Investigation of a Free-Tip Rotor Configuration for Research on Spanwise Life Distributions and Wake Velocity Surveys of a Semi-Span Wing with a Discontinuous Twist

Investigation of a Free-Tip Rotor Configuration for Research on Spanwise Life Distributions and Wake Velocity Surveys of a Semi-Span Wing with a Discontinuous Twist
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 208
Release: 2018-07-25
Genre:
ISBN: 9781724264589

A wind tunnel test was conducted in the NASA Ames 7 x 10 Foot Wind Tunnel to investigate the lift distribution on a semi-span wing with a discontinuous change in spanwise twist. The semi-span wing had a tip with an adjustable pitch angle independent on the inboard section pitch angle simulating the free-tip rotor blade when its free-tip is at a deflected position. The spanwise lift distribution over the wing and the tip were measured and three component velocity surveys behind the wing were obtained with a three dimensional laser Doppler velocimeter (LV) with the wing at one angle of attack and the tip deflected at different pitch angles. A six component internal strain gage balance was also used to measure total forces and moments on the tip. The three dimensional lift was computed from the two dimensional life distributions obtained from the LV and from the strain gage balance. The results from both experimental methods are shown to be in agreement with predictions made by a steady, three dimensional panel code, VSAERO. Fortin, Paul and Kumagai, Hiroyuki Unspecified Center NASA-CR-184948, NAS 1.26:184948 NCC2-175...

Low-Speed Wind-Tunnel Test of an Unpowered High-Speed Stoppable Rotor Concept in Fixed-Wing Mode

Low-Speed Wind-Tunnel Test of an Unpowered High-Speed Stoppable Rotor Concept in Fixed-Wing Mode
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
Total Pages: 56
Release: 2018-10-29
Genre:
ISBN: 9781729371077

An experimental investigation of the M85, a High Speed Rotor Concept, was conducted at the NASA Langley 14 x 22 foot Subsonic Tunnel, assisted by NASA-Ames. An unpowered 1/5 scale model of the XH-59A helicopter fuselage with a large circular hub fairing, two rotor blades, and a shaft fairing was used as a baseline configuration. The M85 is a rotor wing hybrid aircraft design, and the model was tested with the rotor blade in the fixed wing mode. Assessments were made of the aerodynamic characteristics of various model rotor configurations. Variation in configurations were produced by changing the rotor blade sweep angle and the blade chord length. The most favorable M85 configuration tested included wide chord blades at 0 deg sweep, and it attained a system lift to drag ratio of 8.4. Lance, Michael B. and Sung, Daniel Y. and Stroub, Robert H. Ames Research Center; Langley Research Center...

Aeronautical Engineering

Aeronautical Engineering
Author:
Publisher:
Total Pages: 580
Release: 1971
Genre: Aeronautics
ISBN:

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)