Complex geometry automotive muffler sound transmission loss measurement by experimental method and 1D simulation correlation

Abstract

A muffler is a device to attenuate noise from the exhaust. The muffler performance determined by the acoustic performance is called sound transmission loss (STL). This paper aims to measure the STL experimentally and correlated with the 1D simulation result. STL was measured using the impedance tube. Four-pole method (microphone) and two-load method were applied to measure the STL. The STL was also determined through the 1D simulation tools software. Three types of mufflers STL were measured; small expansion chamber, big expansion chamber and complex muffler. The respective error between simulation and experiment were 0.17%, 7.89%, and 11.40%. Hence, the STL experiment result was well correlated with the 1D simulation model.