B343
DESIGN: UniCopter ~
Rotor - Blade - General
Outside Helicopter
Blade Specifications:
Blade loading = 57.8 lb/sq-ft.
Blade twist = -10º. They would change it to -8º on any future ABC craft.
Blade taper ratio is 2:1. On any future ABC craft, they would have a taper ratio of 3.6:1, to improve high-speed performance.
The blade planform has a mean chord of 1.44 ft. The airfoil section decreases from a 63 (230)-224A at 20% radius to a 63 (230)-213A at 62% radius. Then it transitions to a 23012 (64) section at 72% of radius. The 23012 (64) section is held constant from 72% to the tip. The rotor radius is 18 feet.
"Another indication of blade stiffness is the static deflection of the blade under dead weight load. For a typical ABC blade the static deflection is only about 0.2 percent of the blades radius." [I assume that dead weight load is simply the weight of the blade]. As well, if the spar material was changed from titanium to boron fiber then the weight would be 0.74/1 and the deflection would be 0.46/1 as much. ~ both data from [The ABC Helicopter] article in Feb 1969
For Additional Sikorsky ABC Blade Information see the item pages listed on Unicopter ~ Rotor - Blade General (all blades)
For Sikorsky ABC Rotor Specifications
see; DESIGN: UniCopter ~ Rotor ~ Sikorsky ABCFor Sikorsky ABC General Information
see; OTHER: Helicopter - Outside - Coaxial - Sikorsky ~ XH-59A ABC
Flettner FL-282:
The NACA 23017 was used on the Flettner-282 intermeshing helicopter. On this helicopter, it had 4 degrees twist.
Kaman Seasprite:
The KM230XX 11.47% (@ tip) and NACA 230 14.86% (@ root) is used on the Kaman Seasprite. On this helicopter, it has 10 degree of linear twist.
Other Outside Information
Reports:
NASA ~ Stiffness Characteristics of Composite Rotor Blades With Elastic Couplings:
http://techreports.larc.nasa.gov/ltrs/PDF/1997/tp/NASA-97-tp3641.pdf Have hard copy.Matrix method for obtaining spanwise moments and deflections of torsionally rigid rotor blades with arbitrary loadings. NACA TN 4304; Aug 1958. Have copy on disk ~ search TN 4304.
AIAA-98-2881 IMPORTANT SCALING PARAMETERS FOR TESTING MODEL-SCALE HELICOPTER ROTORS, 23 Jun 98, Have copy on disk and hard copy.
Kevin W. Noonan, Susan L. Althoff, Dhananjay K. Samak and Michael D. Green , Effect of Blade Planform Variation on the Forward-Flight Performance of Small-Scale Rotors , NASA TM-4345 AVSCOM TR-92-B-005 , April 1992 , pp. 83 . Format(s):
Postscript, or PDF
Patents:
See:
DESIGN: SynchroLite ~ Rotor - Blade - Composite ~ Relevant PatentsUniCopter
Consider the Wortmann FX 74-CL5-140 for inverted use as horizontal stabilizer on UniCopter.
Posting on ENG-Tips: March 23, 2003
If you are really serious about building flying blades, email me at
Crazy Idea:
Would an airfoil that had a different NACA numbers on the top and bottom still maintain a center of pressure at 25% for all angles of attack? Say NACA0009 top tip, NACA0004.5 bottom tip. NACA0015 top root. NACA0007.5 bottom root. Apparently not ~ see NACA 0015_0016.dat in NVfoil
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Last Revised: September 29, 2004