DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
WIND TUNNEL TESTS OF AN OPTIMIZED, MATCHED STIFFNESS RIGID ROTOR
LOCKHEED-CALIFORNIA CO BURBANK
A 10-foot-diameter model of a new type of rigid rotor was tested in the Freon atmosphere of a transonic dynamics tunnel at simulated speeds up to 263 miles per hour. Configurations having 3, 4, and 6 blades with zero blade twist and a 4-blade configuration with six degrees of negative twist were tested. A flexure system eliminated the usual feathering bearings. While a true matched stiffness rotor would have flapping and in-plane stiffness matched along the full length of the blade, the system tested had stiffness matched only in the blade flexure region. The tests were successful, and this new type of rigid rotor appears to offer substantial advantages over previous stiff in-plane rigid rotors by reducing rotor weight, gyro weight and drag, hub drag, control forces, and mechanical complexity.
Approved for public release; distribution is unlimited. Document partially illegible.