Principles of Computational Fluid Dynamics

Author: Pieter Wesseling
Publisher: Springer Science & Business Media
ISBN: 9783642051456
Release Date: 2009-12-21
Genre: Mathematics

This up-to-date book gives an account of the present state of the art of numerical methods employed in computational fluid dynamics. The underlying numerical principles are treated in some detail, using elementary methods. The author gives many pointers to the current literature, facilitating further study. This book will become the standard reference for CFD for the next 20 years.

Numerische Simulation des Ger usches massiv abgel ster Str mung bei gro er Reynoldszahl und kleiner Machzahl

Author: Knacke, Thilo
Publisher: Universitätsverlag der TU Berlin
ISBN: 9783798327351
Release Date: 2015-03-04
Genre: Technology & Engineering

Strömungsinduzierte Geräusche stellen heute ein zunehmendes Problem dar, besonders in der Umgebung von Flughäfen. Eine flächendeckende Lärmminderung ließe sich hier in erster Linie durch konstruktive Maßnahmen zur Abschwächung der wesentlichen Schallentstehungsmechanismen am Flugzeug erzielen. Dies setzt jedoch voraus, dass verlässliche aeroakustische Vorhersagen getroffen werden können, wozu nicht nur präzise Berechnungsverfahren für die Schallausbreitung, sondern auch für das mittlere Strömungsfeld und für die aerodynamischen Geräuschquellen erforderlich sind. In der vorliegenden Arbeit wird ein im Bereich subsonischer Strömungssimulationen etabliertes, druckbasiertes 3D-Finite-Volumen-Verfahren für den Einsatz in aeroakustischen Grobstruktursimulationen weiterentwickelt. Der hier vordergründig betrachtete Strömungszustand und Kennzahlbereich ist typisch für das Entstehen von „airframe noise“, aerodynamischem Lärm, welcher primär durch die turbulente Umströmung von Fahrwerk und Hochauftriebshilfen startender oder landender Flugzeuge verursacht wird. Die Kopplung von kompressiblen Grobstruktursimulationen im Quellgebiet mit nachgeschalteten akustischen Extrapolationen ermöglicht eine Berechnung dieser Umströmungsgeräusche bis ins Fernfeld. Nach kurzer Darstellung der physikalischen Grundlagen und verschiedener Möglichkeiten zur numerischen Simulation wird das ausgewählte Verfahren im Detail analysiert und eine Schwachstelle in der zur Berechnung der Massenflüsse eingesetzten Interpolation nach Rhie & Chow identifiziert. Der Schwerpunkt der Weiterentwicklung liegt anschließend auf der sorgfältigen Herleitung einer Familie konsistenter Approximationen zur Bestimmung von Massenflüssen über Kontrollvolumengrenzflächen auf nichtversetzten Gittern. Zwei neue Varianten der Massenflussberechnung werden in das bestehende Druckkorrekturverfahren integriert. Deren Verhalten wird im Vergleich zur ursprünglichen Implementierung an einem akademischen Testfall bewertet. Es folgt eine Abstimmung von Numerik und Feinstrukturmodell am Zerfall isotroper Turbulenz und nach der Qualifizierung des verbesserten Verfahrens schließlich dessen Anwendung zur Berechnung von Strömungsgeräuschen an einer generischen Fahrwerksverstrebung und an einer 3-Komponenten-Hochauftriebskonfiguration. Die Ergebnisse dieser Simulationen weisen überwiegend eine sehr gute Übereinstimmung mit experimentell ermittelten Daten auf. Auf Basis einer aeroakustischen Analyse der hochaufgelösten Simulationsergebnisse am Vorflügel gelingt letztlich ein statistischer Nachweis für den dort dominierenden Schallentstehungsmechanismus. Flow-induced noise represents an increasing problem today, particularly in the vicinity of airports. Comprehensive aircraft noise reduction could primarily be achieved through design changes which mitigate the major noise generation mechanisms. However, such changes require reliable aeroacoustic predictions, which is only possible if appropriate numerical tools are available. These must allow the precise calculation of the sound and mean flow fields as well as the most relevant aerodynamic noise sources. In this work a pressure-based 3D finite volume method, which is already well-established in the area of subsonic flow computation, is further developed in order to enable its application for aeroacoustic large-eddy simulations. The flow state and the range of similarity parameters considered here are chosen to be representative of typical airframe noise. This is mainly caused by separated flow around deployed landing gear and high-lift devices during aircraft takeoff and landing. The coupling of compressible large-eddy simulations in the main sound source regions with subsequent acoustic extrapolations provides access to the prediction of such aerodynamic noise up to the farfield. The selected method is analysed in detail following a brief overview of the physical background and state-of-the-art numerical simulation techniques. A weak point is identified in the Rhie & Chow interpolation which is employed for the calculation of mass fluxes. Particular emphasis is then placed on the careful derivation of a family of consistent approximations for the determination of mass flux over control volume faces on co-located grids. Two new flux formulations are integrated into the existing pressure correction method. Their behaviour is validated and compared to that of the original implementation on an academic test case. Following a thorough reassessment of the balance between numerical and modelled dissipation on the decay of isotropic turbulence, the improved method is finally applied to compute the flow-induced noise around a generic two-struts configuration and around a three-component high-lift configuration. The simulation results predominantly exhibit very good agreement with experimental data. Based on highly-resolved flow field data acquired from the simulation of the high-lift system, a concise aeroacoustic analysis is offered. Statistical evidence of the dominant noise generation mechanism near a leading edge slat is provided.

Bauphysik Kalender 2015

Author: Nabil A. Fouad
Publisher: John Wiley & Sons
ISBN: 9783433605165
Release Date: 2015-05-26
Genre: Technology & Engineering

Die technische Komplexität von Gebäuden hat massiv zuggenommen. Fast alle Bereiche der Gebäudetechnik sind heute zumindest teilweise automatisiert, um z. B. das Raumklima zu optimieren, den Energieverbrauch zu senken, Brand- und Rauchentwicklung frühzeitig zu erkennen und zu unterbinden und im Ganzen eine kostengünstigere Bewirtschaftung zu ermöglichen. Numerische Simulationsverfahren sind daher aus der Gebäudeplanung und im Bestand nicht mehr wegzudenken und werden auf allen Gebieten der Bauphysik eingesetzt. Ihre Anwendung erfordert Hintergrundwissen zu den verwendeten Berechnungsverfahren, um sie wirtschaftlich einzusetzen und Fehler zu vermeiden. Auch die Modellgenauigkeit spielt für die Interpretation von Simulationsergebnissen eine bedeutende Rolle und wird häufig unterschätzt, ihre Verifikation muss nachvollziehbar sein. Außerdem sind aufgrund von Vereinfachungen manche Ergebnisse nur für bestimmte Parameter brauchbar. Nicht zuletzt erfordert die Anwendung und Interpretation von Simulationen auch die Berücksichtigung von eventuellen Ungenauigkeiten der Eingabeparameter. Der Bauphysik-Kalender 2015 gibt wertvolle Praxishinweise zur Softwareanwendung anhand von Beispielen.

Numerische Str mungsmechanik

Author: Joel H. Ferziger
Publisher: Springer-Verlag
ISBN: 9783540682288
Release Date: 2008-05-14
Genre: Science

Das Buch bietet einen Überblick über die numerischen Methoden zur Lösung strömungsmechanischer Probleme. Die in der Praxis meistgenutzten Methoden werden detailliert beschrieben. Behandelt werden auch fortgeschrittene Methoden, wie die Simulation von Turbulenzen und Parallel-Verarbeitung. Das Buch beschreibt die Grundlagen und Prinzipien der verschiedenen Methoden. Numerische Genauigkeit und Abschätzung sowie Fehlerreduktion werden detailliert mit vielen Beispielen behandelt. Alle Computercodes sind über den Server ftp.springer.de des Springer-Verlages erhältlich (Internet).

Boundary value problems for transonic flow

Author: Alexander G Kuz'min
Publisher: John Wiley & Sons Inc
ISBN: 0471486418
Release Date: 2002-07-29
Genre: Mathematics

Transonic flow occurs around moving objects as they approach and cross the sound barrier. Serious problems can occur at this point, such as shock-induced flow separation which can cause the aircraft to spin out of control. Another important practical problem is the achievement of higher aerodynamic performance of aircraft at cruise conditions, which leads to considerable fuel savings. The success in application of numerical methods for simulation of transonic flow and aircraft design depends on developments in the underlying mathematical theory. This book presents a breakthrough in the solvability analysis of boundary value problems, which makes it possible to establish convergence of finite element approximations for shock-free flow and to provide a framework for putting the existing numerical methods on a more sound basis. Also, physical aspects concerned with patterns of formation and propagation of weak shock waves are analysed. This contributes to the understanding of the extreme sensitivity of transonic flow to perturbation of freestream conditions. The developed theoretical knowledge base yields promising concepts of the airfoil design and active flow control by airfoil/wing shape modifications or suction/blowing through a perforated surface. Boundary Value Problems for Transonic Flow * Focuses on Computational Fluid Dynamics. * Addresses practical problems, such as airfoil design and flow control. * Presents developments made in the last two decades. In essence this is a much needed monograph for researchers and engineers in applied mathematics and numerical analysis applied to aerodynamics and for algorithm developers in Computational Fluid Dynamics in the aircraft industry. It gives design engineers the underlying mathematical theory necessary for developing new concepts for airfoil/wing design and flow control.

RAIRO

Author: EDP Sciences
Publisher:
ISBN: UOM:39015072634507
Release Date: 2008
Genre: Numerical analysis


Slow Viscous Flow

Author: William E. Langlois
Publisher: Springer Science & Business Media
ISBN: 9783319038353
Release Date: 2014-04-15
Genre: Mathematics

Leonardo wrote, “Mechanics is the paradise of the mathematical sciences, because by means of it one comes to the fruits of mathematics”; replace “Mechanics” by “Fluid mechanics” and here we are. - From the Preface to the Second Edition Although the exponential growth of computer power has advanced the importance of simulations and visualization tools for elaborating new models, designs and technologies, the discipline of fluid mechanics is still large, and turbulence in flows remains a challenging problem in classical physics. Like its predecessor, the revised and expanded Second Edition of this book addresses the basic principles of fluid mechanics and solves fluid flow problems where viscous effects are the dominant physical phenomena. Much progress has occurred in the half a century that has passed since the edition of 1964. As predicted, aspects of hydrodynamics once considered offbeat have risen to importance. For example, the authors have worked on problems where variations in viscosity and surface tension cannot be ignored. The advent of nanotechnology has broadened interest in the hydrodynamics of thin films, and hydromagnetic effects and radiative heat transfer are routinely encountered in materials processing. This monograph develops the basic equations, in the three most important coordinate systems, in a way that makes it easy to incorporate these phenomena into the theory. The book originally described by Prof. Langlois as "a monograph on theoretical hydrodynamics, written in the language of applied mathematics" offers much new coverage including the second principle of thermodynamics, the Boussinesq approximation, time dependent flows, Marangoni convection, Kovasznay flow, plane periodic solutions, Hele-Shaw cells, Stokeslets, rotlets, finite element methods, Wannier flow, corner eddies, and analysis of the Stokes operator.

Basics of Fluid Mechanics and Introduction to Computational Fluid Dynamics

Author: Titus Petrila
Publisher: Springer Science & Business Media
ISBN: 9780387238388
Release Date: 2006-06-14
Genre: Mathematics

The present book – through the topics and the problems approach – aims at filling a gap, a real need in our literature concerning CFD (Computational Fluid Dynamics). Our presentation results from a large documentation and focuses on reviewing the present day most important numerical and computational methods in CFD. Many theoreticians and experts in the field have expressed their - terest in and need for such an enterprise. This was the motivation for carrying out our study and writing this book. It contains an important systematic collection of numerical working instruments in Fluid Dyn- ics. Our current approach to CFD started ten years ago when the Univ- sity of Paris XI suggested a collaboration in the field of spectral methods for fluid dynamics. Soon after – preeminently studying the numerical approaches to Navier–Stokes nonlinearities – we completed a number of research projects which we presented at the most important inter- tional conferences in the field, to gratifying appreciation. An important qualitative step in our work was provided by the dev- opment of a computational basis and by access to a number of expert softwares. This fact allowed us to generate effective working programs for most of the problems and examples presented in the book, an - pect which was not taken into account in most similar studies that have already appeared all over the world.

Optimization and Computational Fluid Dynamics

Author: Dominique Thévenin
Publisher: Springer Science & Business Media
ISBN: 3540721533
Release Date: 2008-01-08
Genre: Technology & Engineering

The numerical optimization of practical applications has been an issue of major importance for the last 10 years. It allows us to explore reliable non-trivial configurations, differing widely from all known solutions. The purpose of this book is to introduce the state-of-the-art concerning this issue and many complementary applications are presented.

Characteristics Finite Element Methods in Computational Fluid Dynamics

Author: Joe Iannelli
Publisher: Springer Science & Business Media
ISBN: 9783540453437
Release Date: 2006-09-24
Genre: Science

This book details a systematic characteristics-based finite element procedure to investigate incompressible, free-surface and compressible flows. Several sections derive the Fluid Dynamics equations from first thermo-mechanics principles and develop this multi-dimensional and infinite-directional upstream procedure by combining a finite element discretization with an implicit non-linearly stable Runge-Kutta time integration for the numerical solution of the Euler and Navier Stokes equations.

Design and Management of Sustainable Built Environments

Author: Runming Yao
Publisher: Springer Science & Business Media
ISBN: 9781447147817
Release Date: 2013-03-12
Genre: Technology & Engineering

Climate change is believed to be a great challenge to built environment professionals in design and management. An integrated approach in delivering a sustainable built environment is desired by the built environment professional institutions. The aim of this book is to provide an advanced understanding of the key subjects required for the design and management of modern built environments to meet carbon emission reduction targets. In Design and Management of Sustainable Built Environments, an international group of experts provide comprehensive and the most up-to-date knowledge, covering sustainable urban and building design, management and assessment. The best practice case studies of the implementation of sustainable technology and management from the BRE Innovation Park are included. Design and Management of Sustainable Built Environments will be of interest to urban and building designers, environmental engineers, and building performance assessors. It will be particularly useful as a reference book for undergraduate and postgraduate students in the built environment field.

Bioreaction Engineering Principles

Author: Jens Nielsen
Publisher: Springer
ISBN: 9781461507673
Release Date: 2012-12-06
Genre: Technology & Engineering

This is the second edition of the text "Bioreaction Engineering Principles" by Jens Nielsen and John Villadsen, originally published in 1994 by Plenum Press (now part of Kluwer). Time runs fast in Biotechnology, and when Kluwer Plenum stopped reprinting the first edition and asked us to make a second, revised edition we happily accepted. A text on bioreactions written in the early 1990's will not reflect the enormous development of experimental as well as theoretical aspects of cellular reactions during the past decade. In the preface to the first edition we admitted to be newcomers in the field. One of us (JV) has had 10 more years of job training in biotechnology, and the younger author (IN) has now received international recognition for his work with the hottest topics of "modem" biotechnology. Furthermore we are happy to have induced Gunnar Liden, professor of chemical reaction engineering at our sister university in Lund, Sweden to join us as co-author of the second edition. His contribution, especially on the chemical engineering aspects of "real" bioreactors has been of the greatest value. Chapter 8 of the present edition is largely unchanged from the first edition. We wish to thank professor Martin Hjortso from LSU for his substantial help with this chapter.