Analysis and Development of Inline Helmholtz Resonator through Computer Simulation for Elimination of Low Frequency Intake Noise Character

The air induction system of an automobile engine contributes to the noise level generated by a passenger car. The contribution is significant in the perception of vehicle noise quality. There is a great value in reducing and controlling passenger car air induction noise.

Helmholtz resonators are widely used for noise reduction in vehicle induction and exhaust system. These resonators are usually mounted as side branch volumes to the main induction system, occupying larger space. The design presented here describes the use of compact inline Helmholtz resonator (Patent application no. 190/Bombay/98) for elimination of low frequency noise character in passenger car. Finite element model of the acoustic cavity of induction system along with the inline resonator is made. The transmission loss characteristics computed analytically correlates very well with the experimental transmission loss characteristics. The principle function of the new inline resonator is the reduction of low frequency character of inlet noise. The potential for improved engine performance is also discussed. The resonator is packaged in unique way to occupy available space under the hood.