Vibration measurements of an airplane fuselage structure II. Jet noise excitation

Abstract Measured response of a Boeing 737 airplane fuselage structure to jet noise excitation is presented for three test conditions. At take-off, jet noise is the only excitation, but for the two flight conditions considered the excitation is a combination of jet noise and turbulent boundary layer pressures, and jet-noise-induced vibration has to be deduced. Response to jet noise is important at low frequencies where the vibration is well correlated over several fuselage panels in the longitudinal and circumferential directions. Within this frequency range the jet noise is a more effective excitation than is the turbulent boundary layer, but these roles are reversed at higher frequencies. There is no evidence of coincidence between the jet noise excitation and the structure.