Vibration Mode Analysis for Controlling Noise Emission from Automotive Diesel Engine

The vibration mode analysis of an automotive diesel engine for the purpose of obtaining a lower level of noise emission will be described in the paper.

Since the noise emission corresponds to the vibration of certain components of the engine, the vibration of engine structure was analyzed in several running conditions.

Vibration distribution shows a natural vibration mode which was proven by coincidence with the result obtained by modal analysis.

When measurement of the vibration mode is very difficult due to the high mechanical impedance and especially the big damping factor of the component, a new method of vibration mode analysis for the engine component excited by cylinder pressure was proven to be useful.

Some attempts for controlling the noise and an analysis of damping effects will also be described in the paper.