DTIC AD0880676: Helicopter Rotor Rotational Noise Prediction and Correlation. Volume 2. Documentation of Noise Prediction Computer Program

by: Defense Technical Information Center

Publication date: 1970-11-01

Topics: DTIC Archive, Schlegel, Ronald G, UNITED TECHNOLOGIES CORP STRATFORD CT SIKORSKY AIRCRAFT DIV, *AERODYNAMIC NOISE, *HELICOPTER ROTORS, COMPUTER PROGRAMS, CORRELATION TECHNIQUES, MATHEMATICAL PREDICTION, PRESSURE, ROTATION,

Collection: dticarchive; additional_collections

Language: English

A computer program for rotational noise prediction is documented. The program was developed as a part of a study to develop more accurate methods for predicting rotational noise levels under conditions of nonuniform inflow over the rotor disc. The computer program will calculate the root-mean-square sound pressure level for up to the 10th harmonic of rotor noise at any field point in the near or far field outside of the rotor disc. Noise levels can be calculated either from a rectangular chordwise distribution of pressure or from the measured chordwise distribution. Although the report concentrated on a helicopter rotor, the analytical results are applicable to propellers in general.