基于马蹄涡前缘吸气控制的压气机叶栅流动机理

To explore the source flow control method for the corner separation, this paper takes the NACA65 cascade as the research object and applies the blade leading edge endwall suction technology to control the horseshoe vortex with the numerical simulation method. Combined with topology analysis, the three-dimensional flow field is accurately reconstructed and the control mechanism of the leading edge endwall suction is revealed to improve the cascade channel flow field performance. The results show that the leading edge endwall suction technology can effectively delay the formation of the horseshoe vortex and weaken its strength. Meanwhile, a pair of counter rotating vortices are formed at the end of the suction slit, which interacts with the passage vortex in the process of downstream development. By regulating horseshoe vortices, the suction lessens the thickness of the endwall boundary layer, inhibiting the formation of leading edge passage vortices and preventing surface separation caused by backflow. Because the leading edge and pressure side suction (EPS) directly acts on the pressure side leg of the horseshoe vortex, the passage vortex strength is further weakened, and the corner separation mode changes from closed separation to incomplete closed separation. Finally, the total pressure losses are compared at the outlet under the optimal suction coefficient. It is discovered that when the suction coefficient is 0.2%, the overall pressure loss at the EPS outflow section is decreased by 5.8%. At off-design situations, improved control performance can be attained by modifying the suction coefficient.