The Development of an Intake Silencer for a Two-Stroke Cycle-Spark Ignition Engine

In the case of small outboard motors, intake noise is the main sound source. Consequently, intake silencer improvement is a significant factor in the development of outboard motors.

A theoretical simulation was developed to aid the design of improved silencers. This simulation was based on the one-dimensional transfer matrix method (2,3)* and was validated by measurements recorded from a 2-channel FFT experimental testing apparatus. The resonance and anti-resonance characteristics of the measured and calculated results showed good consistency.

The simulation technique was utilized to develop an improved configuration and evaluation on a running engine indicated a significant noise reduction.

This study has demonstrated that the simulation technique is an effective silencer development method.