低压转子分出功率对高空长航时无人机发动机的影响

建立了高空长航时无人机发动机性能计算模型,引入雷诺数对发动机部件性能影响的修正,编制了相应的计算程序.计算分析了不同类型的中小推力涡扇发动机在高空条件下低压转子分出功率对发动机和核心机状态的影响,以及高/低压转子同时分出功率对发动机的影响,并对分出功率在高、低压转子的分配比例进行了分析.结果表明:在高空条件下,与高压转子分出功率相比,低压转子分出功率能明显改善无增压级涡扇发动机的风扇/压气机喘振裕度和带增压级涡扇发动机的增压级喘振裕度,能在保证发动机稳定工作的前提下,大幅度提高无增压级涡扇发动机的高空分出功率能力,有效提高带增压级涡扇发动机的高空分出功率能力,此外,低压转子分出功率可使核心机的转速、换算流量、增压比提高9%~14.8%,能有效地挖掘核心机的潜力. 

Effects on extracting power from low-pressure spool on HALE UAV engine

The mathematical models of high-altitude long-endurance unmanned aerial vehicles (HALE UAV) engines with the corrected method of Reynolds number for engine components characteristics were built, and the corresponding programs were developed. The effects of extracting power from low-pressure spool on different small and medium thrust turbofans engine and the core engine, as well as the effects of extracting power from two spools on the engine were calculated and analyzed under high-altitude flight condition; the proper proportion of power extraction between different spools was analyzed. It is shown from the computation results that compared with extracting power from high-pressure spool under high-altitude flight condition, extracting power from low-pressure spool can observably improve the fan/compressor surge margins for turbofan without booster and the booster surge margins for turbofan engine with booster, remarkably increase the power extraction of turbofan without/with booster on the premise of maintaining engine operation stability; also this can realize a 9% to 14.8% improvement in spool speed, correlated mass flow and pressure ratio of the core engine for developing potential of the core engine.