Download or read book Helicopter type Rotor Decelerators written by R. R. Tyndall and published by . This book was released on 1963 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helicoptr-type rotors appear attractive for the deceleration, trajectory control, gliding descent and final recovery of almost all types of aero space payloads. The potential of rotors is based upon (1) their inherent virtues of L/D gliding capability, controllability, and soft, flared landing; (2) past experience with uncontrolled rotor-decelerated air-dropped stores; and (3) helicopters having the capabilities of control, autorotation, and flare-out to land. Aero nautical Systems Division, as well as other Government agencies, believes that rotor decelerators have potential, particularly in light of the desired expansion of limited war capability, and is conducting applied research to explore the basic feasibility of using rotors for aerospace payload recovery. This effort involves both wind tunnel testing in the transonic-super sonic range, and free-flight testing at deployment speeds up to Mach 0.9 and analyses. To date, wind tunnel tests have demonstrated the deployment, operating, and drag characteristics of an eight-foot diameter rotor decelerator through a Mach number range from 0.5 to 1.5. Analyses have indicated that rotors, as well as providing subsonic performance capability, may have potential as hypersonic glide and drag devices. Thus, rotor decelerator potential embraces the spectrum ranging from relatively low-speed aerial delivery of payloads to suborbital and orbital space vehicle recovery. (Author).

Download or read book Smart Helicopter Rotors written by Ranjan Ganguli and published by Springer. This book was released on 2015-12-16 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibration caused by dynamic stall. The exposition of ideas, materials and algorithms in this monograph is supported by extensive reporting of results from numerical simulations of smart helicopter rotors. This monograph will be a valuable source of reference for researchers and engineers with backgrounds in aerospace, mechanical and electrical engineering interested in smart materials and vibration control. Advances in Industrial Control aims to report and encourage the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.

Download or read book Hovering and Low speed Performance and Control Characteristics of an Aerodynamic servocontrolled Helicopter Rotor System as Determined on the Langley Helicopter Tower written by Paul J. Carpenter and published by . This book was released on 1950 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rotor system investigated is a servocontrol type with blades fastened rigidly at the hub and twisted outboard by auxiliary airfoils called flaps to obtain pitch control.

Download or read book A Tabulation of Helicopter Rotor blade Differential Pressures Stresses and Motions as Measured in Flight written by James Scheiman and published by . This book was released on 1964 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Static Stability Measurements of a Stand on Type Helicopter with Rigid Blades Including a Comparison with Theory written by George E. Sweet and published by . This book was released on 1960 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rotor body Aerodynamic Interactions written by Mark D. Betzina and published by . This book was released on 1983 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wind-tunnel investigation was conducted in which independent, steady-state aerodynamic forces and moments were measured on a 2.24-m-diam, two- bladed helicopter rotor and on several different bodies. The objective was to determine the mutual interaction effects for variations in velocity, thrust, tip-path-plane angle of attack, body angle of attack, rotor/body position, and body geometry. the results of the investigation show that the body longitudinal aerodynamic characteristics are significantly affected by the presence of a rotor and hub, and that the hub interference may be a major part of such interaction. This report presents the effects of various parameters on the interactions and discusses the difficulties encountered in determining the effect of the body on the rotor performance.

Download or read book Helicopters written by David Baker and published by . This book was released on 1987 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses helicopter designs, how helicopters fly, and their many military uses.

Download or read book Cyclic and Collective written by Shawn Coyle and published by Lulu.com. This book was released on 2009 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Possibly the most complete book written to date on helicopters and helicopter flying. Covers subjects not covered by other manuals such as turbine engines, performance, flight manuals, automatic flight controls, legal aspects, introductory stability and control and multi-engine helicopters.

Download or read book Helicopter History and Aerodynamics written by United States. Air Force. Air Training Command and published by . This book was released on 1961 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Foundations of Helicopter Flight written by S. Newman and published by Elsevier. This book was released on 1994-04-07 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique design problems which helicopters produce are many and complex. Through practical examples and illustrated case studies, supported by all the relevant theory, this primer text provides an accessible introduction which guides the reader through the theory, design, construction and operation of helicopters. Fundamental performance and control equations are developed, from which the book explores the rotor aerodynamic and dynamic characteristics of helicopters. Example calculations and performance predictions, reflecting current practice, show how to assess the feasibility of a design. * Tackles the theory, design, construction and operation of helicopters* Illustrated with many practical examples and case studies* Provides the fundamental equations describing performance and dynamic behaviour

Download or read book Helicopter Blade Dynamic Loads Measured During Performance Testing of Two Scaled Rotors written by John D. Berry and published by . This book was released on 1987 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rotorcraft Aeromechanical Stability methodology Assessment Phase 2 Workshop written by William Giles Bousman and published by . This book was released on 1990 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Basic Helicopter Handbook written by United States. Flight Standards Service and published by . This book was released on 1978 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Special Opportunities in Helicopter Aerodynamics written by W. J. McCroskey and published by . This book was released on 1983 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic research relating to modern helicopters includes the study of three-dimensional, unsteady, nonlinear flow fields. A selective review is made of some of the phenomenon that hamper the development of satisfactory engineering prediction techniques, but which provides a rich source of research opportunities: flow separations, compressibility effects, complex vortical wakes, and aerodynamic interference between components. Several examples of work in progress are given, including dynamic stall alleviation, the development of computational methods for transonic flow, rotor-wake predictions, and blade-vortex interactions. (Author).

Download or read book The History of the XV 15 Tilt Rotor Research Aircraft written by Martin D. Maisel and published by . This book was released on 2000 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Summary of Rotor hub Bending Moments Encountered by a High performance Hingeless rotor Helicopter During Nap of the earth Maneuvers written by William J. Snyder and published by . This book was released on 1968 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Aerodynamics written by Raymond W. Prouty and published by . This book was released on 1985 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: