Download or read book Flow Field Analysis of Highly twisted Rotors in Hover written by Gloria Kazuko Yamauchi and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theoretical Analysis of a Hovering Rotor Induced Potential Flow Field written by James Chen-yuan Wu and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flowfield Analysis of Modern Helicopter Rotors in Hover by Navier Stokes Method written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The viscous, three-dimensional, flowfields of UH60 and BERP rotors are calculated for lifting hover configurations using a Navier-Stokes computational fluid dynamics method with a view to understand the importance of planform effects on the airloads. In this method, the induced effects of the wake, including the interaction of tip vortices with successive blades, are captured as a part of the overall flowfield solution without prescribing any wake models. Numerical results in the form of surface pressures, hover performance parameters, surface skin friction and tip vortex patterns, and vortex wake trajectory are presented at two thrust conditions for UH60 and BERP rotors. Comparison of results for the UH60 model rotor show good agreement with experiments at moderate thrust conditions. Comparison of results with equivalent rectangular UH60 blade and BERP blade indicates that the BERP blade, with an unconventional planform, gives more thrust at the cost of more power and a reduced Figure of Merit. The high thrust conditions considered produce severe shock-induced flow separation for UH60 blade, while the BERP blade develops more thrust and minimal separation. The BERP blade produces a tighter tip vortex structure compared with the UH60 blade. These results and the discussion presented bring out the similarities and differences between the two rotors.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Verti flite written by and published by . This book was released on 1996 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rotorcraft Aeromechanics written by Wayne Johnson and published by Cambridge University Press. This book was released on 2013-04-29 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rotorcraft is a class of aircraft that uses large-diameter rotating wings to accomplish efficient vertical take-off and landing. The class encompasses helicopters of numerous configurations (single main rotor and tail rotor, tandem rotors, coaxial rotors), tilting proprotor aircraft, compound helicopters, and many other innovative configuration concepts. Aeromechanics covers much of what the rotorcraft engineer needs: performance, loads, vibration, stability, flight dynamics, and noise. These topics include many of the key performance attributes and the often-encountered problems in rotorcraft designs. This comprehensive book presents, in depth, what engineers need to know about modelling rotorcraft aeromechanics. The focus is on analysis, and calculated results are presented to illustrate analysis characteristics and rotor behaviour. The first third of the book is an introduction to rotorcraft aerodynamics, blade motion, and performance. The remainder of the book covers advanced topics in rotary wing aerodynamics and dynamics.

Download or read book Optimum Performance and Potential Flow Field of Hovering Rotors written by J. C. Wu and published by . This book was released on 1975 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow Field Around a Hovering Rotor written by and published by . This book was released on 1997 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1977 with total page 918 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 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Evaluation of Linearized Vortex Theory as Applied to Single and Multiple Rotors Hovering in and Out of Ground Effect written by Harry H. Heyson and published by . This book was released on 1959 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book PIV Flow Field Measurements of Hovering Rotors with Leading Edge Protuberances written by Brian P. Cully and published by . This book was released on 2017 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability of a helicopter to hover and takeoff/land vertically makes it uniquely suited for many different missions. However, its relatively low forward flight speed has led to a focus on developing helicopters with significantly higher velocity ceilings. The inspiration for the use of protuberances stems from the leading-edge of the pectoral flipper on the humpback whale which, despite its large size, has exceptional maneuverability (i.e., small turning radius) among other whale species. This project utilized thrust and torque measurements and high-resolution particle image velocimetry (PIV) measurements to analyze performance and wake characteristics of rotors with leading-edge protuberances. Four modified blades, with sinusoidal leading-edges of various amplitudes and wavelengths, were compared to a fifth baseline design. As thrust increased, the modified blades required additional power compared to the baseline; this power increase was directly related to protuberance amplitude, while wavelength had a minimal effect. The baseline and low amplitude blades produced similar flow fields: a concentrated tip vortex and a less turbulent wake sheet. Conversely, the higher amplitude blades produced a significantly more turbulent wake sheet and less coherent tip vortices that dissipated quickly. The higher amplitude blades created more uniform (and more ideal) inflow across the rotor disk, but the generation of vortices along these blades most likely contributed to their greater power requirements.

Download or read book Three dimensional Transonic Rotor Flow Field Reconstructed from Holographic Interferogram Data written by J. K. Kittleson and published by . This book was released on 1985 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Holographic interferometry and computer-assisted tomography (CAT) are used to determine the transonic flow field of a model rotor blade in hover. A pulsed ruby laser recorded 40 interferograms with a 61 cm-diam view field near the model rotor-blade tip operating at a tipo Mach number of 0.90. After digitizing the interferograms and extracting fringe-order functions, the data are transferred to a CAT code. The CAT code then calculates pressure coefficients in several planes above the blade surface. The values from the holography-CAT method compare favorably with previously obtained numerical computations and laser velocimeter measurements at most locations near the blade tip. The results demonstrate the techniques's potential for three-dimensional transonic rotor flow studies. Keywords: Holographic interferometry; Computer assisted tomography; Helicopter aerodynamics; Transonic aerodynamics.

Download or read book Laminar Flow Analysis of a Rotor in Hover written by R. Ganesh Rajagopalan and published by . This book was released on 1989 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications Cumulative Index written by United States. Superintendent of Documents and published by . This book was released on 1976 with total page 1466 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fixed and Flapping Wing Aerodynamics for Micro Air Vehicle Applications written by Thomas J. Mueller and published by AIAA. This book was released on 2001 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title reports on the latest research in the area of aerodynamic efficency of various fixed-wing, flapping wing, and rotary wing concepts. It presents the progress made by over fifty active researchers in the field.