变循环发动机地面起动建模及控制规律设计方法

Ground starting modeling and control law design method of variable cycle engine

针对旋转部件等熵效率不连续的问题,提出使用换算扭矩代替等熵效率的方法,给出了旋转部件低转速特性拓展方法并获取了旋转部件的全转速特性。提出了可考虑点火及燃烧稳定性的燃烧室稳定性模型,最终建立了变循环发动机部件级整机起动模型。考虑了变循环发动机的8个可调参数,采用差分进化算法对变循环发动机在双外涵及单外涵模态下的起动过程进行了优化。结果表明:变循环发动机在双外涵及单外涵模态下的起动时间分别为17.2 s与12.8 s;双外涵模态下,需要调节燃油流量、喷管喉部面积与后可变面积涵道引射器外涵面积;单外涵模态下,需要调节燃油流量、喷管喉部面积与低压涡轮进口导叶面积;迎风来流马赫数为0.04时,变循环发动机在双外涵与单外涵模态时的起动时间比静止状态均减少0.2 s。

To solve the problem of discontinuous isentropic efficiency of rotating components,a method of using correct torque instead of isentropic efficiency was proposed. The extrapolation method of low speed characteristics of rotating components was given,and the full speed characteristics of rotating components were obtained. A burner stability model considering ignition and burn stability was proposed. Finally,a component-level starting model of the variable cycle engine was established. Considering the eight variable parameters of the variable cycle engine,the differential evolution algorithm was used to optimize the starting process of the variable cycle engine in the double bypass and single bypass modes. The results showed that the starting time of the variable cycle engine in the double bypass and single bypass modes was 17. 2 s and 12. 8 s,respectively. In the double bypass mode,the fuel flow,nozzle throat area and outer bypass area of rear variable area bypass injector need to be adjusted. In the single bypass mode,the fuel flow,nozzle throat area and low pressure turbine inlet guide vane area need to be adjusted. When the free stream Mach number was equal to 0. 04,the starting time of the variable cycle engine in the double bypass and single bypass modes was 0. 2 s less than the static state.