Design of Quiet Efficient Propellers

A numerical computation scheme has been developed to determine the sound generated by propellers. A comparison of these calculations to the noise data taken in the the flight test of a propeller driven aircraft shows good agreement. The method is then applied in a parametric study of fixed pitch propellers designed to reduce noise. All these techniques reduce noise while maintaining shaft speed so that the method presented here may be used in a retrofit option for the general aviation fleet.