压气机叶顶间隙变化规律及对气动性能的影响

Change Law of Tip Clearance and Its Influence on Aerodynamic Performance of Compressor

以大涵道比涡扇发动机系列的十级高压压气机为研究对象,在压气机部件、核心机及整机平台上详细开展了压气机叶顶间隙变化规律及其对气动性能影响的试验研究,同时结合叶顶间隙对跨音级、高亚音级和低亚音级的仿真验证,得到了压气机不同级对叶顶间隙的性能敏感区,进而揭示了叶顶间隙影响多级压气机整机性能的机理。结果表明:不同尺寸的压气机叶顶间隙变化规律具有一致性,经验证主要和离心力及温度场相关。间隙增大后压气机设计转速下的流量压比特性和流量效率特性均整体下降,尤其后面级间隙对气动性能有显著影响。随着叶顶间隙的增大,压气机的跨音级因叶片较长使得相对叶顶间隙较小,未出现效率突降的情况,但是后面亚音级做功能力明显降低,间隙影响主要集中在后面级即亚音级,使得压气机典型工况的效率和裕度均有所下降。

Several ten-stages-compressor of a high bypass ratio turbofan engine was used as the research object,the change law of tip clearance and its effects on aerodynamic performance and stable boundary of the compressor were investigated based on a high speed compressor component,core engine and complete engine test facility.The mechanism and the sensitive area of tip clearance effect on the overall performance and each stage performance of multistage compressors was revealed by detailed simulation results of transonic and subsonic stage performance.The results show that the clearance change law of compressors of different sizes is consistent,which is mainly related to centrifugal force and temperature filed.Flow-pressure ratio and flow-efficiency characteristics of the compressor at design rotational speed Indicate a feature of whole reduction while the clearance increases,and the clearance has more impact on the back subsonic stage.With the increase of the tip clearance,the efficiency of the front transonic stages of the compressor does not decrease for the small ratio of clearance to the big blade height,but the work capacity of the back subsonic stage decreases obviously,and the influence of the clearance mainly concentrates on the back subsonic stage,which makes the compressor efficiency and stall margin droop.