Accession Number : AD0046678


Title :   INVESTIGATION OF THE THWAITES AIRFOIL PRINCIPLE AS APPLIED TO HELICOPTER ROTOR BLADES


Corporate Author : ARNOLD (LEE) ASSOCIATES INC NEW YORK


Personal Author(s) : ARNOLD, L ; YUAN, S W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/046678.pdf


Report Date : Jan 1954


Pagination or Media Count : 86


Abstract : A performance calculation has been carried out for the purpose of comparing the Piasecki XH-16 rotor vith the Karman-Yuan rotor. The two rotors ,atre asi%ned identical in size and lifting capacity (rotor diameter 82 ft, gross weight 36600 lbs). The Piasecki rotor blade is equipped with an NACA 0015 airfoil and the Karman-Yuan rotor blade vith an elliptical airfoil of 18% thickness chord ratio and cyclic flap control. The controllable lift distribution along the blade span of the Karman-Yruan rotor is achieved by varying the spanwise flap location and applied boundary layer suction. Due to the high lift coefficient employed in the Karman-Yuan rotor blade it was found that a lower rotational speed can be used to sustain the same gross wieght as does the XH-16.


Descriptors :   *HELICOPTER ROTORS , *BOUNDARY LAYER CONTROL , BOUNDARY LAYER , STALLING , FLAPS(CONTROL SURFACES) , HIGH LIFT , AERODYNAMIC LIFT , LIFT TO DRAG RATIO


Subject Categories : Aerodynamics
      Helicopters


Distribution Statement : APPROVED FOR PUBLIC RELEASE