点燃式航空活塞发动机燃料适应性试验

A test bench of a spark-ignition two-stroke direct injection aviation piston engine was built to study the fuel adaptability of the engine. The performance and combustion characteristics of the engine fuelled with gasoline and aviation kerosene were compared and studied，respectively. The influence of ignition advance angle and excess air-fuel ratio on the performance and combustion characteristics of kerosene engines was also studied. The research results indicate that，due to their similar low calorific value and theoretical air-fuel ratio，the power and torque of the engine when fueled with kerosene can reach over 96% of those when fueled with gasoline under low loads. Under high load，the use of kerosene is limited by knock，resulting in a 10%—12% decrease in engine power compared to gasoline. Reducing the spark timing can reduce the knock intensity of kerosene engines，but a too small ignition advance angle can lead to a decrease in output power and an increase in cyclic variation. When the lambda is 1.1，the knock intensity of the aviation kerosene engine is the highest. Reducing the excess air coefficient can more effectively reduce the knock intensity of the kerosene engine than increasing it. At the same time，it can increase the engine output torque and reduce cyclic variations，but lead to an increase in fuel consumption of kerosene engines.