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Unsteady

Autor: Peyton Corinne

Número de Páginas: 481

«Imposible parar e imposible olvidarlo». BAL KHABRA, autora de Collide UN JUGADOR DE HOCKEY INCAPAZ DE PATINAR Rhys Koteskiy ha vuelto, o al menos, así debería ser. Tras recibir un golpe brutal en el Frozen Four del año pasado, el capitán de hockey de la Universidad Waterfell y promesa de la NHL ya no se siente cómodo en el hielo. Plagado de ataques de pánico cada vez que intenta patinar, Rhys se pregunta si alguna vez podrá volver a jugar o si querrá hacerlo. UNA PATINADORA DECIDIDA A NO SUCUMBIR A LA PRESIÓN Sadie Brown lleva el peso del mundo sobre sus hombros. Con una montaña de deudas, la lucha por la custodia de sus hermanos pequeños, el trabajo, los entrenamientos y la presión para mantener su beca, tiene que centrarse en el patinaje y en sobrevivir al día a día. UNA PRETEMPORADA QUE LO CAMBIARÁ TODO Una mañana, Sadie es testigo de una de las crisis de Rhys. Entonces surge entre ellos una suerte de acuerdo para compartir la pista en secreto. Para el jugador, ella es un tornado de emociones que alivia el vacío que siente, algo fascinante avivado por la creciente atracción que la patinadora se resiste a reconocer. Pero en los sentimientos, como en el...

Turbomachine Unsteady Aerodynamics

Autor: J. S. Rao

Número de Páginas: 542

Unsteady Aerodynamics and Aeroelasticity of Turbomachines

Autor: Torsten H. Fransson

Número de Páginas: 835

Twenty-one years have passed since the first symposium in this series was held in Paris (1976). Since then there have been meetings in Lausanne (1980), Cambridge (1984), Aachen (1987), Beijing (1989), Notre Dame (1991) and Fukuoka (1994). During this period a tremendous development in the field of unsteady aerodynamics and aeroelasticity in turbomachines has taken place. As steady-state flow conditions become better known, and as blades in the turbomachine are constantly pushed towards lower weight, and higher load and efficiency, the importance of unsteady phenomena appear more clearly. th The 8 Symposium was, as the previous ones, of high quality. Furthermore, it presented the audience with the latest developments in experimental, numerical and theoretical research. More papers than ever before were submitted to the conference. As the organising committee wanted to preserve the uniqueness of the symposium by having single sessions, and thus mingle speakers and audience with different backgrounds in this interdisciplinary field, only a limited number of papers could be accepted. 54 papers were accepted and presented at the meeting, all of which are included in the present...

Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines and Propellers

Autor: H.m. Atassi

Número de Páginas: 876

The first International Symposium on Unsteady Aerodynamics and Aero elasticity of Turbomachines was held in Paris in 1976, and was followed by symposia at Lausanne in 1980, Cambridge in 1984, Aachen in 1987, Bei jing in 1989, and Notre Dame in 1991. The proceedings published following these symposia have become recognized both as basic reference texts in the subject area and as useful guides to progress in the field. It is hoped that this volume, which represents the proceedings of the Sixth International Symposium on Unsteady Aerodynamics of Turbomachines, will continue that tradition. Interest in the unsteady aerodynamics, aeroacoustics, and aeroelasticity of turbomachines has been growing rapidly since the Paris symposium. This expanded interest is reflected by a significant increase in the numbers of contributed papers and symposium participants. The timeliness of the topics has always been an essential objective of these symposia. Another important objective is to promote an international exchange between scien tists and engineers from universities, government agencies, and industry on the fascinating phenomena of unsteady turbomachine flows and how they affect the...

Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines

Autor: Kenneth C. Hall , Robert E. Kielb , Jeffrey P. Thomas

Número de Páginas: 648

This textbook is a collection of technical papers that were presented at the 10th International Symposium on Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines held September 8-11, 2003 at Duke University in Durham, North Carolina. The papers represent the latest in state of the art research in the areas of aeroacoustics, aerothermodynamics, computational methods, experimental testing related to flow instabilities, flutter, forced response, multistage, and rotor-stator effects for turbomachinery.

Unsteady Transonic Flow

Autor: Marten T. Landahl

Número de Páginas: 147

This classic monograph on unsteady transonic flow — the flow of air encountered at speeds at or near the speed of sound — is of continuing interest to students and professionals in aerodynamics, fluid dynamics, and other areas of applied mathematics. After a brief Introduction, Swedish physicist Mårten T. Landahl presents a chapter in which the two-dimensional solution is derived, succeeded by a discussion of its relation to the subsonic and supersonic solutions. Three chapters on low aspect ratio configurations follow, covering triangular wings and similar planforms with curved leading edges, rectangular wings, and cropped delta wings, and low aspect ratio wing-body combinations. The treatment concludes with a consideration of the experimental determination of air forces on oscillating wings at transonic speeds.

IUTAM Symposium on Unsteady Separated Flows and their Control

Autor: Marianna Braza , K. Hourigan

Número de Páginas: 588

This Volume is the Proceedings of the IUTAM Symposium on Unsteady Separated Flows and Their Control held in Corfu, Greece, 18–22 June 2007. This was the second IUTAM Symposium on this subject, following the symposium in Toulouse, in April 2002. The Symposium consisted of single plenary sessions with invited lectures, - lected oral presentations, discussions on special topics and posters. The complete set of papers was provided to all participants at the meeting. The thematic sessions of this Symposium are presented in the following: Experimental techniques for the unsteady ow separation Theoretical aspects and analytical approaches of ow separation Instability and transition Compressibility effects related to unsteady separation Statistical and hybrid turbulence modelling for unsteady separated ows Direct and Large-Eddy Simulation of unsteady separated ows Theoretical/industrial aspects of unsteady separated ow control This IUTAM Symposium concerned an important domain of Theoretical and Applied Mechanics nowadays. It focused on the problem of ow separation and of its control. It achieved a uni ed approach regrouping the knowledge provided from theoretical, experimental,...

Unsteady Turbulent Shear Flows

Autor: R. Michel , J. Cousteix , R. Houdeville

Número de Páginas: 445

It was on a proposal from the "Comite National Fran.

Transonic Unsteady Aerodynamics and Aeroelasticity, 1987

Número de Páginas: 684

Calculation of Unsteady Transonic Flows with Mild Separation by Viscous-inviscid Interaction

Autor: James T. Howlett

Número de Páginas: 44

Bibliography and Discussion of Flood-routing Methods and Unsteady Flow in Channels

Autor: Vujica M. Yevjevich

Número de Páginas: 244

Proceedings of the Cambridge Unsteady Flow Symposium 2024

Autor: James C. Tyacke , Nagabhushana Rao Vadlamani

Número de Páginas: 446

This book contains the proceedings of the Cambridge Unsteady Flow Symposium, held on 4–5 March 2024 at the University of Cambridge. The book brings together internationally leading experts in computational fluid dynamics (CFD) and promotes discussions on numerical methods for unsteady flows. The book covers a wide range of topics related to CFD, including but not limited to, large-eddy simulations, unsteady flows in aerospace, high order methods, and mesh generation.

Pseudo-Monotone Operator Theory for Unsteady Problems with Variable Exponents

Autor: Alex Kaltenbach

Número de Páginas: 364

This book provides a comprehensive analysis of the existence of weak solutions of unsteady problems with variable exponents. The central motivation is the weak solvability of the unsteady p(.,.)-Navier–Stokes equations describing the motion of an incompressible electro-rheological fluid. Due to the variable dependence of the power-law index p(.,.) in this system, the classical weak existence analysis based on the pseudo-monotone operator theory in the framework of Bochner–Lebesgue spaces is not applicable. As a substitute for Bochner–Lebesgue spaces, variable Bochner–Lebesgue spaces are introduced and analyzed. In the mathematical framework of this substitute, the theory of pseudo-monotone operators is extended to unsteady problems with variable exponents, leading to the weak solvability of the unsteady p(.,.)-Navier–Stokes equations under general assumptions. Aimed primarily at graduate readers, the book develops the material step-by-step, starting with the basics of PDE theory andnon-linear functional analysis. The concise introductions at the beginning of each chapter, together with illustrative examples, graphics, detailed derivations of all results and a short...

Measurements of Unsteady Turbulent Boundary Layers with Pressure Gradients

Autor: R. L. Simpson , Y.-t. Chew , B. G. Shivaprasad

Número de Páginas: 60

Although periodic unsteady turbulent boundary layers are of real significance in turbomachines and helicopters, little experimental velocity distribution data have been obtained, especially with flow separation. An unsteady turbulent boundary layer facility was developed at SMU to produce almost-sinusoidal waveforms for practical reduced frequencies of the order of unity. Separation occurred on the flat test-wall of the diverging test section. An active boundary layer control system was developed to prevent separation on non-test walls of the test section. Detailed measurements using laser and hot-wire anemometry were made at reduced frequencies of 0.55 and 1.0. Well upstream of separation the flow away from the wall behaved in a quasi-steady manner. Near the wall an unexpected phase shift occurs, which is incompletely explained and may be an instrumentation and apparatus dependent effect.

Computation of Unsteady Internal Flows

Autor: Paul G. Tucker

Número de Páginas: 360

Computation of Unsteady Internal Flows provides an in-depth understanding of unsteady flow modeling and algorithms. This understanding enables suitable algorithms and approaches for particular fields of application to be selected. In addition, the understanding of the behavior of algorithms gained allows practitioners to use them more safely in existing codes, enabling meaningful results to be produced more economically. Features of Computation of Unsteady Internal Flows: Specialized unsteady flow modeling algorithms, their traits, and practical tips relating to their use are presented. Case studies considering complex, practically significant problems are given. Source code and set-up files are included. Intended to be of a tutorial nature, these enable the reader to reproduce and extend case studies and to further explore algorithm performances. Mathematical derivations are used in a fashion that illuminates understanding of the physical implications of different numerical schemes. Physically intuitive mathematical concepts are used. New material on adaptive time stepping is included. £/LIST£ Audience: Researchers in both the academic and industrial areas who wish to gain...

Inclusion of Unsteady Aerodynamics in Longitudinal Parameter Estimation from Flight Data

Autor: M. J. Queijo

Número de Páginas: 62

Unsteady Computational Fluid Dynamics in Aeronautics

Autor: P.g. Tucker

Número de Páginas: 432

The field of Large Eddy Simulation (LES) and hybrids is a vibrant research area. This book runs through all the potential unsteady modelling fidelity ranges, from low-order to LES. The latter is probably the highest fidelity for practical aerospace systems modelling. Cutting edge new frontiers are defined. One example of a pressing environmental concern is noise. For the accurate prediction of this, unsteady modelling is needed. Hence computational aeroacoustics is explored. It is also emerging that there is a critical need for coupled simulations. Hence, this area is also considered and the tensions of utilizing such simulations with the already expensive LES. This work has relevance to the general field of CFD and LES and to a wide variety of non-aerospace aerodynamic systems (e.g. cars, submarines, ships, electronics, buildings). Topics treated include unsteady flow techniques; LES and hybrids; general numerical methods; computational aeroacoustics; computational aeroelasticity; coupled simulations and turbulence and its modelling (LES, RANS, transition, VLES, URANS). The volume concludes by pointing forward to future horizons and in particular the industrial use of LES. The...

Calculated Hydrographs for Unsteady Research Flows at Selected Sites Along the Colorado River Downstream from Glen Canyon Dam, Arizona, 1990 and 1991

Autor: Eleanor R. Griffin , Stephen M. Wiele

Número de Páginas: 40

Fundamentals of Modern Unsteady Aerodynamics

Autor: Ülgen Gülçat

Número de Páginas: 402

In this book, the author introduces the concept of unsteady aerodynamics and its underlying principles. He provides the readers with a comprehensive review of the fundamental physics of free and forced unsteadiness, the terminology and basic equations of aerodynamics ranging from incompressible flow to hypersonics. The book also covers modern topics related to the developments made in recent years, especially in relation to wing flapping for propulsion. The book is written for graduate and senior year undergraduate students in aerodynamics and also serves as a reference for experienced researchers. Each chapter includes ample examples, questions, problems and relevant references. The treatment of these modern topics has been completely revised end expanded for the new edition. It now includes new numerical examples, a section on the ground effect, and state-space representation.

Unsteady Viscous-inviscid Interaction Procedures for Transonic Airfoil Flows

Autor: Tracy Donegan

Número de Páginas: 60

Charts for the Analysis of Isentropic One-dimensional Unsteady Expansions in Equilibrium Real Air with Particular Reference to Shock-initiated Flows

Autor: William L. Grose , Robert L. Trimpi , United States. National Aeronautics And Space Administration

Número de Páginas: 32

Charts are presented which facilitate the theoretical analysis of certain flow processes involving an unsteady expansion wave in equilibrium real air. The parameters evaluated are related to (a) the velocity change in an unsteady expansion wave, (b) the maximum velocity attainable in a shock-wave--expansion-wave cycle, (c) the time for characteristic traversal through an expansion wave, and (d) the entropy in shock-initiated flows. Such parameters are of particular interest in analysis of the shock-initiated expansion-tube cycle.

Numerical Study of Unsteady Viscous Hypersonic Blunt Body Flows with an Impinging Shock

Autor: Goetz H. Klopfer

Número de Páginas: 16

Unsteady Transonic Flow Over Blunt and Pointed Bodies of Revolution

Autor: Hsieh T.

Número de Páginas: 54

Cavity Unsteady-Pressure Measurements at Subsonic and Transonic Speeds

Autor: Maureen B. Tracy

Número de Páginas: 84

Calculation of the Centered One-dimensional Unsteady Expansion of a Reacting Gas Mixture Subject to Vibrational and Chemical Nonequilibrium

Autor: Laurence N. Connor (jr.)

Número de Páginas: 52

Unsteady Aerodynamics

Autor: Grigorios Dimitriadis

Número de Páginas: 581

Unsteady Aerodynamics A comprehensive overview of unsteady aerodynamics and its applications The study of unsteady aerodynamics goes back a century and has only become more significant as aircraft become increasingly sophisticated, fly faster, and their structures are lighter and more flexible. Progress in the understanding of flow physics, computing power and techniques, and modelling technologies has led to corresponding progress in unsteady aerodynamics, with a wide range of methods currently used to predict the performance of engineering structures under unsteady conditions. Unsteady Aerodynamics offers a comprehensive and systematic overview of the application of potential and vortex methods to the subject. Beginning with an introduction to the fundamentals of unsteady flow, it then discusses the modelling of attached and separated, incompressible and compressible flows around two-dimensional and three-dimensional bodies. The result is an essential resource for design and simulation in aerospace engineering. Unsteady Aerodynamics readers will also find: MATLAB examples and exercises throughout, with codes and solutions on an accompanying website Detailed discussion of most...

Unsteady Combustor Physics

Autor: Tim C. Lieuwen

Número de Páginas: 534

Explore a unified treatment of the dynamics of combustor systems, including acoustics, fluid mechanics, and combustion in a single rigorous text. This updated new edition features an expansion of data and experimental material, updates the coverage of flow stability, and enhanced treatment of flame dynamics. Addresses system dynamics of clean energy and propulsion systems used in low emissions systems. Synthesizing the fields of fluid mechanics and combustion into a coherent understanding of the intrinsically unsteady processes in combustors. This is a perfect reference for engineers and researchers in fluid mechanics, combustion, and clean energy.

Unsteady-state Fluid Flow

Autor: E.j. Hoffman

Número de Páginas: 484

The ubiquitous examples of unsteady-state fluid flow pertain to the production or depletion of oil and gas reservoirs. After introductory information about petroleum-bearing formations and fields, reservoirs, and geologic codes, empirical methods for correlating and predicting unsteady-state behavior are presented. This is followed by a more theoretical presentation based on the classical partial differential equations for flow through porous media.Whereas these equations can be simplified for the flow of (compressible) fluids, and idealized solutions exist in terms of Fourier series for linear flow and Bessel functions for radial flow, the flow of compressible gases requires computer solutions, read approximations. An analysis of computer solutions indicates, fortuitously, that the unsteady-state behavior can be reproduced by steady-state density or pressure profiles at successive times. This will demark draw down and the transition to long-term depletion for reservoirs with closed outer boundaries.As an alternative, unsteady-state flow may be presented in terms of volume and surface integrals, and the methodology is fully developed with examples furnished. Among other things,...

Unsteady Viscous Flows

Autor: Demetri P. Telionis

Número de Páginas: 429

Most of the fundamental concepts of unsteady viscous flows have been known since the early part of the century. However, the past decade has seen an unprecedented number of publications in this area. In this monograph I try to connect materials of earlier contributions and synthesize them into a comprehensive entity. One of the main purposes of a monograph, in my opinion, is to fit together in a comprehensive way scattered contributions that provide fragmented information to the readers. The collection of such contributions should be presented in a unified way; continuity of thought and logical sequence of the presentation of ideas and methods are essential. The reader should be able to follow through without having to resort to other references, something that is unavoidable in the case of a research paper or even a review paper. Many of the solutions discussed in the literature address specific practical problems. In fact, in the process of collecting information, I discovered independent lines of investigations, dealing with the same physical problem, but inspired by different practical applications. For example, I found that two groups of investigators have been studying...

Results of astronomical and meteorological observations made at the Radcliffe Observatory, Oxford

Número de Páginas: 236

Results of Astronomical Observations Made at the Radcliffe Observatory, Oxford, in the Year ...

Autor: Radcliffe Observatory

Número de Páginas: 236

Unsteady Aerodynamic Pressures in Transonic Flow

Autor: L. V. Andrew

Número de Páginas: 82

Oscillatory pressures as well as total loads were obtained on a 70-degree delta-wing model undergoing sinusoidal pitch rotation in transonic flow. The mach number range was from 0.8 to 1.2, and the maximum reduced frequency (based on centerline half chord) achieved was 0.172. Corresponding pressures were computer using the kernel function method and the doublet/vortex lattice method at subsonic speeds, the sonic box method, and the supersonic mach box method. Both box methods produce point values of potentials that are fitted by surfaces tyo yeld pressures. Comparisomns of the measured and computer pressures show that, in general (and as expected), the computed pressures are higher than the measured values near the leading edge. Also, in general (but unexpected), the computed phase lags between motion of the surface and the pressures generated by the motion are lower than the measure values.

Results of Meteorological Observations Made ...

Autor: Radcliffe Observatory

Número de Páginas: 436

Results of Astronomical and Meteorological Observations

Autor: Radcliffe Observatory

Número de Páginas: 424

Results of astronomical and meteorological observations made at the Radcliffe Observatory, Oxford

Autor: Radcliffe Observatory

Número de Páginas: 432

Unsteady State Processes in Catalysis

Autor: Yu S. Matros

Número de Páginas: 728

In the last decades the investigation methods of unsteady state catalytic processes have been widely developed by the response-technique methods. From this research emerged the realization that under unsteady state conditions and, especially under artificially created ones, it is possible to increase the productivity or selectivity of a catalyst or a catalytical process as a whole. The scientific literature in this field is mostly theoretical and aims at structuring and analysing mathematical models of unsteady state catalytical processes. In this book the theoretical and applied aspects of an efficiency of artificially created unsteady conditions in catalysis are discussed. It contains the lectures from researchers from all over the world that were held during the International Conference ''Unsteady State Processes in Catalysis'', 5--8 June 1990, Novosibirsk (USSR). Topics include: -- The problems of dynamics of a catalyst surface -- Kinetic models of unsteady processes -- Dynamics of chemical reactors -- Artificially created unsteady processes in a catalytic reactor.

Modeling of longitudinal unsteady aerodynamics of a wingtail combination

Número de Páginas: 29

Application of a Three-dimensional Steady and Unsteady Full Potential Method for Transonic Flow Computations

Autor: J. B. Malone , N. L. Sankar

Número de Páginas: 166

This report describes a study performed to evaluate a 3D, full potential, computational method developed at the Lockheed-Georgia. This computational method was used to compute both steady and unsteady compressible flows about an F-5 fighter wing model. Comparisons are made between computed steady and unsteady aerodynamic data and available experimental data for the F-5 planform. Correlations are presented for steady, unsteady and quasi-steady surface pressure distributions and integrated loads coefficients. Originator-assigned keywords include: Computational fluid dynamics, Unsteady aerodynamics, and Transonic flow.

Results of Astronomical and Meteorological Observations Made at the Radcliffe Observatory, Oxford, in the Year 1871

Número de Páginas: 422

Catalogue of Stars Observed at the U.S. Naval Observatory During the Years 1845-77

Autor: Yarnall

Número de Páginas: 784