Download or read book Prediction of Aircraft Wake Vortices During Takeoff and Landing written by Grégoire S. Winckelmans and published by [Montréal] : Transportation Development Centre. This book was released on 1999 with total page 73 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 A Flight Evaluation of Methods for Predicting Vortex Wake Effects on Trailing Aircraft written by Glenn H. Robinson and published by . This book was released on 1972 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of four current analytical methods for predicting wing vortex strength and decay rate are compared with the results of a flight investigation of the wake characteristics of several large jet transport aircraft. An empirical expression defining the strength and decay rate of wake vortices is developed that best represents most of the flight-test data. However, the expression is not applicable to small aircraft that would be immersed in the vortex wake of large aircraft.
Download or read book Wake Turbulence written by National Research Council and published by National Academies Press. This book was released on 2008-04-27 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 Aircraft Wake Vortex Spacing System AVOSS Performance Update and Validation Study written by David K. Rutishauser and published by . This book was released on 2001 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis has been performed on data generated from the two most recent field deployments of the Aircraft Wake Vortex Spacing System (AVOSS). The AVOSS provides reduced aircraft spacing criteria for wake vortex avoidance as compared to the FAA spacing applied under Instrument Flight Rules (IFR). Several field deployments culminating in a system demonstration at Dallas Fort Worth (DFW) International Airport in the summer of 2000 were successful in showing a sound operational concept and the system's potential to provide a significant benefit to airport operations. For DFW, a predicted average throughput increase of 6% was observed. This increase implies 6 or 7 more aircraft on the ground in a one-hour period for DFE operations. Several studies of performacne correlations to system configuration options, and system inputs are also reported. The studies focus on the validation performance of the system.
Download or read book Aircraft Wake Vortex Takeoff Tests at O Hare International Airport written by and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Aircraft Wake Vortices Conference Washington D C October 29 31 1991 written by and published by . This book was released on 1992 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer Vortex Forecast System written by S. M. Belotserkovsky and published by [Montréal] : Transportation Development Centre. This book was released on 1999 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of Aircraft Encountering Aircraft Wake Turbulence written by Robert C. Nelson and published by . This book was released on 1974 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The investigation deals with the dynamic behavior of an airplane encountering aircraft wake turbulence. A digital computer simulation was developed to study the response of an aircraft flying into a trailing vortex wake. The simulation includes the complete six degree of freedom equations of motion, a description of the vortex velocity field, unsteady aerodynamics, and pilot control input. The parameters included the penetration angle, separation distance, aircraft size, and pilot control input. Predicted vortex induced motions are presented for general aviation, business, and light jet transport type aircraft.
Download or read book Aircraft Wake Vortices written by T. E. Sullivan and published by . This book was released on 1990 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wake Vortex Avoidance System written by D. J. Wilson and published by . This book was released on 1972 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The requirement for wake vortex avoidance is well established. Encounter of 'heavy' aircraft wake vortices by lighter aircraft trailing by even minutes can be disastrous, especially if the encountering aircraft is flying near the ground in a near-stall condition, i.e., landing or departing. The report provides a conceptual design for a predictive-detective system to: predict the movement and decay of aircraft-generated vortices in air corridors near the air terminal using forecast meteorological conditions, periodically update the prediction by monitoring vortex movements, provide a forecast of separation requirements for optimum aircraft spacing according to prevailing vortex conditions, and provide a waveoff (or hold) capability for rare cases when vortices stray unpredictably into a hazard zone. (Author).
Download or read book Aircraft Wake Vortex Evolution and Prediction written by Frank Holzäpfel and published by . This book was released on 2005 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Predicted Aircraft Wake Vortex Transport and Comparison with Experiment Volume I Wake Vortex Predictive System Study written by M. R. Brashears and published by . This book was released on 1974 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unifying wake vortex transport model is developed and applied to a wake vortex predictive system concept. The fundamentals of vortex motion underlying the predictive model are discussed including vortex decay, bursting and instability phenomena. A parametric and sensitivity analysis is presented to establish baseline uncertainties in the algorithm to allow meaningful comparison of predicted and measured vortex tracks. A detailed comparison of predicted vortex tracks with photographic and groundwind vortex data is presented. Excellent agreement between prediction and measurement is shown to exist when sufficient wind data are available. Application of the Pasquill class criteria is shown to be an effective technique to describe the wind profile in the absence of detailed wind data. The effects of wind shear and the Ekman spiral on vortex transport are discussed. It is shown that the combination of wind shear and ground plane may be possible mechanisms underlying vortex tilting and a theoretical explanation is advanced that is somewhat supported by comparison with the experimental data. Finally, recommendations for further vortex data collection in the vicinity of an airport are presented. (Author).
Download or read book Ask the Pilot written by Patrick Smith and published by Penguin. This book was released on 2004 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Though we routinely take to the air, for many of us flying remains a mystery. Few of us understand the how and why of jetting from New York to London in six hours. How does a plane stay in the air? Can turbulence bring it down? What is windshear? How good are the security checks? Patrick Smith, an airline pilot and author of Salon.com's popular column, "Ask the Pilot," unravels the secrets and tells you all there is to know about the strange and fascinating world of commercial flight. He offers: A nuts and bolts explanation of how planes fly Insights into safety and security Straight talk about turbulence, air traffic control, windshear, and crashes The history, color, and controversy of the world's airlines The awe and oddity of being a pilot The poetry and drama of airplanes, airports, and traveling abroad In a series of frank, often funny explanations and essays, Smith speaks eloquently to our fears and curiosities, incorporating anecdotes, memoir, and a life's passion for flight. He tackles our toughest concerns, debunks conspiracy theories and myths, and in a rarely heard voice dares to return a dash of romance and glamour to air travel.
Download or read book Motion of Aircraft Wake Vortices in Ground Effect written by David C. Burnham and published by Createspace Independent Publishing Platform. This book was released on 2000-04-30 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report addresses the wake-turbulence separation standards for close-spaced parallel runways. Ground-wind anemometer data collected at Kennedy (landing) and O-hare (takeoff) airports are analyzed to assess the lateral transport probability for wake vortices.
Download or read book Numerical Study of Wake Vortex Alleviation written by Hani bin Ludin @ Jamaluddin and published by . This book was released on 2012 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical investigation was undertaken to study the aerodynamic characteristics of wake vortices generated from an aircraft during taking-off or landing, and thus exploring the possible techniques of reducing hazard imposed to the following aircraft by means of passive wake vortex alleviation. An initial study has been carried out on passive wake vortex alleviation by using delta wing (DW) and reverse delta wing (RDW) as an add-on device. Simulations were performed using RANS turbulence model. The results were obtained and quantified at measurement section locations downstream, of x/c=1.359 and x/c=3.418 measured from leading edge point of the model. Comparison between numerical and experimental results has shown good agreement in term of aerodynamic forces for RDW, whereas the comparison is not so good for DW as far as the prediction of drag coefficient is concerned. Although the simulations capture vortex roll-up trends, the size of the vortex is not predicted correctly by RANS turbulence model. Overall, it can be concluded from the results that the wake vortex generated from DW exhibit higher tangential velocity magnitude and circulation than the one generated from RDW at a particular angle of attack (AOA) between 20o to 30o. Subsequently, a broader investigation of another passive wake vortex alleviation technique was performed to study the potential of differential spoiler setting (DSS) of a scaled, half-model aircraft in alleviating the rolling moment induced on the following aircraft. The model was simulated under high lift configuration (HLC) condition, using inherently unsteady technique adopted in LES turbulence model, for two outboard loading cases and two inboard loading cases, in addition to the baseline configuration case. The study has covered near-wake field and extended near-wake field by taking seven measurement section planes at x/b=0.345, x/b=0.444, x/b=0.658, x/b=1.076, x/b=1.794, x/b=2.691 and x/b=4.484. Comparison between numerical simulations and experimental results has shown good agreement in term of lift coefficient for all cases, and fairly acceptable agreement in term of maximum cross-flow velocity, maximum normalized total circulation and maximum induced rolling moment. However, there were some occasions where the comparison is not so good. For instance, the difference error has risen up to 40.3% in term of maximum normalized cross-flow velocity for baseline configuration. Evaluation of the results has showed promising outcomes for the inboard loading cases compared to the outboard loading cases. The interaction between spoilers' wake and outboard flap tip vortex of the inboard loading cases has reduced the tangential velocity magnitude and circulation of the wing tip vortex, and delayed vortex merging to farther distance downstream. This conclusion justifies the DSS's capabilities in wake vortex alleviation. Therefore, DSS can be considered as one of the promising techniques that can be used commercially in the future.
Download or read book Nwra Avoss Wake Vortex Prediction Algorithm 3 1 1 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-03 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides a detailed description of the wake vortex prediction algorithm used in the Demonstration Version of NASA's Aircraft Vortex Spacing System (AVOSS). The report includes all equations used in the algorithm, an explanation of how to run the algorithm, and a discussion of how the source code for the algorithm is organized. Several appendices contain important supplementary information, including suggestions for enhancing the algorithm and results from test cases.Robins, R. E. and Delisi, D. P. and Hinton, David (Technical Monitor)Langley Research CenterALGORITHMS; PREDICTION ANALYSIS TECHNIQUES; WING TIP VORTICES; AIRCRAFT WAKES; AIRCRAFT APPROACH SPACING; COMPUTER PROGRAMS; SOURCE PROGRAMS; ARCHITECTURE (COMPUTERS)
