Download or read book Flow Visualization of the Wake of a Transport Aircraft Model with Lateral control Oscillations written by Frank L. Jordan and published by . This book was released on 1983 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Patterns in the Sky written by James Franklin Campbell and published by . This book was released on 1994 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Flow Visualization Study of the Wake Produced by an Oscillating Wing written by Allen H. Magnuson and published by . This book was released on with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vortex wakes of Aircrafts written by A.S. Ginevsky and published by Springer Science & Business Media. This book was released on 2009-07-07 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Flow Visualization of the Airwake of an Oscillating Generic Ship Model written by John L. Biskaduros and published by . This book was released on 1987 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental flow visualization study was done on an oscillating generic ship model in the Low Speed Wind Tunnel Facility at the Naval Postgraduate School in Monterey, California. The purpose was to visually analyze the flowfield around the model while simulating ship motion in rough seas, with a correspondingly modelled open-ocean atmospheric boundary layer. The two flow visualization techniques utilized were neutral density helium bubbles and a liquid aerosol, each technique providing varying degrees of on-body and off-body analysis. Limited success was achieved with the aerosol, but the helium bubbles produced excellent photographic results and an accurate visualization of the oscillating model's flow field was achieved.

Download or read book Measurement of the Trailing Vortex Systems of Large Transport Aircraft Using Tower Fly by and Flow Visualization Summary Comparison and Application written by and published by . This book was released on 1976 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full-scale flight test investigations have been made of the characteristics, persistence and movement of the trailing vortices generated by propeller and jet transport aircraft. The tests were performed by the National Aviation Facilities Experimental Center (NAFEC), Atlantic City, New Jersey, during the period 1970-1973, using tower fly-by and vortex flow visualization. The results are summarized and comparisons made of the vortices of the Douglas DC10, DC9, and DC7; Boeing 747, 727, and 707; Lockheed C5A, C141, and L1011; and the Convair 880 aircraft. Vortex mathematical models and decay mechanisms are discussed and their effects (upset potential) on encountering aircraft are investigated for possible air traffic control application.

Download or read book Wake Turbulence written by National Research Council and published by National Academies Press. This book was released on 2008-03-27 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Numerical Study on Turbulent Oscillatory Plane Couette Flow written by Wai-Man Ho and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "A Numerical Study on Turbulent Oscillatory Plane Couette Flow" by Wai-man, Ho, 何慧敏, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the thesis entitled A Numerical Study On Turbulent Oscillatory Plane Couette Flow Submitted by Wai-man Ho for the degree of Master of Philosophy at The University of Hong Kong in June 2004 Steady turbulent plane Couette flow can be readily solved by assuming that the classical log-laws hold locally near the walls. In a sharp contrast, no simple analyses are available if the flow becomes unsteady, as in the case when one of the walls oscillates periodically with time in its own plane. Difficulties arise owning to the time-dependent accelerating terms in the Navier-Stokes equations. The oscillatory boundary may lead to a periodic flow reversal and therefore a detachment of the boundary layer from the wall. Therefore the classical theory of wall turbulence no longer applies to the turbulent oscillatory plane Couette flow. The problem is now handled with the computational technique known as direct numerical simulation (DNS). In this study, turbulent structures and passive scalar transport in an oscillatory plane Couette flow at Reynolds number of 5000 are studied numerically by solving the unsteady incompressible Navier-Stokes equations directly. The oscillatory plane Couette flow consists of a working fluid isandwiched between a lower stationary wall and an upper wall that moves with a prescribed velocity of UA =1+ sin(2πft), where the velocity ratio A = 0, 1/4 and 1/2. The calculation is made using a three-dimensional trilinear Galerkin finite element code. Implicit coupling between velocity and pressure is handled by a fractional-step method. The convection and diffusion terms are respectively computed by the third-order accurate Runge Kutta method and the second-order accurate Crank-Nicolson method. In the oscillatory flow, the velocity and its components are significantly influenced under the wall-oscillation. The scalar transport, however, almost exhibits a consistency in the flows. Comparisons are also made of temperature fluctuations, correlation coefficients, shear stress and heat flux. Although there is no symmetry in the oscillatory-flow channel, most of the DNS data still agrees well with the lower part of the steady-flow channel. Finally, the flow visualization further illustrates the mechanism of high-speed fluid and hot streaky structure. ii DOI: 10.5353/th_b2977083 Subjects: Turbulence - Mathematical models Fluid dynamics

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1983 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Monthly Catalogue United States Public Documents written by and published by . This book was released on 1984 with total page 1252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1983 with total page 1178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Information Output of the Langley Research Center written by and published by . This book was released on 1984 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA SP written by and published by . This book was released on 1993 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering 1983 Cumulative Index written by and published by . This book was released on 1984 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: