基于现有发动机进行新技术方案验证研究是一种快速探索关键技术的途径。主要研究了一种基于常规涡扇发动机发展变循环发动机的设计思路。提出了将高压压气机第1级修改作为核心机驱动风扇级(CDFS),增加选择阀门、前可变面积涵道引射器、后可变面积涵道引射器的总体结构改进方案。描述了该变循环发动机的工作原理,确定了总体性能初步方案,进行了变循环发动机的数值模拟以预估性能收益。计算表明:超声速巡航采用单涵模式,可使推力提高5%～8%;亚声速巡航采用双涵模式,对降低耗油率不明显,但可使发动机进口空气流量增加5%,从而减小进气道溢流阻力以提高发动机的安装性能。

A new testing research on an existing engine provides an efficient way to explore critical engine technology.A new method is proposed to develop VCE (variable cycle engine) from a conventional gas turbine (turbofan) engine.This paper also presents a configuration promotion project with introduction of selector valve,and puts forward VABI (variable area bypass injector) and rear VABI.The first stage of high pressure compressor is changed to a CDFS (core-driven fan stage).The working principle of the VCE is stated.Based on the components′ performance level of conventional turbofan engine,a primary overall performance project is carried out and a numerical simulation on VCE is conducted.The calculation results show that the thrust can be increased by 5% to 8% in supersonic cruise using single bypass mode.Although specific fuel consumption (SFC) cannot be decreased obviously in subsonic cruise using double bypass mode,the engine inlet air flux can be increased by 5%,so the spillover is reduced and installed performance of the engine can be improved.