Combustion characteristics of direct injection piston aviation kerosene engine

Based on the experiment implemented on a low pressure air-assistant direct injection piston aviation engine, the influence of different start of injection timings, advance ignition angles, excess air ratios on the combustion characteristics was analyzed, and the difference between aviation kerosene and gasoline in the aspect of mixture formation, ignition delay period, flame propagation velocity and anti-detonating quality was compared. The result shows that：the fuel atomization will get higher and the cyclic variation coefficient get lower at the optimal start of injection timing, the cold start for aviation kerosene is harder than gasoline. Aviation kerosenes optimal advance ignition angle is bigger than gasolines under same conditions since its flame propagation velocity is lower than gasoline, and the impact of thermal efficiency on aviation kerosene is more obvious than on gasoline when the optimal advance ignition angle is deviated from the minimum advance for the best torque. Compared with gasoline, aviation kerosene is more suitable for burning in the enviroment with biger fuel mole fraction, when the excess air ratio is with in the range of 0.80 to 0.85, the ignition delay period of aviation kerosene will be the shortest and the cyclic variation coefficient will be the lowest. Under the low speed and high load condition, the knock intensity gets higher significantly. The anti-detonating quality of aviation kerosene is worse than gasoline.