双外涵压缩系统中部件匹配规律的分析

Analysis of Component Matching Phenomenain a Double Bypass Compression System

关键词:  双外涵发动机  一体化通流方法  部件匹配  节流

Key words:  Double bypass engine  Integrated throughflow method  Component matching  Throttling

摘要:

多重外涵道和面积可调阀门使得双外涵变循环发动机(DBE)的压缩部件(风扇、核心机驱动风扇级和高压压气机)之间的气动关联变得复杂。合理地匹配各压缩部件是DBE压缩系统设计的一个首要任务。为了探索DBE压缩系统的设计准则，利用通用的一体化通流计算程序对一个定制设计的DBE压缩系统的部件匹配规律进行了研究，分析了基准匹配状态和两个节流过程(第一外涵道节流和第二外涵道节流)中各部件的匹配状态。对于本文所研究的双外涵压缩系统，通流计算结果表明，在基准匹配状态下，核心机驱动风扇级(CDFS)和高压压气机(HPC)的展向不匹配使得压缩系统的总压比下降了2%、效率降低了0.002。第一外涵道节流会显著改变HPC进口级的匹配状态，而对后面级和CDFS的影响不大。第二外涵道节流改变了CDFS的进口流动剖面，使得CDFS的稳定工作范围减小，而对HPC的匹配状态影响较小。

Abstract:

Multiple bypasses and variable area valves perplex the aerodynamic connections between the compression components， i.e. fan， core-driven fan stage (CDFS) and high pressure compressor (HPC)， of a double bypass engine (DBE). Reasonably matching the components lays on the foundation of the design of a DBE compression system. To explore the design rules of DBE compression systems， the component matching principles of a custom-designed DBE compression system was analyzed in the present study by employing a versatile integrated compressor throughflow procedure. The baseline matching state and two throttling schemes， i.e. first bypass throttling and second bypass throttling， were investigated. For the DBE compression system considered in this paper， the throughflow calculation results show that the total pressure ratio of the compression system is reduced by 2% and the efficiency decreased by 0.002 for the spanwise mismatches in CDFS and HPC at baseline matching state. First bypass throttling remarkably affects the matching state of HPC first stage while having little effects on the spanwise matching state of subsequent stages and CDFS. Second bypass throttling substantially changes the inlet flow profiles of CDFS and cuts down the stable work range of CDFS while having little impacts on the matching state of HPC.