Aerodynamic Drag Reduction Technologies
Aerodynamic Drag Reduction Technologies

Author: Peter Thiede

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 382

ISBN-13: 3540453598

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------------------------------------------------------------ This volume contains the Proceedings of the CEAS/DragNet European Drag Reduction Conference held on 19-21 June 2000 in Potsdam, Germany. This conference, succeeding the European Fora on Laminar Flow Technology 1992 and 1996, was initiated by the European Drag Reduction Network (DragNet) and organised by DGLR under the auspice of CEAS. The conference addressed the recent advances in all areas of drag reduction research, development, validation and demonstration including laminar flow technology, adaptive wing concepts, turbulent and induced drag reduction, separation control and supersonic flow aspects. This volume which comprises more than 40 conference papers is of particular interest to engineers, scientists and students working in the aeronautics industry, research establishments or academia.

Aircraft Drag Reduction Through Extended Formation Flight
Aircraft Drag Reduction Through Extended Formation Flight

Author: Simeon Andrew Ning

Publisher: Stanford University

Published: 2011

Total Pages: 146

ISBN-13:

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Formation flight has the potential to significantly reduce the fuel consumption of long range flights, even with existing aircraft. This research explores a safer approach to formation flying of transport aircraft, which we term extended formation flight. Extended formations take advantage of the persistence of cruise wakes and extend the streamwise separation between the aircraft by at least five wingspans. Classical aerodynamic theory suggests that the total induced drag of the formation should not change as the streamwise separation is increased, but the large separation distances of extended formation flight violate the simple assumptions of these theorems. At large distances, considerations such as wake rollup, atmospheric effects on circulation decay, and vortex motion become important to consider. We first examine the wake rollup process in the context of extended formations and develop an appropriate physics-based model. Using this model, this dissertation addresses three aspects of formation flight: longitudinally extended formations, compressibility effects, and formations of heterogeneous aircraft. Uncertainty analysis is used to investigate the induced drag savings of extended formations in the presence of variation in atmospheric properties, limitations of positioning accuracy, and uncertainty in model parameters. Next, the methodology is integrated with an Euler solver to assess the impact of compressibility while flying in formation. Finally, we examine the important considerations for optimally arranging formations of non-identical aircraft.

Drag Reduction: An Industrial Challenge
Drag Reduction: An Industrial Challenge

Author: J. P. Robert

Publisher:

Published: 1992

Total Pages: 15

ISBN-13:

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Over the last few decades and particularly since the 70s, all civil aircraft manufacturers have made great efforts to reduce aircraft drag. The long term aim of this operation is to reduce the specific consumption of aircraft, the potential reduction of over 10 % would represent savings of several million dollars for the airlines (fig. 1). The successive fuel crises (fig. 2) have increased the need for developing new technologies to be applied on the new aircraft; retrofits, however, also have their uses. Estimating the drag of a transport aircraft through calculation or wind tunnel tests must come as close as possible to the value obtained in flight. Forecast errors to the order of 1 % following wind tunnel/flight transposition lead to technical and financial penalties and entail vast efforts to bring the values obtained during flight down to acceptable levels guaranteed by the aircraft manufacturers to their customer airlines. The technologies or concepts that could significantly reduce aircraft drag often have a different reduction potential. This reduction must be clearly shown to appear in the high speed tests using large-scale models (1/10 scale).

Aircraft Drag Reduction: An Overview
Aircraft Drag Reduction: An Overview

Author: Mohsen Jahanmiri

Publisher: LAP Lambert Academic Publishing

Published: 2013-01

Total Pages: 72

ISBN-13: 9783659336423

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Aircraft drag reduction is a great challenge but there is certainly room for improvements. The drag breakdown of a civil transport aircraft shows that the skin friction drag and the lift-induced drag constitute the two main sources of drag, approximately one half and one third of the total drag for a typical long range aircraft at cruise conditions. This is why specific research on this topics have been initiated and it seems that Hybrid Laminar Flow technology and innovative wing tip devices offer the greatest potential. The aim of this review manuscript is to highlight the state of the art in aeronautical drag reduction, and also describe several emerging drag-reduction approaches that are either active or reactive/interactive.

Aerodynamics, Aeronautics, and Flight Mechanics
Aerodynamics, Aeronautics, and Flight Mechanics

Author: Barnes W. McCormick

Publisher: John Wiley & Sons

Published: 1994-09-28

Total Pages: 677

ISBN-13: 0471575062

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A New Edition of the Most Effective Text/Reference in the Field! Aerodynamics, Aeronautics, and Flight Mechanics, Second Edition Barnes W. McCormick, Pennsylvania State University 57506-2 When the first edition of Aerodynamics, Aeronautics, and Flight Mechanics was published, it quickly became one of the most important teaching and reference tools in the field. Not only did generations of students learn from it, they continue to use it on the job-the first edition remains one of the most well-thumbed guides you'll find in an airplane company. Now this classic text/reference is available in a bold new edition. All new material and the interweaving of the computer throughout make the Second Edition even more practical and current than before! A New Edition as Complete and Applied as the First Both analytical and applied in nature, Aerodynamics, Aeronautics, and Flight Mechanics presents all necessary derivations to understand basic principles and then applies this material to specific examples. You'll find complete coverage of the full range of topics, from aerodynamics to propulsion to performance to stability and control. Plus, the new Second Edition boasts the same careful integration of concepts that was an acclaimed feature of the previous edition. For example, Chapters 9, 10, and 11 give a fully integrated presentation of static, dynamic, and automatic stability and control. These three chapters form the basis of a complete course on stability and control. New Features You'll Find in the Second Edition * A new chapter on helicopter and V/STOL aircraft- introduces a phase of aerodynamics not covered in most current texts * Even more material than the previous edition, including coverage of stealth airplanes and delta wings * Extensive use of the computer throughout- each chapter now contains several computer exercises * A computer disk with programs written by the author is available

Introduction to Aircraft Flight Mechanics
Introduction to Aircraft Flight Mechanics

Author: Thomas R. Yechout

Publisher: AIAA

Published: 2003

Total Pages: 666

ISBN-13: 9781600860782

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Based on a 15-year successful approach to teaching aircraft flight mechanics at the US Air Force Academy, this text explains the concepts and derivations of equations for aircraft flight mechanics. It covers aircraft performance, static stability, aircraft dynamics stability and feedback control.

A Design and Analysis Approach for Drag Reduction on Aircraft with Adaptive Lifting Surfaces
A Design and Analysis Approach for Drag Reduction on Aircraft with Adaptive Lifting Surfaces

Author:

Publisher:

Published: 2004

Total Pages:

ISBN-13:

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Adaptive lifting surfaces, which can be tailored for different flight conditions, have been shown to be beneficial for drag reduction when compared with conventional non-adaptive surfaces. Applying multiple trailing-edge flaps along the wing span allows for the redistribution of lift to suit different flight conditions. The current approach uses the trailing-edge flap distribution to reduce both induced- and profile- components of drag with a trim constraint. Induced drag is reduced by optimally redistributing the lift between the lifting surfaces and along the span of each surface. Profile drag is reduced through the use of natural laminar flow airfoils, which maintain distinct low-drag-ranges (drag buckets) surrounding design lift values. The low-drag-ranges can be extended to include off-design values through small flap deflections, similar to cruise flaps. Trim is constrained for a given static margin by considering longitudinal pitching moment contributions from changes in airfoil section due to individual flap deflections, and from the redistribution of fore-and-aft lift due to combination of flap deflections. The approach uses the concept of basic and additional lift to linearlize the problem, which allows for standard constrained-minimization theory to be employed for determining optimal flap-angle solutions. The resulting expressions for optimal flap-angle solutions are presented as simple matrix equations. This work presents a design and analysis approach which is used to produce flap-angle solutions that independently reduce induced, profile, and total drag. Total drag is defined to be the sum of the induced- and profile-components of drag. The general drag reduction approach is adapted for each specific situation to develop specific drag reduction schemes that are applied to single- and multiple-surface configurations. Successful results show that, for the application of the induced drag reduction schemes on a tailless aircraft, near-elliptical lift dist.