Aircraft Drag Reduction Through Extended Formation Flight

Aircraft Drag Reduction Through Extended Formation Flight PDF

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.

Aircraft Drag Reduction Through Extended Formation Flight

Aircraft Drag Reduction Through Extended Formation Flight PDF

Author: Simeon Andrew Ning

Publisher:

Published: 2011

Total Pages:

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.

An Analytical Study of T-38 Drag Reduction in Tight Formation Flight

An Analytical Study of T-38 Drag Reduction in Tight Formation Flight PDF

Author:

Publisher:

Published: 2002

Total Pages: 122

ISBN-13:

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This thesis explores the benefits of flying in a tight formation, mimicking the natural behavior of migratory birds such as geese. The first phase of the research was to determine an optimal position for the wingman of a tight formation flight of T-38 Talon aircraft using the HASC95 vortex lattice code. A second wingman was then added to determine the benefit derived by increasing formation size. The second wingman was predicted to derive an even greater induced drag benefit than the first wingman for T-38s operating at Mach 0.54 at a 10,000-foot altitude. The predicted values were 17.5% savings for the second wingman versus 15% for the first wingman. The flight test phase flew two and three-ship formations to validate the computational work. The results of the two-ship flight tests showed with 80% confidence that the wingman saved fuel in the predicted optimal position (86% wingspan lateral spacing). This position yielded actual fuel savings of 8.8% 5.0% versus the predicted 15%. The other lateral positions did not show a statistically significant fuel savings. The flight test team felt that the three-ship formation data was inconclusive due to the difficulty of trying to fly a stable position as the third aircraft in the formation without station-keeping ability.

An Analytical Study of T-38 Drag Reduction in Tight Formation Flight

An Analytical Study of T-38 Drag Reduction in Tight Formation Flight PDF

Author: Eugene H. Wagner

Publisher:

Published: 2002-03-01

Total Pages: 122

ISBN-13: 9781423512134

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This thesis explores the benefits of flying in a tight formation, mimicking the natural behavior of migratory birds such as geese. The first phase of the research was to determine an optimal position for the wingman of a tight formation flight of T-38 Talon aircraft using the HASC95 vortex lattice code. A second wingman was then added to determine the benefit derived by increasing formation size. The second wingman was predicted to derive an even greater induced drag benefit than the first wingman for T-38s operating at Mach 0.54 at a 10,000-foot altitude. The predicted values were 17.5% savings for the second wingman versus 15% for the first wingman. The flight test phase flew two and three-ship formations to validate the computational work. The results of the two-ship flight tests showed with 80% confidence that the wingman saved fuel in the predicted optimal position (86% wingspan lateral spacing). This position yielded actual fuel savings of 8.8% 5.0% versus the predicted 15%. The other lateral positions did not show a statistically significant fuel savings. The flight test team felt that the three-ship formation data was inconclusive due to the difficulty of trying to fly a stable position as the third aircraft in the formation without station-keeping ability.

Over 40 Publications / Studies Combined: UAS / UAV / Drone Swarm Technology Research

Over 40 Publications / Studies Combined: UAS / UAV / Drone Swarm Technology Research PDF

Author:

Publisher: Jeffrey Frank Jones

Published:

Total Pages: 3840

ISBN-13:

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Over 3,800 total pages ... Just a sample of the studies / publications included: Drone Swarms Terrorist and Insurgent Unmanned Aerial Vehicles: Use, Potentials, and Military Implications Countering A2/AD with Swarming Stunning Swarms: An Airpower Alternative to Collateral Damage Ideal Directed-Energy System To Defeat Small Unmanned Aircraft System Swarms Break the Kill Chain, not the Budget: How to Avoid U.S. Strategic Retrenchment Gyges Effect: An Ethical Critique of Lethal Remotely Piloted Aircraft Human Robotic Swarm Interaction Using an Artificial Physics Approach Swarming UAS II Swarming Unmanned Aircraft Systems Communication Free Robot Swarming UAV Swarm Attack: Protection System Alternatives for Destroyers Confidential and Authenticated Communications in a Large Fixed-Wing UAV Swarm UAV Swarm Behavior Modeling for Early Exposure of Failure Modes Optimized Landing of Autonomous Unmanned Aerial Vehicle Swarms Mini, Micro, and Swarming Unmanned Aerial Vehicles: A Baseline Study UAV Swarm Operational Risk Assessment System SmartSwarms: Distributed UAVs that Think Command and Control Autonomous UxV's UAV Swarm Tactics: An Agent-Based Simulation and Markov Process Analysis A Novel Communications Protocol Using Geographic Routing for Swarming UAVs Performing a Search Mission Accelerating the Kill Chain via Future Unmanned Aircraft Evolution of Control Programs for a Swarm of Autonomous Unmanned Aerial Vehicles AFIT UAV Swarm Mission Planning and Simulation System A Genetic Algorithm for UAV Routing Integrated with a Parallel Swarm Simulation Applying Cooperative Localization to Swarm UAVS Using an Extended Kalman Filter A Secure Group Communication Architecture for a Swarm of Autonomous Unmanned Aerial Vehicles Braving the Swarm: Lowering Anticipated Group Bias in Integrated Fire/Police Units Facing Paramilitary Terrorism Distributed Beamforming in a Swarm UAV Network Integrating UAS Flocking Operations with Formation Drag Reduction Tracking with a Cooperatively Controlled Swarm of GMTI Equipped UAVS Using Agent-Based Modeling to Evaluate UAS Behaviors in a Target-Rich Environment Experimental Analysis of Integration of Tactical Unmanned Aerial Vehicles and Naval Special Warfare Operations Forces Target Acquisition Involving Multiple Unmanned Air Vehicles: Interfaces for Small Unmanned Air Systems (ISUS) Program Tools for the Conceptual Design and Engineering Analysis of Micro Air Vehicles Architectural Considerations for Single Operator Management of Multiple Unmanned Aerial Vehicles

Sustainable Development, International Aviation, and Treaty Implementation

Sustainable Development, International Aviation, and Treaty Implementation PDF

Author: Armand L.C. de Mestral

Publisher: Cambridge University Press

Published: 2018-09-06

Total Pages: 381

ISBN-13: 1107153115

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The international community has succeeded in developing rules to limit greenhouse gas emissions in the atmosphere from international civil aviation. This book examines the development of international law and policy in an area that has remained largely outside the general framework of international environmental law.

Decadal Survey of Civil Aeronautics

Decadal Survey of Civil Aeronautics PDF

Author: National Research Council

Publisher: National Academies Press

Published: 2006-10-27

Total Pages: 212

ISBN-13: 0309101581

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The U.S. air transportation system is very important for our economic well-being and national security. The nation is also the global leader in civil and military aeronautics, a position that needs to be maintained to help assure a strong future for the domestic and international air transportation system. Strong action is needed, however, to ensure that leadership role continues. To that end, the Congress and NASA requested the NRC to undertake a decadal survey of civil aeronautics research and technology (R&T) priorities that would help NASA fulfill its responsibility to preserve U.S. leadership in aeronautics technology. This report presents a set of strategic objectives for the next decade of R&T. It provides a set of high-priority R&T challengesâ€"-characterized by five common themesâ€"-for both NASA and non-NASA researchers, and an analysis of key barriers that must be overcome to reach the strategic objectives. The report also notes the importance of synergies between civil aeronautics R&T objectives and those of national security.

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