Grumman Jet Noise Facility.

Abstract : The jet noise test facility of the Grumman Research Department is described in detail. Hot film anemometers have been used with a specially designed traversing mechanism to measure mean and turbulent velocities in the jet flow. The basic acoustic instrumentation consists of microphones mounted at the ends of three 23-foot booms which swing through the nozzle's axis of symmetry. These microphones provide information on the directionality and strength of the far field noise emanating from the jet. Flow and acoustic measurements made to date are in good agreement with data of other investigators. One of the major unsolved problems of jet noise research is the determination of the distribution of noise sources within the jet flow. (Author Modified Abstract)