Wind Tunnel Vibration Tests Of A Four Blade Single Rotating Pusher Propeller

Summary: Vibration tests of a four-blade single-rotating propeller operating in a simulated pusher condition were performed because the combination of wake and downwash behind a wing was expected to provide serious excitation for reactionless vibrations of propellers with four or more blades. The tests were conducted in the LMAL 16-foot high-speed tunnel with a wing mounted at thrust-axis level ahead of the propeller; the blade sections at three-fourths the propeller radius operated at approximately twice their chords behind the trailing edge of the tapered wing at their closet position. Measurements of propeller vibratory stress were made for various airspeeds, engine speeds, and engine powers.

Reproductions of reports, some declassified, of research done at Langley Memorial Aeronautical Laboratory during World War II. The order of reports does not represent when they were chronologically issued. Reference to the original version of each report is included.