双轴涡喷发动机脉冲停供油时动态过程的数值模拟

在数值模拟双轴涡喷发动机脉冲停供油时动态工作过程中, 考虑到脉冲停供油会引起燃烧效率和涡轮效率恶化, 从而偏离特性图上所示值, 且因实验较难获得上述效率修正关系, 因此提出用实测的高、低压转速曲线代替上述效率做为数值模拟的已知条件。应用这一方法模拟了某型发动机脉冲停供油时的动态过程, 数值结果与实验值基本符合, 并获得该动态过程燃烧效率数据。 

NUMERICAL SIMULATION ON TRANSIENT OPERATION OF TWIN-SPOOL TURBOJET ENGINES DURING PULSATORY FUEL SUPPLY

Since pulsatory supply of fuel in operation of turbojet engines deteriorates both combustion and turbine efficiencies and makes them deviate from data given by characteristic maps.Moreover,it is also hard to obtain an empirical correlation for correcting the deviations of both these efficiencies.A new approach proposed in present study is to replace the two maps of combustion and turbine efficiencies by experimentally measured high pressure and low pressure shaft speed curves,which can be used as the known conditions for differential equations describing transient operation of twin spool turbojet engines.Both Euler′s method and Newton-Rapson′s iteration are used in calculation discretizing for and solving the differential equations.Based on the above mentioned approach,a transient operation of a twin spool turbojet engine during pulsatory supply of fuel has been numerically simulated.The numerical results are in good agreement with those experimental measurements.