高比转速跨声离心/斜流压气机流动特点分析

  目的  压气机是燃气轮机的核心部件之一，它直接决定了燃气轮机性能的优劣。斜流压气机是介于轴流压气机和离心压气机之间的一种形式，兼具离心压气机高压比和轴流压气机流通能力强的优点。  方法  采用一套通用于轴流、离心和斜流压气机的S2流面气动设计和任意中弧线叶片造型的程序，对某斜流+轴流组合式多级压气机进行气动设计，研究确定压气机的流道形式、环量分布，并对其进行叶片造型。在设计时，结合商用数值模拟软件对该组合式压气机进行流场数值分析。  结果  结果表明，该斜流轴流组合式压气机的各项参数均满足设计指标，压气机两级总压比和绝热效率分别达到4.3和88%。  结论  tt 该斜流轴流组合式的压气机设计有如下难度：一是斜流级静子进口处马赫数较高，在斜流静子中控制气流流动的难度较大；二是为控制气流在斜流静子中的分离，斜流级静子弯度较小，导致轴流级处于较大的负攻角状态，斜流与轴流的级间匹配难度较大。

Mixed-flow compressor stage design and test results with a pressure ratio of 3:1

  Objectives  The performance of a gas turbine engine can be determined by the performance of the compressor. As one of the core components of a gas turbine engine, the design of the compressor is of critical importance in the design of the engine overall.  Methods  A mixed flow compressor, a compressor between the axial flow compressor and centrifugal compressor, offers the high flow capacity and high efficiency of axial compressors, as well as the high pressure rate of centrifugal compressors. The design of a mixed-axial flow compressor and the choice of design parameters are based on the results of the S2 through flow aerodynamic design program and the general arbitrary curved blade design method for axial, centrifugal/mixed compressors. Numerical simulation software is used to simulate the 3D flow field of the mixed flow compressor.  Results  The results show that the performance of a multistage mixed-axial flow compressor reaches the design target, achieving a pressure ratio of 4.3 and an adiabatic efficiency of 88%.  Conclusions  ttDespite these results, the remaining difficulties in design of such a compressor are as follows:1. the flow in the stator at the mixed flow stage is difficult to control due to the high inlet Mach number; and 2. the matching of flow incidences between the axial-flow stage and mixed-flow stage still requires a large amount of work.