Investigation on the combustion cyclic variability in a non-road diesel engine fuelled with diesel/bio-diesel blends

The investigation on combustion cyclic variability is conducted to test with different bio-diesel ratios in 186FA non-road diesel engine blended with bio-diesel. Combustion cyclic variabilities of main combustion parameters are analyzed according to the measured cylinder pressure diagrams of 100 combustion cycles. The results show that, with the increase of blended bio-diesel ratio, the start timing of combustion is advanced and the peak of heat release decreases; and the coefficient of variations (COVs) of the indicated mean effective pressure (p_mi), high maximum cylinder pressure (p_max), and the peak of heat release all have a reducing trend, but the COVs of those corresponding crank angles are larger than that blended with diesel fuel respectively, and the combustion cyclic variability of the maximum rate of pressure rise is prominent. Furthermore, better inter dependency exists between the indicated mean effective pressure and high maximum cylinder pressure, and between the indicated mean effective pressure and the peak of heat release.