Modélisation statistique du bruit de jets en vue d'applications à la propulsion aéronautique
Title | Modélisation statistique du bruit de jets en vue d'applications à la propulsion aéronautique PDF eBook |
Author | Nicolas Héron |
Publisher | |
Pages | 145 |
Release | 2002 |
Genre | |
ISBN |
Pour estimer les principales contributions au rayonnement acoustique, des expressions semi-analytiques sont déduites de la solution intégrale de l'équation de Lighthill selon différents formalismes. Les modèles établis à partir de ces expressions exploitent les solutions de calculs aérodynamiques. Ces calculs sont réalisés par un code résolvant les équations de Navier-Stokes moyennées et fermées par un modèle de turbulence. On dispose ainsi d'une description du comportement moyen de l'écoulement et d'une représentation statistique de sa turbulence. Ces données servant d'entrée au code de calcul de bruit, elles ont été soumises à des études paramétriques. On a ainsi évalué la modélisation de la turbulence et son impact sur les prévisions aérodynamiques et acoustiques. L’influence du maillage sur les mêmes résultats a aussi été examinée. Ces études ont également permis de déterminer des conditions aux limites adéquates pour les calculs de l'écoulement, en particulier dans le cas des jets chauffés. Au cours de ces études un mailleur a été écrit pour générer des grilles de résolution parfaitement adaptées au calcul d'écoulements libres en sortie de tuyère. La méthodologie développée est d'abord utilisée pour évaluer la réduction du bruit de mélange pour des configurations double flux, selon des vitesses d'éjection des deux jets. La méthode est ensuite exploitée dans une étude des possibilités d'élimination des ondes de Match générées par un jet supersonique. Cette élimination est envisagée par l'addition d'un jet secondaire dont on ajuste les conditions d'éjection en température et en vitesse. Une description complète des termes sources acoustiques est ensuite réalisée pour prendre en compte le rayonnement associé à des différentiels de température entre le jet et le milieu ambiant. Le modèle réalisé à partir de cette description a été validé sur l'étude du bruit de jets chauds supersoniques.
Advances in Rotorcraft Technology
Title | Advances in Rotorcraft Technology PDF eBook |
Author | North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Flight Vehicle Integration Panel. Symposium |
Publisher | |
Pages | 402 |
Release | 1997 |
Genre | Helicopters |
ISBN |
Routledge International Handbook of Ignorance Studies
Title | Routledge International Handbook of Ignorance Studies PDF eBook |
Author | Matthias Gross |
Publisher | Routledge |
Pages | 427 |
Release | 2015-05-15 |
Genre | Business & Economics |
ISBN | 1317964675 |
Once treated as the absence of knowledge, ignorance today has become a highly influential topic in its own right, commanding growing attention across the natural and social sciences where a wide range of scholars have begun to explore the social life and political issues involved in the distribution and strategic use of not knowing. The field is growing fast and this handbook reflects this interdisciplinary field of study by drawing contributions from economics, sociology, history, philosophy, cultural studies, anthropology, feminist studies, and related fields in order to serve as a seminal guide to the political, legal and social uses of ignorance in social and political life. Chapter 33 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license available here: https://tandfbis.s3-us-west-2.amazonaws.com/rt-files/docs/Open+Access+Chapters/9780415718967_oachapter33.pdf
In-Vessel Melt Retention and Ex-Vessel Corium Cooling: IAEA Tecdoc No. 1906
Title | In-Vessel Melt Retention and Ex-Vessel Corium Cooling: IAEA Tecdoc No. 1906 PDF eBook |
Author | International Atomic Energy Agency |
Publisher | International Atomic Energy Agency |
Pages | 72 |
Release | 2020-08-06 |
Genre | Technology & Engineering |
ISBN | 9789201063205 |
This publication results from a technical meeting on phenomenology and technologies relevant to in-vessel melt retention (IVMR) and ex-vessel corium cooling (EVCC). The purpose of the publication is to capture the state of knowledge, at the time of that meeting, related to phenomenology and technologies as well as the challenges and pending issues relevant to IVMR and EVCC for water cooled reactors by summarizing the information provided by the meeting participants in a form useful to practitioners in Member States.
Advances in Hydroinformatics
Title | Advances in Hydroinformatics PDF eBook |
Author | Philippe Gourbesville |
Publisher | Springer |
Pages | 616 |
Release | 2015-08-21 |
Genre | Science |
ISBN | 9812876154 |
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.
MILCOM 2005
Title | MILCOM 2005 PDF eBook |
Author | Institute of Electrical and Electronics Engineers |
Publisher | |
Pages | 674 |
Release | 2005 |
Genre | |
ISBN |
Aerospace power in the twenty-first century a basic primer
Title | Aerospace power in the twenty-first century a basic primer PDF eBook |
Author | Clayton K. S. Chun |
Publisher | DIANE Publishing |
Pages | 351 |
Release | 2001 |
Genre | Air power |
ISBN | 1428990291 |
Dr. Chun's Aerospace Power in the Twenty-First Century: A Basic Primer is a great start towards understanding the importance of aerospace power and its ability to conduct modern warfare. Aerospace power is continually changing because of new technology, threats, and air and space theories. However, many basic principles about aerospace power have stood the test of time and warfare. This book provides the reader with many of these time-tested ideas for consideration and reflection. Although Aerospace Power in the Twenty-First Century was written for future officers, individuals desiring a broad overview of aerospace power are invited to read, share, and discuss many of the ideas and thoughts presented here. Officers from other services will find that this introduction to air and space forces will give them a good grasp of aerospace power. More experienced aerospace leaders can use this book to revisit many of the issues that have affected air and space forces in the past and that might affect them in the future. Air Force officers will discover that Aerospace Power in the Twenty-First Century is a very timely and reflective resource for their professional libraries.