多级轴流压气机失速特性分析

Performance Analysis of Multistage Axial Compressor at Stall Conditions

为了对某九级低压压气机的低工况性能进行改进和优化,分析压气机在低工况下的特性是必要的。采用三维黏性数值模拟方法对非设计工况进行了计算,根据压气机在近失速状态下的级特性,详细分析了第一级、第二级和末级的流场特性。结果表明:第一级转子扩压负荷过大,顶部发生了突尖波失速,是造成压气机不稳定运行的主要原因,且使下游的进气条件变差,导致第二级叶片顶部发生流动分离;末级静子扩压负荷较大,静子通道涡造成的漩涡耗散损失使末级的绝热效率低下。

In order to improve and optimize the low-condition performance of a nine-stage axial low-compressor, analyzing its flow-field is prerequisite. A three-dimensional viscous numerical simulation was conducted to calculate the internal flow of the compressor at off-design condition. Based on the stage performance of the compressor, flow characteristic of the first stage, the second stage and the last stage was analyzed in detailed. The results show that, under high diffusion load, a spike precursor stall occurred at top of rotor of the first stage, which was the primary cause for the eompressor instability. At top of blades of the second stage flow separation took place because of the poor inlet condition. Passage vortex of stator of the last stage decreased the stage-isentropic efficiency.