变循环发动机起动建模及控制规律研究

Research on starting modeling and control law of variable cycle engine

为研究双外涵变循环发动机起动控制规律,基于部件级建模方法,考虑可调部件变几何特性处理和旋转部件低转速特性外推,采用流量平衡方法构建共同工作方程组,建立变循环发动机起动数学模型。通过改变单个几何调节量,包括风扇、核心机驱动风扇(CDFS)和压气机导叶角度,低压涡轮导向器面积,前涵道引射器(FVABI)面积、后涵道引射器(RVABI)面积和尾喷管喉道面积,采用单因素分析方法,研究其对起动性能的影响,获得几何变量影响矩阵,并基于此开展起动控制规律研究。研究表明:控制规律的风扇导叶、核心机驱动风扇导叶、前涵道引射器和喷管均置于全关闭位置,低压涡轮导向器处于最大位置,后涵道引射器面积和压气机导叶角度随转速下降。经试验验证,起动控制规律正确可行,变循环发动机起动成功。研究结论对变循环发动机起动控制规律和起动性能设计提供了参考。

To research the starting control law of double-culvert variable cycle engine,based on the modeling method of component,the method of air mass flow balance was used to establish corresponding common working equations,and the double-culvert variable cycle engine starting model was established by considering the processing method of variable geometry characteristics for adjustable components and the low speed characteristic extrapolation method of the rotating components.Through using single factor analysis method,it changed single geometry adjustments,including the guide vane angle of fan,core driven fan stage(CDFS)and compressor,the throat area of low pressure turbine,the area of front variable area bypass injector(FVABI),rear variable area bypass injector(RVABI)and exhaust nozzle,and studied the influence on the starting performance of engine to obtain the influence matrix of geometric variables.Based on this,starting control law was researched.Research showed that in this starting control law,the guide vane angle of fan and CDFS,FVABI and nozzle were kept at closed position,and the throat area of low pressure turbine kept at the max position,whilst the area of RVABI and the guide vane angle of compressor decreased with the increase of rotation speed.Test result showed that,the starting control law was correct and feasible,and variable cycle engine started successfully.The conclusion provides a reference for variable cycle engine control law and starting performance design.