轴流压气机小流量状态转子叶尖泄漏涡三维紊流特性

3-D Turbulent Characteristics of the Tip Leakage Vortex inside an Axial Compressor Rotor Passage at a Low Mass-Flow Condition

用三维激光多普勒测速系统测量研究了低速大尺寸单级压气机在小流量状态下转子叶尖泄漏涡的三维紊流特性。结果表明 ,小流量状态下叶尖泄漏涡是引起压气机转子内尖部紊流脉动的主要因素之一 ,造成的高紊流区沿流向逐渐扩大 ,并较迅速地向通道中部和低叶高方向移动 ,紊流强度值随旋涡的增强而增大。在泄漏涡影响区域中 ,径向紊流强度水平最高 ,轴向和切向紊流强度水平相近 ,3个剪切应力中 ,轴向—径向最大 ,切向—径向次之 ,轴向—切向最小。在 80 %弦长附近 ,泄漏涡发生破裂 ,导致更强、更大范围的紊流脉动。受角区旋涡发展的影响 ,后半个通道内叶尖吸力面角区在较大范围内紊流脉动强 ,剪切应力大。

Three-dimensional turbulent characteristics of the tip leakage vortex inside an axial-flow compressor rotor passage were studied using a 3-Component Laser Doppler Velocimetry.The measurements were conducted in a low-speed large-scale compressor at a low mass-flow condition.The flow was surveyed across the entire passage at fifteen axial locations (leading edge to trailing edge) and twelve radial locations (0.985 to 0.700 spans).The measurement results indicated that strong interactions of the tip leakage vortex and the annulus-wall boundary layer produce high turbulence.The region of high turbulence develops with the leakage vortex.The radial turbulence intensity is the largest of the three components,and the axial-radial Reynolds stress is the largest of the three shear stresses.Breakdown of the leakage vortex happens at about 80% axial chord and makes the downstream flow more turbulent in the larger region.The corner vortex contributes to the high turbulence level at the corner of the tip suction surface.