Interaction of a Shock with a Longitudinal Vortex

Interaction of a Shock with a Longitudinal Vortex PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781729292655
Category : Science
Languages : en
Pages : 50

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Book Description
In this paper we study the shock/longitudinal vortex interaction problem in axisymmetric geometry. Linearized analysis for small vortex strength is performed, and compared with results from a high order axisymmetric shock-fitted Euler solution obtained for this purpose. It is confirmed that for weak vortices, predictions from linear theory agree well with results from nonlinear numerical simulations at the shock location. To handle very strong longitudinal vortices, which may ultimately break the shock, we use an axisymmetric high order essentially non-oscillatory (ENO) shock capturing scheme. Comparison of shock-captured and shock-fitted results are performed in their regions of common validity. We also study the vortex breakdown as a function of Mach number ranging from 1.3 to 10, thus extending the range of existing results. For vortex strengths above a critical value. a triple point forms on the shock and a secondary shock forms to provide the necessary deceleration so that the fluid velocity can adjust to downstream conditions at the shock. Erlebacher, Gordon and Hussaini, M. Y. and Shu, Chi-Wang Langley Research Center NAS 1-19480; NSF DMS-95-00814; AF-AFSOR-95-1-0074; DAAH-04-94-G-0205; NAG 1-1145; RTOP 505-90-52-01

Interaction of a Shock with a Longitudinal Vortex

Interaction of a Shock with a Longitudinal Vortex PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781729292655
Category : Science
Languages : en
Pages : 50

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Book Description
In this paper we study the shock/longitudinal vortex interaction problem in axisymmetric geometry. Linearized analysis for small vortex strength is performed, and compared with results from a high order axisymmetric shock-fitted Euler solution obtained for this purpose. It is confirmed that for weak vortices, predictions from linear theory agree well with results from nonlinear numerical simulations at the shock location. To handle very strong longitudinal vortices, which may ultimately break the shock, we use an axisymmetric high order essentially non-oscillatory (ENO) shock capturing scheme. Comparison of shock-captured and shock-fitted results are performed in their regions of common validity. We also study the vortex breakdown as a function of Mach number ranging from 1.3 to 10, thus extending the range of existing results. For vortex strengths above a critical value. a triple point forms on the shock and a secondary shock forms to provide the necessary deceleration so that the fluid velocity can adjust to downstream conditions at the shock. Erlebacher, Gordon and Hussaini, M. Y. and Shu, Chi-Wang Langley Research Center NAS 1-19480; NSF DMS-95-00814; AF-AFSOR-95-1-0074; DAAH-04-94-G-0205; NAG 1-1145; RTOP 505-90-52-01

Vortex Dominated Flows

Vortex Dominated Flows PDF Author: Lu Ting
Publisher: World Scientific
ISBN: 9812703438
Category : Science
Languages : en
Pages : 302

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Book Description
Honoring the contributions of one of the field''s leading experts, Lu Ting, this indispensable volume contains important new results at the cutting edge of research. A wide variety of significant new analytical and numerical results in critical areas are presented, including point vortex dynamics, superconductor vortices, cavity flows, vortex breakdown, shock/vortex interaction, wake flows, magneto-hydrodynamics, rotary wake flows, and hypersonic vortex phenomena. The book will be invaluable for those interested in the state of the art of vortex dominated flows, both from a theoretical and applied perspective. Professor Lu Ting and Joe Keller have worked together for over 40 years. In their first joint work entitled OC Periodic vibrations of systems governed by nonlinear partial differential equationsOCO, perturbation analysis and bifurcation theory were used to determine the frequencies and modes of vibration of various physical systems. The novelty was the application to partial differential equations of methods which, previously, had been used almost exclusively on ordinary differential equations. Professsor Lu Ting is an expert in both fluid dynamics and the use of matched asymptotic expansions. His physical insight into fluid flows has led the way to finding the appropriate mathematical simplications used in the solutions to many difficult flow problems."

Vortex Dominated Flows

Vortex Dominated Flows PDF Author: Denis L. Blackmore
Publisher: World Scientific
ISBN: 9812563202
Category : Science
Languages : en
Pages : 299

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Book Description
Honoring the contributions of one of the field's leading experts, Lu Ting, this indispensable volume contains important new results at the cutting edge of research. A wide variety of significant new analytical and numerical results in critical areas are presented, including point vortex dynamics, superconductor vortices, cavity flows, vortex breakdown, shock/vortex interaction, wake flows, magneto-hydrodynamics, rotary wake flows, and hypersonic vortex phenomena.The book will be invaluable for those interested in the state of the art of vortex dominated flows, both from a theoretical and applied perspective.Professor Lu Ting and Joe Keller have worked together for over 40 years. In their first joint work entitled ?Periodic vibrations of systems governed by nonlinear partial differential equations?, perturbation analysis and bifurcation theory were used to determine the frequencies and modes of vibration of various physical systems. The novelty was the application to partial differential equations of methods which, previously, had been used almost exclusively on ordinary differential equations. Professsor Lu Ting is an expert in both fluid dynamics and the use of matched asymptotic expansions. His physical insight into fluid flows has led the way to finding the appropriate mathematical simplications used in the solutions to many difficult flow problems.

Shock Wave-Boundary-Layer Interactions

Shock Wave-Boundary-Layer Interactions PDF Author: Holger Babinsky
Publisher: Cambridge University Press
ISBN: 1139498649
Category : Technology & Engineering
Languages : en
Pages : 481

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Book Description
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.

Key Basic Scientific Problems on Near-Space Vehicles

Key Basic Scientific Problems on Near-Space Vehicles PDF Author: Shanyi Du
Publisher: Springer Nature
ISBN: 9811989079
Category : Technology & Engineering
Languages : en
Pages : 134

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Book Description
This book mainly introduces the research overview, research results, and follow-up prospects of “Key Basic Scientific Problems on Near-Space Vehicles”, a major research plan of National Natural Science Foundation of China (hereinafter referred to as the Plan). The Plan is the first systematic basic hypersonic research program in China. From its inception in 2007 to its successful completion in 2016, the Plan lasted nine years, funded a total of 173 projects, and the funding totaled 190 million yuan. From the perspective of major national needs and scientific discipline development, the book focuses on four key scientific issues: aerodynamics in a near-space flight environment; advanced propulsion theories and methods; ultralight materials/structures, thermal environment prediction and thermal protection; and intelligent autonomous control theories and methods for hypersonic vehicles. The book also demonstrates China’s systematic and innovative achievements in interdisciplinary theories and methods and innovative techniques, paving the way for a distinctively Chinese basic research framework and further breakthroughs of near-space hypersonic vehicles.

Advanced Numerical Approximation of Nonlinear Hyperbolic Equations

Advanced Numerical Approximation of Nonlinear Hyperbolic Equations PDF Author: B. Cockburn
Publisher: Springer
ISBN: 3540498044
Category : Mathematics
Languages : en
Pages : 446

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Book Description
This volume contains the texts of the four series of lectures presented by B.Cockburn, C.Johnson, C.W. Shu and E.Tadmor at a C.I.M.E. Summer School. It is aimed at providing a comprehensive and up-to-date presentation of numerical methods which are nowadays used to solve nonlinear partial differential equations of hyperbolic type, developing shock discontinuities. The most effective methodologies in the framework of finite elements, finite differences, finite volumes spectral methods and kinetic methods, are addressed, in particular high-order shock capturing techniques, discontinuous Galerkin methods, adaptive techniques based upon a-posteriori error analysis.

Liutex and Its Applications in Turbulence Research

Liutex and Its Applications in Turbulence Research PDF Author: Chaoqun Liu
Publisher: Academic Press
ISBN: 0128190248
Category : Technology & Engineering
Languages : en
Pages : 460

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Book Description
Liutex and Its Applications in Turbulence Research reviews the history of vortex definition, provides an accurate mathematical definition of vortices, and explains their applications in flow transition, turbulent flow, flow control, and turbulent flow experiments. The book explains the term "Rortex" as a mathematically defined rigid rotation of fluids or vortex, which could help solve many longstanding problems in turbulence research. The accurate mathematical definition of the vortex is important in a range of industrial contexts, including aerospace, turbine machinery, combustion, and electronic cooling systems, so there are many areas of research that can benefit from the innovations described here. This book provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence. Important theory and methodologies used for developing these laws are described in detail, including: the classification of the conventional turbulent boundary layer concept based on proper velocity scaling; the methodology for identification of the scales of velocity, temperature, and length needed to establish the law; and the discovery, proof, and strict validations of the laws, with both Reynolds and Prandtl number independency properties using DNS data. The establishment of these statistical laws is important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence. - Provides an accurate mathematical definition of vortices - Provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence - Explains the term "Rortex as a mathematically defined rigid rotation of fluids or vortex - Covers the statistical laws important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence

Computational Fluid and Solid Mechanics 2003

Computational Fluid and Solid Mechanics 2003 PDF Author: K.J Bathe
Publisher: Elsevier
ISBN: 008052947X
Category : Technology & Engineering
Languages : en
Pages : 2485

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Book Description
Bringing together the world's leading researchers and practitioners of computational mechanics, these new volumes meet and build on the eight key challenges for research and development in computational mechanics.Researchers have recently identified eight critical research tasks facing the field of computational mechanics. These tasks have come about because it appears possible to reach a new level of mathematical modelling and numerical solution that will lead to a much deeper understanding of nature and to great improvements in engineering design.The eight tasks are: - The automatic solution of mathematical models - Effective numerical schemes for fluid flows - The development of an effective mesh-free numerical solution method - The development of numerical procedures for multiphysics problems - The development of numerical procedures for multiscale problems - The modelling of uncertainties - The analysis of complete life cycles of systems - Education - teaching sound engineering and scientific judgement Readers of Computational Fluid and Solid Mechanics 2003 will be able to apply the combined experience of many of the world's leading researchers to their own research needs. Those in academic environments will gain a better insight into the needs and constraints of the industries they are involved with; those in industry will gain a competitive advantage by gaining insight into the cutting edge research being carried out by colleagues in academia. Features - Bridges the gap between academic researchers and practitioners in industry - Outlines the eight main challenges facing Research and Design in Computational mechanics and offers new insights into the shifting the research agenda - Provides a vision of how strong, basic and exciting education at university can be harmonized with life-long learning to obtain maximum value from the new powerful tools of analysis

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

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Book Description


Research in Progress

Research in Progress PDF Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 1194

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Book Description