Download or read book Testing and Evaluation of a Stall flutter suppression System for Helicopter Rotors Using Individual blade control written by Todd Randall Quackenbush and published by . This book was released on 1981 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 26 (thesis year 1981) a total of 11 ,048 theses titles from 24 Canadian and 21 8 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 26 reports theses submitted in 1981, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Download or read book The Design Testing and Evaluation of the MIT Individual blade control System as Applied to Gust Alleviation for Helicopters written by and published by . This book was released on 1980 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Morphing Wing Technologies written by Sergio Ricci and published by Butterworth-Heinemann. This book was released on 2017-10-27 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: Morphing Wings Technologies: Large Commercial Aircraft and Civil Helicopters offers a fresh look at current research on morphing aircraft, including industry design, real manufactured prototypes and certification. This is an invaluable reference for students in the aeronautics and aerospace fields who need an introduction to the morphing discipline, as well as senior professionals seeking exposure to morphing potentialities. Practical applications of morphing devices are presented—from the challenge of conceptual design incorporating both structural and aerodynamic studies, to the most promising and potentially flyable solutions aimed at improving the performance of commercial aircraft and UAVs. Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight. The book consists of eight sections as well as an appendix which contains both updates on main systems evolution (skin, structure, actuator, sensor, and control systems) and a survey on the most significant achievements of integrated systems for large commercial aircraft. - Provides current worldwide status of morphing technologies, the industrial development expectations, and what is already available in terms of flying systems - Offers new perspectives on wing structure design and a new approach to general structural design - Discusses hot topics such as multifunctional materials and auxetic materials - Presents practical applications of morphing devices
Download or read book Investigation of Helicopter Control Loads Induced by Stall Flutter written by P. J. Arcidiacono and published by . This book was released on 1970 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical study was conducted to determine if available unsteady normal force and moment aerodynamic test data could be used in conjunction with existing helicopter rotor aeroelastic and variable inflow analyses to provide a method for predicting the stall flutter response of a helicopter rotor blade. For this purpose, incompressible unsteady aerodynamic data for an NACA 0012 airfoil executing pure sinusoidal pitching motions were employed. To apply such data under rotor blade operating conditions where multiharmonic motions and velocity variations exist, the data were expressed as functions of instantaneous section angle of attack, angular velocity, and angular acceleration. In addition, scaling procedures were developed in an attempt to account for the effects of compressibility. Limited application of the resulting analysis to define the aeroelastic characteristics of several blade designs showed that significant self-excited torsional oscillations of the stall flutter type could, in fact, be predicted for certain combinations of flight conditions and blade designs. Correlation studies, to evaluate the ability of the analysis to predict control loads, were performed with CH-53A maneuvering flight test data and with level flight test data from the NH-3A (S-61F). (Author).
Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 1983 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Suppression of Stall on Helicopter Rotors written by and published by . This book was released on 1999 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the numerical analysis of a stall suppression system for helicopter rotors. The analysis employs a finite element method and includes advanced dynamic stall and vortex wake models. The stall suppression system is based on a transfer function matrix approach and uses blade root actuation to suppress stall directly. The rotor model used in this investigation is the UH-60A rotor. At a severe stalled condition, the analysis predicts three distinct stall events spreading over the retreating side of the rotor disk. Open loop results show that 2P input can reduce stall only moderately, while the other input harmonics are less effective. The responses of the stall index, a measure of stall, to individual input harmonics are highly nonlinear. Such nonlinear stall behavior makes the closed-loop controller ineffective in suppressing stall and the combined effects of individual harmonics nonadditive. Also, stall reduction does not guarantee gains in rotor performance.
Download or read book Aeronautical Engineering written by and published by . This book was released on 1971 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)
Download or read book Technical Information Indexes written by and published by . This book was released on 1975 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book T I S C A Technical Information Indexes written by United States. Naval Air Systems Command and published by . This book was released on 1975 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Stall Flutter of a Helicopter Rotor Blade written by Peter Crimi and published by . This book was released on 1973 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of rotor blade aeroelastic stability was carried out, using an analytic model of a two-dimensional airfoil undergoing dynamic stall and an elastomechanical representation including flapping, flapwise bending and torsional degrees of freedom. Results for a hovering rotor demonstrated that the models used are capable of reproducing both classical and stall flutter. The minimum rotor speed for the occurrence of stall flutter in hover, was found to be determined from coupling between torsion and flapping. Instabilities analogous to both classical and stall flutter were found to occur in forward flight. However, the large stall-related torsional oscillations which commonly limit aircraft forward speed appear to be the response to rapid changes in aerodynamic moment which accompany stall and unstall, rather than the result of an aeroelastic instability. The severity of stall-related instabilities and response was found to depend to some extent on linear stability. Increasing linear stability lessens the susceptibility to stall flutter and reduced the magnitude of the torsional response to stall and unstall.
Download or read book Army Research and Development written by and published by . This book was released on 1973 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Army RD A written by and published by . This book was released on 1974 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Army RD A Bulletin written by and published by . This book was released on 1974 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Helicopter Gust Response Alleviation by Automatic Control written by and published by . This book was released on 1983 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
