STUDY OF THE EFFECT OF OPERATING PARAMETERS ON ENGINE NOISE OF DI DIESEL ENGINE USING SOUND INTENSITY TECHNIQUE

Abstract

Among the various parameters of interest, which have the potential of influencing engine noise, operating parameters are the fundamental ones and the effect of these parameters on engine noise has been widely investigated by the researchers. This report focuses on the investigation for the effect of two important operating parameters viz, engine speed and engine load on the over all levels- of engine noise using sound intensity technique. An experimental set-up has been prepared for measuring sound intensity of a small single cylinder DI diesel engine under selected operating conditions. Then experiments have been conducted to obtain sound intensity and sound power for five engine surfaces viz, front, right, left, back and top in the frequency range from 200Hz to 4000Hz. Intensity mapping, Intensity spectrum and Sound Power spectrum have been developed for five engine surfaces using Noise Source Identification software. Three-dimensional surface plots for intensity have been created for. better visualization. Sound Power variation with frequency. of different engine surfaces have been studied under selected operating conditions. Sound Power radiation of important noise radiating components viz, flywheel, pulley and engine block etc. have been presented for different combinations of operating parameters. Finally significant noise radiating components have been identified and some methods to decrease the engine noise radiation have been discussed. iii