环境温度对涡扇发动机地面起动性能影响试验研究

Effect of temperature on ground starting performance of turbofan engine

为获取涡扇发动机在不同环境温度下地面起动性能,开展某发动机整机地面起动试验,结果发现:(1)温度过低或过高都会造成起动机脱开时间的增加,但前者是由于温度过低时点火性能下降造成的,后者是因为温度过高导致起动机入口压力减低造成的;(2)发动机起动过程中的最高实际排气温度与环境温度基本呈现出线性增长关系,最高换算排气温度随环境温度变化呈现出两边高、中间低的趋势;低温条件下由于滑油粘性的显著增加导致最高换算排气温度升高,高温条件下由于起动机做功减小导致最高换算排气温度升高;(3)低温条件下燃烧室温度较低,不利于燃油的雾化、点火,造成点火时间的延迟,导致多余的燃油在气流的作用下充满涡轮、尾喷管等下游部件。点火成功后,火焰迅速引燃下游部件中的油气混合物,产生发动机爆燃、喷火现象。

The ground starting performance of the turbofan engine at different temperature was analyzed by experiments,and the conclusions were as follows:①The time of starter disconnection would increase when the temperature was too high or too low;when the temperature was too low,the ignition property of the combustor would decrease;when the temperature was too high,the inlet pressure of the starter would decrease;②The actual highest exhausted temperature was basically linear with the ambient temperature,while the highest corrected exhausted temperature increased as the temperature decreased at low ambient temperature or increased at high ambient temperature;the increase of lubricating oil viscidity at low ambient temperature resulted in the increase of corrected exhausted temperature,while the decrease of starter power at high ambient temperature resulted in the increase of corrected exhausted temperature;③Due to the low temperature,the atomization and ignition property of the combustor were decreased,which resulted in the delay of ignition,and the fuel were spread in the downstream assemblies such as turbine and nozzle;when the engine ignited successfully,the flame would ignite the air-fuel mixture in the downstream assemblies,and then the exhaust flame happened.