Noise Reduction Measurements On Stiffened And Unstiffened Cylindrical Models Of An Airplane Fuselage PDF Download

Noise-reduction measurements are presented for a stiffened and an unstiffened model of an airplane fuselage. The cylindrical models were tested in a reverberant-field noise environment over a frequency range from 20 Hz to 6 kHz. An unstiffened metal fuselage provided more noise reduction than a fuselage having the same sidewall weight divided between skin and stiffening stringers and ring frames. The addition of acoustic insulation to the models tended to smooth out the interior-noise spectrum by reducing or masking the noise associated with the structural response at some of the resonant frequencies. Willis, C. M. and Mayes, W. H. Langley Research Center NASA-TM-85716, L-15699, NAS 1.15:85716 RTOP 505-33-53-03...