为了探究核心机驱动风扇级不同工作模式下转子叶尖流动结构和机理,对某核心机驱动风扇级转子流场进行了三维定常数值模拟,分析了单外涵模式和双外涵模式下工作点及近失速点转子叶尖流场结构特点,并研究了不同叶尖间隙对核心机驱动风扇级性能的影响。结果表明:单外涵模式与双外涵模式设计点叶尖泄漏涡起始位置不同;单外涵模式转子叶尖存在贯穿流道的正激波,双外涵模式该正激波消失;泄漏涡经过转子叶尖超声速区域会形成低速带;单外涵模式时泄漏涡经过正激波后发生扩散,并使正激波出现“缺口”;转子叶尖间隙大小对核心机驱动风扇级两种工作模式下的流量、压比和等熵效率影响均较小,间隙增大到一定程度后稳定裕度下降剧烈。
The rotor 3-D flow of a core driven fan stage is simulated to investigate the characters of flow structure and flow mechanism at different operation modes. Both single bypass mode and double bypass mode are analyzed at design operation points and near stall points. The performances of core driven fan stage with the different scales of rotor tip clearance are studied. The results show that the origins of the tip clearance vortex are different far single bypass mode and double bypass mode at design operation point. Normal shock wave occurs in the rotor passage at design operation point in single bypass mode, while in double bypass mode the normal shock wave vanishes. The tip clearance vortex presents a low-speed region in the supersonic areca Tip leakage vortex diffuses while it passes through the normal shock wave and makes the normal shock wave presents a gap. The tip clearance scales have a slight effect on mass flow rate, pressure ratio and isentropic efficiency, while the stability margin is sensitive to the large tip clearance.