Download or read book Detection Tracking and Analysis of Turbulent Spots and Other Coherent Structures in Unsteady Transition written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-16 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition on turbine blades is an important factor in the determination of eventual flow separation and engine performance. The phenomenon is strongly affected by unsteady flow conditions (wake passing). It is likely that some physics of unsteadiness should be included in advanced models, but it is unclear which properties would best embody this information. In this paper, we use a GEAE experimental database in unsteady transition to test some tools of spot identification, tracking and characterization. In this preliminary study, we identify some parameters that appear to be insensitive to wake passing effects, such as convection speed, and others more likely to require unsteady modeling. The main findings are that wavelet duration can be used as a measure of spot size, and that spot energy density is most closely correlated to the wake passing. The energy density is also correlated to spot size, but spot size appears unrelated to the phase angle. Recommendations are made for further study. Lewalle, Jacques and Ashpis, David (Technical Monitor) Glenn Research Center NASA/CR-2000-210694, E-12622, NAS 1.26:210694
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2004-07 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Image Velocimetry written by Markus Raffel and published by Springer Science & Business Media. This book was released on 2007-08-09 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This immensely practical guide to PIV provides a condensed, yet exhaustive guide to most of the information needed for experiments employing the technique. This second edition has updated chapters on the principles and extra information on microscopic, high-speed and three component measurements as well as a description of advanced evaluation techniques. What’s more, the huge increase in the range of possible applications has been taken into account as the chapter describing these applications of the PIV technique has been expanded.
Download or read book Stability and Transition in Shear Flows written by Peter J. Schmid and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed look at some of the more modern issues of hydrodynamic stability, including transient growth, eigenvalue spectra, secondary instability. It presents analytical results and numerical simulations, linear and selected nonlinear stability methods. By including classical results as well as recent developments in the field of hydrodynamic stability and transition, the book can be used as a textbook for an introductory, graduate-level course in stability theory or for a special-topics fluids course. It is equally of value as a reference for researchers in the field of hydrodynamic stability theory or with an interest in recent developments in fluid dynamics. Stability theory has seen a rapid development over the past decade, this book includes such new developments as direct numerical simulations of transition to turbulence and linear analysis based on the initial-value problem.
Download or read book Particle Image Velocimetry written by Ronald J. Adrian and published by Cambridge University Press. This book was released on 2011 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle image velocimetry, or PIV, refers to a class of methods used in experimental fluid mechanics to determine instantaneous fields of the vector velocity by measuring the displacements of numerous fine particles that accurately follow the motion of the fluid. Although the concept of measuring particle displacements is simple in essence, the factors that need to be addressed to design and implement PIV systems that achieve reliable, accurate, and fast measurements and to interpret the results are surprisingly numerous. The aim of this book is to analyze and explain them comprehensively.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.
Download or read book New Approaches and Concepts in Turbulence written by T. Dracos and published by Springer Science & Business Media. This book was released on 1993-09-01 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of a colloquium held in Monte Verità from September 9-13, 1991. Special care has been taken to devote adequate space to the scientific discussions, which claimed about half of the time available. Scientists from all over the world presented their views on the importance of kinematic properties, topology and fractal geometry, and on the dynamic behaviour of turbulent flows. They debated the importance of coherent structures and the possibility to incorporate these in the statistical theory of turbulence, as well as their significance for the reduction of the degrees of freedom and the prospective of dynamical systems and chaos approaches to the problem of turbulence. Also under discussion was the relevance of these new approaches to the study of the instability and the origin of turbulence, and the importance of numerical and physical experiments in improving the understanding of turbulence.
Download or read book Instabilities of Flows and Transition to Turbulence written by Tapan K. Sengupta and published by CRC Press. This book was released on 2012-04-24 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressing classical material as well as new perspectives, Instabilities of Flows and Transition to Turbulence presents a concise, up-to-date treatment of theory and applications of viscous flow instability. It covers materials from classical instability to contemporary research areas including bluff body flow instability, mixed convection flows, and application areas of aerospace and other branches of engineering. Transforms and perturbation techniques are used to link linear instability with receptivity of flows, as developed by the author. The book: Provides complete coverage of transition concepts, including receptivity and flow instability Introduces linear receptivity using bi-lateral Fourier-Laplace transform techniques Presents natural laminar flow (NLF) airfoil analysis and design as a practical application of classical and bypass transition Distinguishes strictly between instability and receptivity, which leads to identification of wall- and free stream-modes Describes energy-based receptivity theory for the description of bypass transitions Instabilities of Flows and Transition to Turbulence has evolved into an account of the personal research interests of the author over the years. A conscious effort has been made to keep the treatment at an elementary level requiring rudimentary knowledge of calculus, the Fourier-Laplace transform, and complex analysis. The book is equally amenable to undergraduate students, as well as researchers in the field.
Download or read book Turbulence in Open Channel Flows written by Hiroji Nakagawa and published by Routledge. This book was released on 2017-10-02 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of open channel turbulence, focusing especially on certain features stemming from the presence of the free surface and the bed of a river. Part one presents the statistical theory of turbulence; Part two addresses the coherent structures in open-channel flows and boundary layers.
Download or read book Self sustaining Mechanisms of Wall Turbulence written by Ronald Lee Panton and published by Computational Mechanics. This book was released on 1997 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why is wall turbulence self-sustaining? In this book well-regarded researchers not only discuss what they know and believe, but also speculate on ideas that still require numerical or experimental testing and verification. An initial brief history of boundary layer structure research is followed by chapters on experimental information and specific topics within the subject. There are then sections on computational aspects.
Download or read book Engineering Turbulence Modelling and Experiments 4 written by D. Laurence and published by Elsevier. This book was released on 1999-04-14 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings contain the papers presented at the 4th International Symposium on Engineering Turbulence Modelling and Measurements held at Ajaccio, Corsica, France from 24-26 May 1999. It follows three previous conferences on the topic of engineering turbulence modelling and measurements. The purpose of this series of symposia is to provide a forum for presenting and discussing new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. Turbulence is still one of the key issues in tackling engineering flow problems. As powerful computers and accurate numerical methods are now available for solving the flow equations, and since engineering applications nearly always involve turbulence effects, the reliability of CFD analysis depends more and more on the performance of the turbulence models. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation.
Download or read book Peterson s Annual Guides to Graduate Study written by and published by . This book was released on 1982-12 with total page 996 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Flow Phenomena written by Paolo Orlandi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the simulation of the incompressible Navier-Stokes equations for laminar and turbulent flows. The book is limited to explaining and employing the finite difference method. It furnishes a large number of source codes which permit to play with the Navier-Stokes equations and to understand the complex physics related to fluid mechanics. Numerical simulations are useful tools to understand the complexity of the flows, which often is difficult to derive from laboratory experiments. This book, then, can be very useful to scholars doing laboratory experiments, since they often do not have extra time to study the large variety of numerical methods; furthermore they cannot spend more time in transferring one of the methods into a computer language. By means of numerical simulations, for example, insights into the vorticity field can be obtained which are difficult to obtain by measurements. This book can be used by graduate as well as undergraduate students while reading books on theoretical fluid mechanics; it teaches how to simulate the dynamics of flow fields on personal computers. This will provide a better way of understanding the theory. Two chapters on Large Eddy Simulations have been included, since this is a methodology that in the near future will allow more universal turbulence models for practical applications. The direct simulation of the Navier-Stokes equations (DNS) is simple by finite-differences, that are satisfactory to reproduce the dynamics of turbulent flows. A large part of the book is devoted to the study of homogeneous and wall turbulent flows. In the second chapter the elementary concept of finite difference is given to solve parabolic and elliptical partial differential equations. In successive chapters the 1D, 2D, and 3D Navier-Stokes equations are solved in Cartesian and cylindrical coordinates. Finally, Large Eddy Simulations are performed to check the importance of the subgrid scale models. Results for turbulent and laminar flows are discussed, with particular emphasis on vortex dynamics. This volume will be of interest to graduate students and researchers wanting to compare experiments and numerical simulations, and to workers in the mechanical and aeronautic industries.
Download or read book Instabilities and Turbulence in Engineering Flows written by D. Ashpis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains contributions by colleagues, former students and friends of Professor Eli Reshotko in celebration of his 60th birth day. Since Professor Reshotko's scientific and engineering contribu tions have been in the areas of hydrodynamic stability, transition to turbulence, and boundary layer flows, it is only appropriate that the articles in this volume be devoted to these and related topics. The first two sections focus on instabilities and transition in sub sonic and supersonic flows, respectively. The third section deals with developing turbulence, while the the final section treats related prob lems in engineering fluid mechanics. The diversity and scope of the articles contained herein exemplify the insight and expertise required in the study of transitional and turbulent flows today - traits which also exemplify Eli Reshotko's contributions to these fields. A few of the articles in this volume were presented at a sym posium in honor of Eli Reshotko's 60th birthday, held in Newport News, Virginia, on July 28, 1991. The symposium was sponsored by lCASE, and organized by M.Y. Hussaini (lCASE) and R. Hirsh (U.S. National Science Foundation). Of those who could not attend, many chose to honor Professor Reshotko by a contribution to the volume dedicated to him. We would like to use this opportunity to express our deep ap preciation to M.Y. Hussaini for initiating this very special tribute to Eli, and to Ms. Emily Todd for her efforts in the volume preparation and in the organization of the symposium.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1988 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Turbulence VII written by Uriel Frisch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Turbulence VII contains an overview of the state of turbulence research with some bias towards work done in Europe. It represents an almost complete collection of the invited and contributed papers delivered at the Seventh European Turbulence Conference, sponsored by EUROMECH and ERCOFTAC and organized by the Observatoire de la Côte d'Azur. New high-Reynolds number experiments combined with new techniques of imaging, non-intrusive probing, processing and simulation provide high-quality data which put significant constraints on possible theories. For the first time, it has been shown, for a class of passive scalar problems, why dimensional analysis sometimes gives the wrong answers and how anomalous intermittency corrections can be calculated from first principles. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference as well as anybody interested in this rapidly moving field.
