MEASUREMENTS OF THE SOUND-TRANSMISSION CHARACTERISTICS OF MODEL AIRCRAFT FUSELAGES USING A RECIPROCITY TECHNIQUE

A reciprocity technique for calibrating a structure as a converter of applied pressure fields into sound, described in a previous paper, has been applied to a set of model fuselage structures. The resulting transfer functions have been used to predict the sound pressure generated in the enclosed volume by theoretical propeller pressure fields acting on the fuselage external surface. The effects of forward flight speed are investigated, and the extent of the region of the propeller field principally responsible for the internal sound is identified. Extension to full scale application is proposed.