轴向间距对压气机通道堵塞及总性能的影响

为了研究转静子叶片排之间的轴向间距对压气机内部流动堵塞及气动性能的影响,选取某单级轴流压气机为研究对象,采用多通道非定常数值计算方法对其5种不同轴向间距下的内部流场进行了全三维数值模拟。结果表明:在每一种轴向间距下,当压气机节流至某一工况之后,压气机通道内的流动堵塞区主要集中在转子叶顶间隙区域和动叶吸力面尾缘附近以及静叶吸力面轮毂角区内;在同一流量下,随着轴向间距的减小,转子叶根吸力面尾缘处的流动堵塞区有所扩大,但转子叶顶间隙区域及静叶吸力面轮毂角区内的流动堵塞区体积却不断减小,压气机通道内回流区的总体积也随之减小,其结果是压气机的静压升能力和流动稳定性增强且效率增大。通过进一步研究发现:在同一流量下,当轴向间距减小时,转子叶顶间隙区域内的主流轴向动量增大且泄漏流的轴向动量减小,其结果是转子叶顶间隙区域内流动堵塞区的体积减小。

Influence of axial gap on compressor passage blockage and aerodynamic performance

In order to investigate the influence of the axial gap between the rotor and the stator on the flow blockage in a single-stage axial flow compressor and its aerodynamic performance, the unsteady three-dimensional multi-passage numerical simulations were carried out to investigate the flow fields of the compressor with five different rotor/stator gaps. The computational results show that in any case of the five different rotor/stator gaps, when the compressor is operating below the critical mass flow, the flow blockage zones are mainly located near the trailing edge of the rotor blade suction surface and in the rotor blade tip clearance region as well as in the hub and suction surface corner region of the stator. Moreover, with the same mass flow, when reducing the axial gap between the rotor and the stator, the flow blockage near the trailing edge of the rotor blade root suction surface becomes larger, however, the volume of flow blockage zone decreases in the rotor blade tip clearance region as well as in the hub and suction surface corner region of the stator, and thus the total volume of the flow blockage zones in the compressor becomes smaller. This is followed by an increase of the static pressure rise capability and the stable operating range as well as the adiabatic efficiency of the compressor. The research shows that with the same mass flow, as the axial gap decreases, the axial momentum of the main flow in the rotor blade tip clearance region increases, and that of the rotor tip leakage flow reduces. The result is that the volume of flow blockage zone in the rotor blade tip clearance region decreases.