The Research of Noise Characteristics and Noise Source Identification for Diesel Engine

A diesel engine was taken as a certain type of object,the engine noise and the main components near field noise of different working conditions were measured,and the noise source identification was carried out combined with spectral analysis. The results show that,the engine noise in the calibration working conditions was 106.3dB(A). The engine noise increased as the speed increased during the same loads,the engine loads had little effect on the noise in the high speed. The parts of the higher near field noise were oil pump,oil pan,crankshaft pulley and air filters. The intake noise was main source in the low speed,the peak of(120~125)Hz was consistent with the cyclical pressure fluctuation frequency,and the peak of 315Hz was consistent with the column resonance frequency. The column resonance noise was higher than the cyclical pressure fluctuation noise.