Theoretical Analysis of Compressor Noise

The noise radiated by rotor‐stator and stator‐rotor interactions in a duct of negligible length has been analyzed with the aid of the author's general theory. Explicit analytic results for rotating fluctuating source patterns have been found, which reduce to the case of Gutin for the steady propeller case with no axial velocity, and to Garrick and Watkins' results for the propeller problem with axial velocity. Computed results of over‐all power and directionality will be presented for several basic cases, and the practical implication of these theoretical results will be discussed. [This work has been supported by the National Aeronautics and Space Administration under contract.]