涡轮风扇发动机紧凑压缩系统气动性能

Aerodynamic performance investigation of a compact compression system for turbofan engine

通过数值方法研究了由2级风扇、4级高压压气机及外涵组成的紧凑压缩系统的气动性能.探讨了双涵双轴压缩系统气动性能的评估方法及数值计算中相应的边界给定方法.通过对紧凑压缩系统的一体化数值模拟,分别获取了风扇及高压压气机的设计转速特性,并与设计值进行了对比,结果表明流量、压比、效率都达到了设计要求,而风扇失速裕度仅为7.8%,低于设计指标.对节流过程中流动分析表明,内涵节流时,压缩系统的失稳起始于高压压气机出口级;外涵节流时,风扇进口级叶尖泄露涡在通道激波作用下发生破裂,导致较大范围的堵塞,是压缩系统失稳的主要原因.

The performance of a compact compression system with fan-bypass-core c ompressor configuration was investigated numerically in this paper.The throttlin g methodology for accessing performance of fan-bypass-core compression system an d its implementation during the numerical simulation was discussed.The calculate d design speed performance of fan and high pressure compressor（HPC） shows that the design targets are achieved for mass flow,total pressure ratio and efficienc y,while the stall margin of fan is only 7.8%,lower than the required value.Analy sis of the flow field evolution shows that,during core nozzle throttling,the sys tem instability is initiated in the exit stage of HPC;during bypass nozzle throt tling,however,the large extent blockage,which is caused by the interaction of ro tor tip vortex and passage shock,may contribute to the instability of the compre ssion system.