Sound from dual-rotating and multiple single-rotating propellers

Harvey H. Hubbard
July 1948

Sound measurements for static conditions in the tip Mach number range 0.37 to 0.89 are presented for three different dual-rotating-propeller configurations and one combination of two single-rotating propellers operating side by side in the same plane of rotation. The results obtained are compared with a theoretical analysis of the problem and excellent agreement is found.

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