Download or read book Wind tunnel Test of an Articulated Helicopter Rotor Model with Several Tip Shapes written by John D. Berry and published by . This book was released on 1980 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wind-tunnel investigation has been conducted using an articulated helicopter model rotor system to determine the effects of several blade tip designs on both the performance and acoustic characteristics of the rotor. Only the performance characteristics are presented in this paper. Six tip shapes were tested: a square (baseline) tip, an ogee tip, a subwing tip, a swept tip, a winglet tip, and a short ogee tip. Tests were conducted at two rotor rotational speeds and five advance ratios including hover. In hover at the lower rotational speed and a given lift coefficient, the swept, ogee, and short ogee tips had about the same torque coefficient, and the subwing and winglet tips had a larger torque coefficient than the baseline square tip blades. In simulated forward flight, the ogee tip had values of torque coefficient very close to or less than the baseline square tip blades. In simulated forward flight at 1200 rpm, the ogee tips showed a decrease in torque coefficient relative to the baseline blades as drag coefficient decreased. The swept tip blades required less torque coefficient at lower rotational speeds than the baseline square tip blades and roughly equivalent torque coefficient at higher rotational speeds in forward flight. The short ogee tip was tested in limited forward flight conditions and it required higher torque coefficient at higher lift coefficient than the baseline square tip blade. (Author).

Download or read book Wind tunnel test of an articulated helicopter rotor model with several tip shapes written by John D. Berry and published by . This book was released on 1980 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Aeroelastic Considerations for Torsionally Soft Rotors written by Wayne R. Mantay and published by . This book was released on 1986 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research study was initiated to systematically determine the impact of selected blade tip geometric parameters on conformable rotor performance and loads characteristics. The model articulated rotors included baseline and torsionally soft blades with interchangeable tips. Seven blade tip designs were evaluated on the baseline rotor and six tip designs were tested on the torsionally soft blades. The designs incorporated a systemmatic variation in geometric parameters including sweep, taper, and anhedral. The rotors were evaluated in the NASA Langley Transonic Dynamics Tunnel at several advance ratios, lift and propulsive force values, and tip Mach numbers. A track sensitivity study was also conducted at several advance ratios for both rotors. Based on the test results, tip parameter variations generated significant rotor performance and loads differences for both baseline and torsionally soft blades. Azimuthal variation of elastic twist generated by variations in the tip parameters strongly correlated with rotor performance and loads, but the magnitude of advancing blade elastic twist did not. In addition, fixed system vibratory loads and rotor track for potential conformable rotor candidates appears very sensitive to parametric rotor changes. (Author).

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1989 with total page 468 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 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 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 Technical Abstract Bulletin written by and published by . This book was released on 1981 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 37th AIAA Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 1999 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1981 with total page 1308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA SP written by and published by . This book was released on 1992 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book R D Abstracts written by Technology Reports Centre (Great Britain) and published by . This book was released on 1981 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1981 with total page 1192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Download or read book 1980 NASA Authorization written by United States. Congress. House. Committee on Science and Technology. Subcommittee on Space Science and Applications and published by . This book was released on 1978 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parametric Tip Effects for Conformable Rotor Applications written by W. R. Mantay and published by . This book was released on 1983 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research study was initiated to systematically determine the impact of selected blade tip geometric parameters on aeroelastically conformable rotor performance and loads characteristics. The model articulated rotors included baseline and torsionally soft blades with interchangeable tips. Sven blade tip designs were evaluated on the baseline rotor and three tip designs were tested on the torsionally soft blades. The designs incorporated a systematic variation in three geometric parameters: sweep, taper, and anhedral. The rotors were evaluated in the NASA Langley Transonic Dynamics Tunnel at several advance ratios, lift and propulsive force values, and tip Mach numbers. Based on the test results, tip parameter variations generated significant rotor performance and loads differences for both baseline and torsionally soft blades. Azimuthal variation of elastic twist generated by the tip parameters strongly correlated with rotor performance and loads, but the magnitude of advancing blade elastic twist did not correlate. (Author).

Download or read book NASA Technical Paper written by and published by . This book was released on 1979 with total page 118 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 1979 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: