Characteristic of combustion noise in a non-road diesel engine fueled with bio-diesel

To investigate the characteristic of combustion noise in a non-road diesel engine, tests with different bio-diesel ratio fuel were conducted. According to the cylinder pressures of 100 consecutive combustion cycles, combustion noise was analyzed. The results show that, with the increase of blended bio-diesel ratio, both the maximum cylinder pressure and the maximum rate of pressure rise all have increasing trends. The cylinder pressure level at frequency of 1000 Hz increases with blended bio-diesel ratio. In the test with B50 fuel, the biggest value of combustion noise appears and its value is about 0.5 dB(A) bigger than that of diesel at full load. The blending of bio-diesel has a dual effect on combustion noise which contributes to the increase of combustion noise and the reduction of it. At the same time, advance angle of fuel supply has great influence on combustion noise of diesel engine fueled with bio-diesel and fuel supply delay can properly reduce combustion noise of diesel engine effectively.