Effects of blade plan form on free-space oscillating pressures near propellers at flight Mach numbers to 0.72

Max C. Kurbjun
Aug 1957

In order to obtain information on the effects of blade plan form on the near-field noise of propellers, a series of measurements have been made of the oscillating pressures near a tapered-blade-plan-form propeller at flight Mach numbers up to 0.72. Flight Mach number, power, and engine speed were controlled in an attempt to duplicate the conditions of the flight investigation reported in NACA Technical Note 3417, where oscillating pressures were measured near a rectangular-blade-plan-form propeller.

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