The Migration of Corner Separation Flow in Multi-Channel Compressor Cascades at High Attack Angle

摘要

The corner stall is known as a thorny problem for further increase of aerodynamic load and stability of compressors because of the notable instability separation flow in 3D space. The unsteady flow field in 6 channel rectangle cascades with clearance is studied by numerical simulation of RANS with SST turbulence model and γ-Reθ transition model. The analysis of results shows that with the increase of attack angle, the low energy fluid in the corner region chooses to move along spanwise direction firstly and fluctuates periodically. At critical angle of attack, the low energy fluid adapts to the too large flow drag by breaking through the limitation of local space in identified cascade corner and propagates as a way of unstable stall cells at lateral speed of 27.47% of inlet velocity.