[소음·진동] 흡음재의 음향특성 예측에 의한 밀폐계의 내부 소음저감

For the purpose of finding out the sound field characteristics in a cavity of a rectangular enclosure, analytical and experimental studies are performed with white noise input. Experimental method using two-microphone impedance tube measures the impedances of foamed aluminum. Foamed aluminum is well known metallic porous sound absorption material which has excellent properties of light weight and high absorbing performance. And predicted impedances of foamed aluminum is compared with measured impedance. Predicted acoustical parameters of foamed aluminum are applied to the theoretical analysis for predict sound pressure field in the cavity. The sound absorption effects through measurements are compared with prediction in both cases with and without foamed aluminum lining in the cavity of the rectangular enclosure