基于高导流量特性的发动机性能评估方法

Engine performance evaluation method based on the flow characteristics of high-pressure turbine guide vane

在发动机性能分析中,高压涡轮导向器的冷却用气流量与压气机进口流量的比值为固定值。而实际涡轮冷却用气流量会受到冷气流路进出口压差、流通面积、流阻等因素的影响而发生变化,使发动机性能仿真精度与实际性能存在偏差。为进一步提高发动机的性能仿真精度,提出了一种基于高压涡轮导向器流量特性的建模方法,并以此完善了核心机性能计算模型,利用该模型对某型核心机性能参数进行计算。计算结果表明:对某型核心机,在考虑高导流量特性后,实际高导冷气量减少,且冷气量对冷气流路总压恢复系数的变化较为敏感。在核心机性能计算中采用高导冷气流量修正后,燃烧室出口总温下降1%~2%,核心机温比上升0.2%~0.45%,单位循环功增大0.24%~0.48%,核心机压比和单位循环功耗油率变化较小。

In engine performance analysis,the ratio of the cooling air flow of high-pressure turbine guide vane to compressor inlet flow is a fixed value.However,the actual bleed air flow of the turbine is affected by some factors,such as the pressure difference between the inlet and outlet of the cooling air flow path,flow area and flow resistance,resulting in deviations between the current simulation accuracy and actual performance of the engine.To further improve the simulation accuracy of engine performance,a modeling method based on the flow characteristics of high-pressure turbine guide vane was proposed.The computational model of the core engine performance was improved based on this method,and the performance parameters of one core engine were calculated with this model.The numerical results show that,for this core engine the actual cooling air flow of turbines decreases after considering the flow characteristics of high-pressure turbine guide vane,and the cooling air flow is more sensitive to the change of the total pressure recovery coefficient of the cooling air flow path.In the performance calculation of the core engine,after using the cooling air flow correction of high-pressure turbine guide vane,the total temperature at the outlet of the combustion chamber decreases by 1%to 2%,the tempera‐ture ratio of the core engine increases by 0.2%to 0.45%,the unit cycle power increases by 0.24%to 0.48%,and the pressure ratio of the core engine and the fuel consumption rate per unit cycle power change relatively little.