一种直升机/发动机系统最经济旋翼转速综合优化方法

为实现直升机/涡轴发动机的最经济运行,开展了直升机/发动机系统最经济旋翼转速综合优化方法研究。首先,建立简化的直升机需求功率性能计算模型与涡轴发动机性能计算模型,共同构成直升机/发动机综合系统性能计算模型；其次,围绕通过可变动力涡轮转速实现变旋翼转速方式,分别以最小直升机需求功率优化与最低发动机燃油流量为优化目标,进行最经济旋翼转速离线优化,并对比分析两种优化模式对直升机/发动机系统综合性能的影响,揭示不同工况对最经济旋翼转速的影响规律。结果表明：变动力涡轮转速下,优化直升机需求功率未必等同于优化直升机/发动机的总体性能,而桨叶固有的失速与压缩特性,会限制进一步实现直升机最经济运行的能力。此外,采用变动力涡轮转速实现变旋翼转速,几乎不影响压气机与燃气涡轮的工作线,沿着相同的工作线运行可获得更经济的直升机/发动机综合性能。

Integrated Optimization Method of the Most Economical Rotor Speed for Helicopter/Engine System

In order to realize the most economical operation of helicopter/turboshaft engine, an integrated optimization method for the most economical rotor speed of the helicopter/engine system has been studied. Firstly, a simplified performance calculation model of helicopter required power and a performance calculation model of turboshaft engine are established, which together constitute the performance calculation model of the integrated helicopter/engine system. Then, according to one of the variable rotor speed approaches, namely variable power turbine speed (VPT), the minimum helicopter required power and minimum engine fuel flow is taken as the optimization objective respectively to carry out the offline optimization for the most economical rotor speed, the effect of both optimization modes on the overall performance of helicopter/engine is analyzed. Moreover, the variation laws of the most economical rotor speed under different working conditions are revealed. The results show that under VPT mode, the minimum helicopter required power optimization may not be equal to the overall performance optimization of integrated helicopter/engine system. Furthermore, the inherent stall and compression characteristics of the blades limit the ability to achieve the most economical operation of helicopter. In addition, VPT modes hardly has influence on the operating line of compressor and gas turbine, and the superior overall performance of helicopter/engine is available through running along the same operating line.