Propeller And Rotor Aeroacoustics For Urban Air Mobility Applications

Vortex methods have matured in recent years, offering an interesting alternative to finite difference and spectral methods for high resolution numerical solutions of the Navier Stokes equations. In the past three decades, research into the numerical analysis aspects of vortex methods has provided a solid mathematical background for understanding the accuracy and stability of the method. At the same time vortex methods retain their appealing physical character, which was the motivation for their introduction. This book presents and analyzes vortex methods as a tool for the direct numerical simulation of impressible viscous flows. It will interest graduate students and researchers in numerical analysis and fluid mechanics and also serve as an ideal textbook for courses in fluid dynamics.

The book introduces the fundamentals of fluid-mechanics, momentum theories, vortex theories and vortex methods necessary for the study of rotors aerodynamics and wind-turbines aerodynamics in particular. Rotor theories are presented in a great level of details at the beginning of the book. These theories include: the blade element theory, the Kutta-Joukowski theory, the momentum theory and the blade element momentum method. A part of the book is dedicated to the description and implementation of vortex methods. The remaining of the book focuses on the study of wind turbine aerodynamics using vortex-theory analyses or vortex-methods. Examples of vortex-theory applications are: optimal rotor design, tip-loss corrections, yaw-models and dynamic inflow models. Historical derivations and recent extensions of the models are presented. The cylindrical vortex model is another example of a simple analytical vortex model presented in this book. This model leads to the development of different BEM models and it is also used to provide the analytical velocity field upstream of a turbine or a wind farm under aligned or yawed conditions. Different applications of numerical vortex methods are presented. Numerical methods are used for instance to investigate the influence of a wind turbine on the incoming turbulence. Sheared inflows and aero-elastic simulations are investigated using vortex methods for the first time. Many analytical flows are derived in details: vortex rings, vortex cylinders, Hill's vortex, vortex blobs etc. They are used throughout the book to devise simple rotor models or to validate the implementation of numerical methods. Several Matlab programs are provided to ease some of the most complex implementations.

This book discusses aircraft flight performance, focusing on commercial aircraft but also considering examples of high-performance military aircraft. The framework is a multidisciplinary engineering analysis, fully supported by flight simulation, with software validation at several levels. The book covers topics such as geometrical configurations, configuration aerodynamics and determination of aerodynamic derivatives, weight engineering, propulsion systems (gas turbine engines and propellers), aircraft trim, flight envelopes, mission analysis, trajectory optimisation, aircraft noise, noise trajectories and analysis of environmental performance. A unique feature of this book is the discussion and analysis of the environmental performance of the aircraft, focusing on topics such as aircraft noise and carbon dioxide emissions.

Calculation and optimisation of flight performance is required to design or select new aircraft, efficiently operate existing aircraft, and upgrade aircraft. It provides critical data for aircraft certification, accident investigation, fleet management, flight regulations and safety. This book presents an unrivalled range of advanced flight performance models for both transport and military aircraft, including the unconventional ends of the envelopes. Topics covered include the numerical solution of supersonic acceleration, transient roll, optimal climb of propeller aircraft, propeller performance, long-range flight with en-route stop, fuel planning, zero-gravity flight in the atmosphere, VSTOL operations, ski jump from aircraft carrier, optimal flight paths at subsonic and supersonic speed, range-payload analysis of fixed- and rotary wing aircraft, performance of tandem helicopters, lower-bound noise estimation, sonic boom, and more. This book will be a valuable text for undergraduate and post-graduate level students of aerospace engineering. It will also be an essential reference and resource for practicing aircraft engineers, aircraft operations managers and organizations handling air traffic control, flight and flying regulations, standards, safety, environment, and the complex financial aspects of flying aircraft. Unique coverage of fixed and rotary wing aircraft in a unified manner, including optimisation, emissions control and regulation. Ideal for students, aeronautical engineering capstone projects, and for widespread professional reference in the aerospace industry. Comprehensive coverage of computer-based solution of aerospace engineering problems; the critical analysis of performance data; and case studies from real world engineering experience. Supported by end of chapter exercises

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.

The NACA and aircraft propulsion, 1915-1958 -- NASA gets to work, 1958-1975 -- The shift toward commercial aviation, 1966-1975 -- The quest for propulsive efficiency, 1976-1989 -- Propulsion control enters the computer era, 1976-1998 -- Transiting to a new century, 1990-2008 -- Toward the future