Download or read book Effect of Blade Planform Variation on a Small Scale Hovering Rotor written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A hover test was conducted on a small-scale rotor model for three sets of tapered rotor blades and a baseline rectangular planform rotor blade. All configurations had the same airfoils, twist, and thrust-weighted solidity. The tapered blade planforms had taper initiating at 50, 75, and 94 percent of the blade radius with a taper ratio of 3 to 1 for each blade set. The experiment was conducted for a range of thrust coefficients, and the data were compared to the predictions of three hover analysis methods. The data show the 94 percent tapered blade was slightly more efficient at the higher rotor thrust levels. The other tapered planform rotors did not show the expected improvement over the baseline rotor, and all configurations had similar performance for low thrust coefficients. None of the analysis methods correlated well with the experimental data. Althoff, Susan L. and Noonan, Kevin W. Langley Research Center DA PROJ. 1L1-61102-AH-45-A; RTOP 505-61-51-10...

Download or read book Effect of Blade Planform Variation on a Small scale Hovering Rotor written by Susan L. Althoff and published by . This book was released on 1990 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Blade Planform Variation on a Small scale Hovering Rotor written by Susan L. Althoff and published by . This book was released on 1990 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Blade Planform Variation on the Forward flight Performance of Small scale Rotors written by and published by . This book was released on 1992 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Blade Planform Variation on the Forward flight Performance of Small scale Rotors written by Kevin W. Noonan and published by . This book was released on 1992 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Blade Planform Variation on the Forward Flight Performance of Small Scale Rotors written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted in the Glenn L. Martin Wind Tunnel to determine the effect of blade planform variation on the forward-flight performance of four small-scale rotors. The rotors were 5.417 ft in diameter and differed only in blade planform geometry. The four planforms were: (1) rectangular; (2) 3:1 linear taper starting at 94 percent radius; (3) 3:1 linear taper starting at 75 percent radius; and (4) 3:1 linear taper starting at 50 percent radius. Each planform had a thrust-weighted solidity of 0.098. The investigation included forward-flight simulation at advance ratios from 0.14 to 0.43 for a range of rotor lift and drag coefficients. Among the four rotors, the rectangular rotor required the highest torque for the entire range of rotor drag coefficients attained at advanced ratios greater than 0.14 for rotor lift coefficients C sub L from 0.004 to 0.007. Among the rotors with tapered blades and for C sub L = 0.004 to 0.007, either the 75 percent tapered rotor or the 50 percent tapered rotor required the least amount of torque for the full range of rotor drag coefficients attained at each advance ratio. The performance of the 94 percent tapered rotor was generally between that of the rectangular rotor and the 75 and 50 percent tapered rotors at each advance ratio for this range of rotor lift coefficients. Noonan, Kevin W. and Althoff, Susan L. and Samak, Dhananjay K. and Green, Michael D. Langley Research Center...

Download or read book Effect of Blade Planform Variation on the Forward Flight Performance of Smal L Scale Rotors written by and published by . This book was released on 1992 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted in the Glenn-L. Martin Wind Tunnel to determine the effects of blade planform variation on the forward-flight flight performance of four small-scale rotors. The rotors were 5.417 ft in diameter and differed only in blade planform geometry. The four planforms were (1) rectangular, (2) 3:l linear taper starting at 94 percent radius, (3) 3:1 linear taper starting at 75 percent radius, and (4) 3:1 linear taper starting at 50 percent radius. Each planform had a thrust-weighted solidity of 0. 098. The investigation included forward-flight simulation at advance ratios from 0.14 to 0.43 for a range of rotor lift and drag coefficients. Among the four rotors, the rectangular rotor required the highest torque for the entire range of rotor drag coefficients attained at advance ratios greater than 0.14 for rotor lift coefficients CL from 0.004 to 0.007. Among the rotors with tapered blades and for CL = 0.004 to 0.007, either the 75-percent tapered rotor or the 50-percent tapered rotor required the least amount of torque for the full range of rotor drag coefficients attained at each advance ratio. The performance of the 94- percent tapered rotor was generally between that of the rectangular rotor and the 75- and 50-percent tapered rotors at each advance ratio for this range of rotor lift coefficients.

Download or read book Effects of Planform Geometry on Hover Performance of a 2 Meter Diameter Model of a Four Bladed Rotor written by Arthur E. Phelps and published by . This book was released on 1986 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hover tests were conducted on three small-scale rotors to evaluate the effect of blade planform taper on rotor hover performance. Tests were conducted on a rectangular swept-tip configuration, on a configuration with a 3-to-1 taper over the outboard 20 percent of the span, and on a configuration with a 5-to-1 taper over the outboard 20 percent of the blade span. The investigation covered a range of thrust coefficients from 0 to 0.0075 and a range of tip speeds from 300 to 600 ft/sec. The test showed that both tapered configurations had better performance than the swept-tip rectangular configuration and that the 3-to-1 taper configuration was better than the 5-to-1 taper configuration. The test results were compared with predictions made with a prescribed-wake analysis, a momentum analysis, and a simplified free-wake analysis. Keywords: Helicopter rotor blades; Rotor hover performance, and Tapered rotor blades.

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1990-11 with total page 1432 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 with total page 1224 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 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1992 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Principles of Helicopter Aerodynamics written by J. Gordon Leishman and published by Cambridge University Press. This book was released on 2002-12-23 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helicopters are highly capable and useful rotating-wing aircraft with roles that encompass a variety of civilian and military applications. Their usefulness lies in their unique ability to take off and land vertically, to hover stationary relative to the ground, and to fly forward, backward, or sideways. These unique flying qualities, however, come at a high cost including complex aerodynamic problems, significant vibrations, high levels of noise, and relatively large power requirements compared to fixed-wing aircraft. This book, written by an internationally recognized expert, provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft. Every chapter is extensively illustrated and concludes with a bibliography and homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thorough and up-to-date text on rotating-wing aerodynamics.

Download or read book Principles of Helicopter Aerodynamics with CD Extra written by Gordon J. Leishman and published by Cambridge University Press. This book was released on 2006-04-24 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by an internationally recognized teacher and researcher, this book provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft such as tilt rotors and autogiros. The text begins with a unique technical history of helicopter flight, and then covers basic methods of rotor aerodynamic analysis, and related issues associated with the performance of the helicopter and its aerodynamic design. It goes on to cover more advanced topics in helicopter aerodynamics, including airfoil flows, unsteady aerodynamics, dynamic stall, and rotor wakes, and rotor-airframe aerodynamic interactions, with final chapters on autogiros and advanced methods of helicopter aerodynamic analysis. Extensively illustrated throughout, each chapter includes a set of homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thoroughly revised and updated text on rotating-wing aerodynamics.

Download or read book Flapping Inertia for Selected Rotor Blades written by John D. Berry and published by . This book was released on 1991 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering written by and published by . This book was released on 1993 with total page 712 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 Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 2001 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: