AERODYNAMIC CHARACTERISTICS OF A POWERED SEMISPAN TILTING-SHROUDED-PROPELLER VTOL MODEL IN HOVERING AND TRANSITION FLIGHT
Abstract
An investigation of aerodynamic characteristics of a powered semispan tilting-shrouded-propeller configuration was conducted in the 17-foot test section of the Langley 300-MPH 7- by 10-foot tunnel. The wing had an aspect ratio of 2.67 (based on wing span of 60 inches), a taper ratio of 0.67, and an NACA 2418 airfoil section with a 15-inch-diameter shrouded propeller mounted on the tip. Results show that large nose-up pitching moments are obtained at transitional speeds of about 40 knots and duct angle of about 70 degrees. Decelerating flight produces further increases in the nose-up moment. Ground proximity reduces the nose-up pitching moments. The large nose-up moments can be trimmed by use of duct-exit control vanes. The results show that unloading the duct (shroud) by flying at a wing angle of attack of 15 degrees reduces the power required by about 30 percent at 50 knots. Ductlip stall produces large increases in power required. Results show that full-scale aerodynamic simulation can be made with small-scale wind-tunnel models if duct-lip separation at low Reynolds numbers is avoided. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1962
- Accession Number
- AD0268839
Entities
People
- Kalman J. Grunwald
- Kenneth W. Goodson
Organizations
- National Aeronautics and Space Administration