Systematic investigations were performed on a variety of probes to determine their potential for possible application as sensors attached to helicopter blades to measure both the instantaneous angle of attack as well as the dynamic head during actual flight operations. After some preliminary considerations a sensor of essentially spherical shape, about 30 mm in diameter, was designed. The sensor was provided with three pressure ports, and it housed two pressure transducers required for sensing the prevailing pressures acting outside on the surface. The sensors were subsequently tested in the laboratory under a variety of flow conditions to determine their aerodynamic characteristics. Two series of tests were performed: in the first series the sensor was fixed in space while exposed to steady uniform flow, while in the second series the sensor was made to oscillate, thus simulating the cyclic pitch change of the helicopter blades. While the cyclic pitch frequencies were of about the same magnitude as encountered in flight, the flow velocities during tests fell well below those experienced in a rotating blade. The tests showed that the sensors performed satisfactorily under low subsonic flow conditions with frequencies not exceeding five Hz.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Sensor for measuring instantaneous angle of attack of helicopter blades


    Contributors:

    Publication date :

    1980-06-01


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English





    Quieter helicopter blades

    Online Contents | 1994


    ATTACK ANGLE MEASURING APPARATUS AND ATTACK ANGLE MEASURING METHOD

    HONDO TAKATOSHI | European Patent Office | 2019

    Free access

    Stalling of Helicopter Blades

    Gustafson, F B / G C Myers, JR | NTRS | 1946


    Stalling of helicopter blades

    Gustafson, F.B. / Myers, Jr., G.C. | Engineering Index Backfile | 1946