Characteristics of Noise Reduction in Helmholtz Resonator in Exhaust Systems

Abstract

The Helmholtz resonator not only reduces exhaust noise in resonance frequency, but also increases in other frequencies. The silencer property can control the damping in the neck of the Helmholtz resonator. In order to obtain the damping, the neck diameter must be small. Because the particle velocity is high at the neck due to the high-pressure fluctuation in the exhaust system, the pressure drop is high at the narrow pipe. When a Helmholtz resonator is designed, it is advised to control the damping at the neck diameter and the frequency at the neck length.