Download or read book The Effects of Structural Flap Lag and Pitch Lag Coupling on Soft Inplane Hingeless Rotor Stability in Hover written by and published by DIANE Publishing. This book was released on with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Structural Flap Lag and Pitch Lag Coupling on Soft Inplane Hingeless Rotor Stability in Hover written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-16 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 1.62-m-diameter rotor model was tested in hover to examine the effects of structural flap-lag and pitch-lag coupling on isolated rotor blade lead-lag stability. Flap-lag coupling was introduced by inclining the principal axes of the blade structure up to 60 degrees. Pitch-lag coupling was obtained either alone or in combination with flap-lag coupling through the use of skewed flexural hinges. The principal results confirm the predictions of theory, and show that both structural flap-lag and pitch-lag coupling when used separately are beneficial to blade stability. Moreover, when the couplings are combined, the lead-lag damping is significantly greater than it would be if the individual contributions were superimposed. Pitch-flap coupling is shown to have only a minor effect on blade lead-lag damping. Differences between theory and experiment observed at zero blade pitch and flexure angles during the initial testing were determined in a second test to be caused by stand flexibility. Other differences between theory and experiment warrant further investigation. Bousman, William G. Ames Research Center...
Download or read book The Effects of Structural Flap lag and Pitch lag Coupling on Soft Inplane Hingeless Rotor Stability in Hover written by William G. Bousman and published by DIANE Publishing. This book was released on 1990 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1990 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1990 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Techniques for Improving the Stability of Soft Inplane Hingeless Rotors written by Robert A. Ormiston and published by . This book was released on 1974 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flap Lag Stability Data for a Small Scale Isolated Hingeless Rotor in Forward Flight written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: An isolated, hingeless rotor with discrete flap and lead-lag flexures and relatively rigid blades was tested in the Aeroflightdynamics Directorate's 7- by 10-Foot Wind Tunnel. The lead-lag stability of a structurally simple rotor configuration in forward flight was determined. The model tested had no cyclic pitch control, and was therefore operated untrimmed at several collective pitch angles, at shaft angles from 0 deg to -20 deg, and at advance ratios as high as 0.55. Two inplane natural frequencies, 0.61/rev and 0.72/rev, were tested for configuration both with and without structural flap lag coupling. Concomitant hover testing of the model was also conducted. Representative plots of the frequency and damping data are presented to show general trends, and complete tabular data and model properties information are included for use in detailed correlation exercises. The most prominent feature of the forward flight data is an abrupt increase in damping with advance ratio at certain high-speed, high shaft-angle conditions, with high flapping loads. The hover data are consistent with previous experimental and theoretical results for hingeless rotors without kinematic couplings. Overall, the data quality is very good and the data are expected to be useful in the development and validation of rotor aeroelastic stability analyses. Mcnulty, Michael J. Ames Research Center AEROELASTICITY; DAMPING; DYNAMIC STABILITY; HORIZONTAL FLIGHT; HOVERING; RIGID ROTORS; ROTARY WINGS; ROTOR DYNAMICS; FLEXING; INERTIA; PITCH (INCLINATION); RESONANCE TESTING; RESONANT FREQUENCIES; ROTOR SPEED; STIFFNESS...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flap lag torsion Dynamics of a Uniform Cantilever Rotor Blade in Hover written by and published by . This book was released on 1977 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicopter Theory written by Wayne Johnson and published by Courier Corporation. This book was released on 2012-03-07 with total page 1122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monumental engineering text covers vertical flight, forward flight, performance, mathematics of rotating systems, rotary wing dynamics and aerodynamics, aeroelasticity, stability and control, stall, noise, and more. 189 illustrations. 1980 edition.
Download or read book Rotorcraft Dynamics 1984 written by and published by . This book was released on 1985 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Investigation of the Flap lag Stability of a Hingeless Rotor with Comparable Levels of Hub and Blade Stiffness in Hovering Flight written by and published by . This book was released on 1976 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 2003 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Developments in the Dynamics of Advanced Rotor Systems written by and published by . This book was released on 1985 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Modern Course in Aeroelasticity written by Earl H. Dowell and published by Springer Nature. This book was released on 2021-10-16 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the sixth edition. It is suitable for one or more courses at the advanced undergraduate level and graduate level to cover the field of aeroelasticity. It is also of value to the research scholar and engineering practitioner who wish to understand the state of the art in the field. This book covers the basics of aeroelasticity or the dynamics of fluid–structure interaction. While the field began in response to the rapid development of aviation, it has now expanded into many branches of engineering and scientific disciplines and treats physical phenomena from aerospace engineering, bioengineering, civil engineering, and mechanical engineering in addition to drawing the attention of mathematicians and physicists. The basic questions addressed are dynamic stability and response of fluid structural systems as revealed by both linear and nonlinear mathematical models and correlation with experiment. The use of scaled models and full-scale experiments and tests play a key role where theory is not considered sufficiently reliable.
Download or read book An Experimental Investigation of the Flap lag torsion Aeroelastic Stability of a Small scale Hingeless Helicopter Rotor in Hover written by David L. Sharpe and published by . This book was released on 1986 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
