Experimental Study on Noise Source Identification of Diesel Engine

The noise source identification at rated operating conditions was conducted with the sound intensity method and the typical engine noise characteristics were determined.Then the engine noise in the whole operating conditions was measured with the sound pressure method.Based on the mechanism of combustion noise and mechanical noise,the contribution of typical position to engine noise was researched.The result showed that the noise of corresponding sound pressure point to large sound intensity surface was also large.With the increase of speed and load,the influence of speed on noise surpassed that of load.At high speed,the contributions of rotary parts and valve system to engine noise were larger.