组合抽吸对扇形扩压叶栅性能影响的数值研究

Numerical study on the effect of combined suction on the performance of fan-shaped diffuser cascade

为避免压气机失速的发生,采用数值仿真方法,对跨音速压气机DMU-37静子扇形叶栅展开研究,分析在叶栅端壁与吸力面同时进行附面层抽吸时对该扇形叶栅性能的影响,同时讨论了改变总抽吸质量流量的影响。结果表明,端壁区域的损失会随着抽吸流量的增加逐渐减小,上、下端壁三维角区回流强度减弱;通流能力随着抽吸流量的增加而逐渐提升,叶栅内主要涡结构逐渐向端壁迁移;随着抽吸流量的增加,流入抽吸腔的流体速度增大,附面层抽吸能力增强,当抽吸流量为进口流量的2%时,总压损失系数较未抽吸时降低49.07%;在固定抽吸流量率条件下,双侧端壁抽吸与吸力面组合抽吸可让叶栅气动参数更加均匀,推迟附面层分离。分析组合式附面层抽吸对扇形叶栅角区与型面分离的控制效果,对组合附面层抽吸机理做进一步探究,可为附面层抽吸在压气机中的应用、吸附式压气机的设计提供理论依据与设计准则。

To avoid compressor stall, a numerical simulation method was used to investigate the fan-shaped cascade of the transonic compressor DMU-37 stator blade, and analyze the performance of the fan cascade when the end wall of the cascade and the suction surface were simultaneously suctioned by the boundary layer, as well as discussing the effect of changing the total suction mass flow rate. It is concluded that the loss in the end wall area will gradually decrease with the increase of the suction flow, and the backflow strength in the three-dimensional corner area of the upper and lower end walls will be weakened. The flow capacity increases gradually with the increase of suction flow, and the main vortex structure in the cascade gradually migrates to the end wall. As the suction flow rate increases, the velocity of the fluid flowing into the suction chamber increases and the suction capacity of the attached surfaces layer increases. When the suction mass flow rate is 2% of the inlet flow, the total pressure loss coefficient is reduced by 49.07% compared with that without suction. Under the condition of a fixed suction flow rate, the combined suction of double-sided end wall suction and suction surface can make the aerodynamic parameters of the cascade more uniform and delay the separation of the boundary layer. To analyze the effect of the combined surface layer suction on the separation of the angular area of the fan blade cascade from the profile, and to further investigate the mechanism of combined surface layer suction can provide a theoretical basis and design criteria for the application of surface layer suction in compressors and the design of adsorption compressors.