重油航空活塞发动机技术路线分析

Assessment of heavy fuel aircraft piston engine types

分析了重油航空活塞发动机的两条技术路线:点燃式(Otto循环)和压燃式(Diesel循环)。点燃式重油航空活塞发动机功重比较高,但是燃油消耗率高,存在爆震、起动困难、电磁兼容性较差、可靠性较低、功率覆盖范围较小等弱点。缸内直喷、气动喷嘴和高能点火技术是点燃式发动机需攻克的关键技术。压燃式重油航空活塞发动机燃油消耗率低、续航能力强、电磁兼容性较好、可靠性高、功率覆盖范围较大,但是功重比较低、振动较大。高功重比、先进电控及燃油喷射、可调高压比增压技术是压燃式发动机需攻克的关键技术。研究了目前重油航空活塞发动机的主要案例,结果表明:点燃式和压燃式方案均是可行的,且各有一些关键技术需要攻克,压燃式技术路线将是未来主流。

The objective of this study is to assess spark ignition （Otto cycle） and compression ignition （Diesel cycle） engines as heavy fuel aircraft piston engines. Spark ignition aircraft engines give a higher power to weight ratio, but have higher specific fuel consumption （SFC）, knocking, poor starting, higher electro magnetic interference （EMI）, lower reliability and narrower power regions. Spark ignition systems use direct injection, pneumatic atomizers and high energy ignition systems. Compression ignition aircraft engines have lower SFC, improved range, lower EMI, higher reliability and wider power regions, but have worse power to weight ratios and more vibration. Compression ignition engines have advanced electronic controls, fuel injection systems and variable high-pressure ratio superchargers. The assessments show that both approaches are feasible with some technical challenges, with compression ignition engines as the more promising approach.