Acoustic performance and flow analysis of a multi-chamber perforated resonator for the intake system of a turbocharged engine

Abstract

A multi-chamber perforated resonator is a type of silencer which can attenuate broadband noise. In order to address the noise issues originating from the intake system of a turbocharged engine, measurement tests are carried out to characterize the range and the amplitudes of the noise frequencies. A transfer matrix method and a non-linear least-squares optimization algorithm are combined in order to design the multi-chamber perforated resonator. A transmission loss test facility is designed on the basis of the two-load method so as to validate the acoustic performance of the resonator. Despite the difference between the amplitude of the transmission loss from the tests and the amplitude of the transmission loss obtained by the transfer matrix method, the shapes of the two curves have the same trend, and the measured transmission loss can meet the design target in the frequency range of interest. From the comparison between the intake noise spectrum with the resonator and the intake noise spectrum without the resonator, it can be seen that this resonator can efficiently attenuate the broadband intake noise of the engine. Also, a computational fluid dynamics flow simulation analysis of the intake system with the resonator is made so that its flow characteristics can be studied. The simulation results show that the air pressure drop of this resonator is slightly higher than that of the straight pipes but is still relatively low. It is also noted that the diameter and the curvature of the pipes have a great influence on the air velocity as well as on the pressure drop.