摘要
采用数值计算和实验研究相结合的方法,研究了跨音速转子叶顶泄漏流与主流交界面轴向位置随流量的变化规律和机制。该跨音转子是美国圣母大学一级半跨音速压气机转子。研究发现机匣壁面脉线分布能够定性反映壁面轴向剪切应力分布,可用来识别叶顶泄漏流与主流的交界面位置。通过机匣壁面的脉线分布,可以看出机匣壁面存在两条零剪切应力线。第一条零剪切应力线表示来流与叶顶泄漏流之间交界面的时间和周向平均轴向位置,在小流量工况下交界面靠近顶部叶片的前缘。计算和实验结果都表明,随着质量流量的减小,叶顶泄漏流与主流交界面的轴向位置不断向叶片前缘移动。在近失速点,交界面到达叶片前缘,泄漏流即将溢出。泄漏流与主流的轴向动量比随流量减小不断增大的变化规律进一步说明,间隙区域泄漏流与主流的轴向动量平衡是导致交界面不断前移直至溢出的内在机制。
Movement of the interface between tip leakage flow and incoming main flow in tip region and its mechanism are investigated with numerical simulation and experiment.The transonic rotor investigated in this paper is the rotor of one and a half stage compressor at University of Notre Dame. It is found that the interface between tip leakage flow and incoming main flow can be identified with axial shear stress distribution,which can be qualitatively reflected by the streaking lines at casing.Streaking line distribution shows there are two zero-axial-stress lines on the casing.The first separation line is located near leading edge at operating point with small mass flow rate,which is time-and circumferential-averaged axial location of the interface.Numerical and experimental results show that time-and circumferential-averaged axial location of the interface moves forward to the leading edge of blade tip as mass flow rate decreases.At operating point near stall,the interface arrives at the leading edge.Variation of axial momentum ratio of tip leakage flow to incoming flow in tip region as a function of mass flow rate demonstrates that the axial momentum balance is the mechanism for the movement of the interface.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2011年第6期929-932,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.50736007)
国家重点基础研究发展规划(No.2007CB210104)
关键词
叶顶泄漏流/主流交界面
轴向剪切应力
跨音速压气机转子
Interface between tip leakage flow and main flow
axial shear stress
transonic compressor rotor
