A Comparison of Plane Turbulent Wakes by Digital Image Analysis Techniques PDF Download

Author: Dennis Frank Visentin
Publisher:
ISBN:
Category :
Languages : en
Pages : 156

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Author: Wade H. Shafer
Publisher: Springer Science & Business Media
ISBN: 1461573882
Category : Science
Languages : en
Pages : 414

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Masters Theses in the Pure and Applied Sciences was first conceived, published, SIld disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna and broader dissemination. tional publishing house to assure improved service Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 30 (thesis year 1985) a total of 12,400 theses titles from 26 Canadian and 186 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work.

Author: A.S. Ginevsky
Publisher: Springer Science & Business Media
ISBN: 3642017606
Category : Mathematics
Languages : en
Pages : 166

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Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309113792
Category : Science
Languages : en
Pages : 102

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Without major changes, the current air transportation system will be unable to accommodate the expected increase in demand by 2025. One proposal to address this problem is to use the Global Positioning System to enable aircraft to fly more closely spaced. This approach, however, might be limited by the wake turbulence problem, which can be a safety hazard when smaller aircraft follow relatively larger aircraft too closely. To examine how this potential hazard might be reduced, Congress in 2005 directed NASA to request a study from the NRC to assess the federal wake turbulence R&D program. This book provides a description of the problem, an assessment of the organizational challenges to addressing wake turbulence, an analysis of the technical challenges in wake turbulence, and a proposal for a wake turbulence program plan. A series of recommendations for addressing the wake turbulence challenge are also given.

Author:
Publisher:
ISBN:
Category : Fluid mechanics
Languages : en
Pages : 544

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Author: Gregory Alan Kopp
Publisher: National Library of Canada = Bibliothèque nationale du Canada
ISBN: 9780612027848
Category :
Languages : en
Pages : 484

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Author: John Olsen
Publisher: Springer Science & Business Media
ISBN: 1468483463
Category : Technology & Engineering
Languages : en
Pages : 599

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The combination of increasing airport congestion and the ad vent of large transports has caused increased interest in aircraft wake turbulence. A quantitative understanding of the interaction between an aircraft and the vortex wake of a preceding aircraft is necessary for planning future high density air traffic patterns and control systems. The nature of the interaction depends on both the characteristics of the following aircraft and the characteristics of the wake. Some of the questions to be answered are: What deter mines the full characteristics of the vortex wake? What properties of the following aircraft are important? What is the role of pilot response? How are the wake characteristics related to the genera ting aircraft parameters? How does the wake disintegrate and where? Many of these questions were addressed at this first Aircraft Wake Turbulence Symposium sponsored by the Air Force Office of Sci entific Research and The Boeing Company. Workers engaged in aero dynamic research, airport operations, and instrument development came from several count ries to present their results and exchange information. The new results from the meeting provide a current picture of the state of the knowledge on vortex wakes and their interactions with other aircraft. Phenomena previously regarded as mere curiosities have emerged as important tools for understanding or controlling vortex wakes. The new types of instability occurring within the wake may one day be used for promoting early dis integration of the hazardous twin vortex structure.

Author: Eduard Naudascher
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 56

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The development of any inhomogeneous free-turbulence flow in an incompressible fluid is predicted through the use of a general self-preservation hypothesis. The analytical solutions are verified by comparison with experimental data on mean-flow and turbulence characteristics of plane and axisymmetric jets in coaxial parallel flow with and without confinement, of an axisymmetric jet in a cross flow, and of the wake behind a self-propelled body. Emphasis is placed on the distinct turbulence structure of the various flows as revealed by the different axial variations of a shear parameter relating turbulence shear to mean velocity. The satisfactory predictions obtained by the new approach make it appear to have a more general application (e.g., to plumes and wall jets) than the examples chosen might imply. (Author).

Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 568

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Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 488

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.