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Aerodynamic Characteristics of a 4-foot-diameter Ducted Fan Mounted on the Tip of a Semispan Wing
Author: Kenneth W. Mort
Publisher:
Published: 1962
Total Pages: 38
ISBN-13:
DOWNLOAD EBOOK →Power, free-stream velocity, and duct angle of attack were varied at several wing angles of attack to define the aerodynamic characteristics of the ducted fan, wing, and of the ducted fan wing together. At large duct angles of attack, the inside of the upstream duct lip stalled causing a rapid change in the duct pitching moments and an accompanying increase in the power required. At low horizontal velocities, this lip stall would probably limit the rate of descent of a vehicle with a wing-tip-mounted ducted fan. During low-speed, level, unaccelerated flight (30 to 80 knots) it appeared that a vehicle, with a configuration similar to that examined, would require less power if it were supported by a wing and ducted fans than if it were supported only by ducted fans. (Author).
NASA Technical Note
Large-scale Wind-tunnel Investigation of a Ducted-fan -- Deflected-slipstream Model with an Auxiliary Wing
Author: Michael D. Falarski
Publisher:
Published: 1971
Total Pages: 60
ISBN-13:
DOWNLOAD EBOOK →The longitudinal aerodynamic characteristics of a semispan wing dellected-slipstream configuration with a double-slotted flap and and auxiliary wing were determined. The model was powered by two low-pressure-ratio ducted fans. A comparison of static test results with results obtained from various propeller-driven configurations indicates that the turning effectiveness of fan-powered deflected-slipstream configurations can be correlated with propeller-powered configurations with the same flap-chord to slipstream-diameter ratio. The turning effectiveness of the auxiliary wing was essentially the same as would be produced by a conventional slotted flap system with the same flap-chord to slipstream-diameter ratio. The auxiliary wing reduced the thrust required at low speeds as would be expected due to the increase in lifting surface area.
A Selected Listing of NASA Scientific and Technical Reports for ...
Division of Aerodynamic Loads on a Semispan Tilting-ducted-propeller Model in Hovering and Transition Flight
Index of NASA Technical Publications
Author: United States. National Aeronautics and Space Administration
Publisher:
Published: 1960
Total Pages: 448
ISBN-13:
DOWNLOAD EBOOK →The Effectiveness of Three Exit Vane Cascade Configurations for Vectoring the Thrust of a Ducted Fan
Aerodynamics of a Tilting Ducted Fan Configuration
Aerodynamic Characteristics of a Powered Semispan Tilting-shrouded-propeller VTOL Model in Hovering and Transition Flight
Author: Kenneth W. Goodson
Publisher:
Published: 1962
Total Pages: 52
ISBN-13:
DOWNLOAD EBOOK →"An investigation of the aerodynamic characteristics of a powered semispan tilting-shrouded-propeller configuration has been 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. The test results show that large nose-up pitching moments are obtained at transitional speeds of about 40 knots and duct angle of about 70°. Decelerating flight procedures 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° reduces the power required by about 30 percent at 50 knots. Duct-lip stall produces large increases in power required. The results in general 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."--Summary.
