进口导叶形式对核心机驱动风扇级的影响

以某变循环发动机(VCE)所用核心机驱动风扇级(CDFS)为研究模型,数值模拟了CDFS在真实边界环境下的流动特性,分析了单/双涵道工作模式下,不同形式的可调进口导叶(IGV)对CDFS流动特性及性能的影响机理。结果表明:不同工作模式时,CDFS靠导叶角度的开闭实现大范围的流量调节。单涵道(SB)工作模式时,不同形式的可调进口导叶(VIGV)对CDFS性能的影响差异很小;双涵道(DB)工作模式时采用常规可调导叶(CIGV)会在其吸力面产生较大的流场分离,且流通能力和流量调节范围大大降低。可变弯度导叶通过可转动部分的开闭实现CDFS对流量调节的需求;通过固定部分保证CDFS导叶进口气流攻角基本不变,同时在固定部分和可转动部分连接处所形成的收缩通道的加速效应显著抑制了导叶吸力面的流动分离。可变弯度导叶是适用于CDFS在不同工作模式下性能参数及流量调节需求的可调导叶的形式。

Influence of inlet guide vanes type on core driven fan stage

Depending on the model of the core driven fan stage (CDFS) used by one variable cycle engine(VCE), the flow characteristic of CDFS was simulated under the real boundary environment, the influences of inlet guide vanes(IGV) on CDFS flowfield and performance were analyzed under single bypass (SB)/double bypass (DB) operating modes of VCE. Results showed that CDFS can achieve the wide range flow adjustment by changing the IGV prewhirl angle. When working in SB mode, the influences of variable inlet guide vane (VIGV) on the CDFS were almost the same with the conventional inlet guide vane (CIGV). In DB mode, obvious flow separation was induced on IGV suction surface with CIGV adopted for CDFS, and the flow capacity and the flow adjustment range of CDFS dropped rapidly. But for VIGV, it adjusted the flow through the flap, and kept the attack angle by the strut, meanwhile the link section of the strut and the flap can accelerate the flow, which can restrain the flow separation. VIGV is the desirable IGV type for CDFS, which can meet the performance parameters and flow adjustment requirements under different operating modes.