Accession Number : AD0018197


Title :   REPORT OF FIRST YEAR'S ACTIVITIES (15 JUNE 1952 - 15 JUNE 1953)


Corporate Author : CESSNA AIRCRAFT CO WICHITA KS


Personal Author(s) : Hinton, Sam


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/018197.pdf


Report Date : 13 Jul 1953


Pagination or Media Count : 26


Abstract : Improved helicopter performance is being sought by the application of boundary-layer control (BLC) to helicopter rotor blades. The possible benefits of BLC include an increase in the maximum lift coefficient (and stalling angle of attack) of the rotor blade to delay the stall of the retreating blade and thereby permit a higher forward speed of the helicopter, and a reduction of the profile drag of the rotor blade so as to reduce the power required for a given lift. Wind-tunnel studies were made on the use of single suction slots located in the forward portion of the top side of the airfoil. Results showed that the stalling angle of the NACA 0015 airfoil could be extended from the normal 14 to about 31, with a correspondingly large gain in maximum lift coefficient, with the use of reasonably low suction quantities. Wind-tunnel data indicated the possibility of using BLC in an intermittent manner to permit great savings in air pumping power.


Descriptors :   *HELICOPTERS , *AERODYNAMIC CHARACTERISTICS , PERFORMANCE(ENGINEERING) , ANGLE OF ATTACK , HELICOPTER ROTORS , ROTOR BLADES(ROTARY WINGS) , AIRFOILS , STALLING , COEFFICIENTS , GAIN , AERODYNAMIC DRAG , DELAY , AIR POWER , AERODYNAMIC LIFT , WIND TUNNELS , BOUNDARY LAYER CONTROL , SUCTION SLOTS , ROTOR BLADES , ANGLES , EXPERIMENTAL DATA


Subject Categories : Helicopters
      Aerodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE