volume Algorithm for Large eddy Simulation of Turbulent Flows written by Trong T. Bui and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Boundary Layer Theory written by Hermann Schlichting (Deceased) and published by Springer. This book was released on 2016-10-04 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1989 with total page 1182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rheology of Complex Fluids written by Abhijit P. Deshpande and published by Springer Science & Business Media. This book was released on 2010-09-20 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the School on Rheology of Complex fluids is to bring together young researchers and teachers from educational and R&D institutions, and expose them to the basic concepts and research techniques used in the study of rheological behavior of complex fluids. The lectures will be delivered by well-recognized experts. The book contents will be based on the lecture notes of the school.
Download or read book Production of Juvenile Atlantic Salmon Salmo Salar in Natural Waters written by National Research Council Canada and published by NRC Research Press. This book was released on 1993 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up-to-date information, knowledge and research in progress in scientific fields related to natural production of juvenile Atlantic salmon and some other ecologically similar fluvial salmonids is contained in the 25 papers and 12 abstracts contained in this publication, which were prepared for an international symposium held in St. John's, Newfoundland. Studies relate to stream ecology, invertebrates and predators, habitat improvement, competitive effects, behaviour and dispersal, habitat and production of juvenile salmon, population dynamics and relationships of juvenile salmon estimates to smolt yields. A list of participants at the conference is also provided.
Download or read book Hydraulic Power System Analysis written by Arthur Akers and published by CRC Press. This book was released on 2006-04-17 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: The excitement and the glitz of mechatronics has shifted the engineering community's attention away from fluid power systems in recent years. However, fluid power still remains advantageous in many applications compared to electrical or mechanical power transmission methods. Designers are left with few practical resources to help in the design and
Download or read book Design and Modeling of Mechanical Systems written by Mohamed Haddar and published by Springer Science & Business Media. This book was released on 2013-03-12 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 5th International Congress on Design and Modeling of Mechanical Systems (CMSM) was held in Djerba, Tunisia on March 25-27, 2013 and followed four previous successful editions, which brought together international experts in the fields of design and modeling of mechanical systems, thus contributing to the exchange of information and skills and leading to a considerable progress in research among the participating teams. The fifth edition of the congress (CMSM ́2013), organized by the Unit of Mechanics, Modeling and Manufacturing (U2MP) of the National School of Engineers of Sfax, Tunisia, the Mechanical Engineering Laboratory (MBL) of the National School of Engineers of Monastir, Tunisia and the Mechanics Laboratory of Sousse (LMS) of the National School of Engineers of Sousse, Tunisia, saw a significant increase of the international participation. This edition brought together nearly 300 attendees who exposed their work on the following topics: mechatronics and robotics, dynamics of mechanical systems, fluid structure interaction and vibroacoustics, modeling and analysis of materials and structures, design and manufacturing of mechanical systems. This book is the proceedings of CMSM ́2013 and contains a careful selection of high quality contributions, which were exposed during various sessions of the congress. The original articles presented here provide an overview of recent research advancements accomplished in the field mechanical engineering.
Download or read book Advances in Hydroinformatics written by Philippe Gourbesville and published by Springer. This book was released on 2015-08-21 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of extended papers based on presentations given during the SIMHYDRO 2014 conference, held in Sophia Antipolis in June 2014. It focuses on the modeling and simulation of fast hydraulic transients, on 3D modeling, and on uncertainties and multiphase flows. The book explores both the limitations and performance of current models and presents the latest developments based on new numerical schemes, high-performance computing, multiphysics and multiscale methods, and better interaction with field or scale model data. It addresses the interests of practitioners, stakeholders, researchers and engineers active in this field.
Download or read book Microreaction Technology written by M. Matlosz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: IMRET 5 featured more than 80 oral and poster communications, covering the entire interdisciplinary field from design, production, modeling and characterization of microreactor devices to application of microstructured systems for production, energy and transportation, including many analytical and biological applications. A particularly strong topic was the investigation of the potential of microstructuring of reactors and systems components for process intensification. Perspectives of combining local, in situ, data acquisition with appropriate microstructuring of actuators and components within chemical and biological devices were explored in order to enhance process performance and facilitate process control.
Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
