114 Development of Sound Prediction Technique for Automobile Engine Intake System including Porous Duct : Prediction Technique for Sound Propagation Attenuation in Porous Duct

Abstract

Porous duct is effective to attenuate resonant sound of engine intake systems. When we design that system reasonably, we must decide proper length and suitable position of porous duct set in that system to attenuate resonant sound effectively. We proposed the method to determine the transfer matrix of porous duct, which is important for acoustical analysis of that system.