System Identification Modeling and Unstable Behavior of the Dynamics of Flows within the Tip Region of an Axial Compressor Blade Passage  

作　　者：STERBENTZ Dane M. PRASAI Sujan HOFLE Mary M. WALTERS Thomas LIN Feng LI Ji-chao BOSWORTH Ken SCHOEN Marco P. 

机构地区：[1]Idaho State University, Measurement and Control Engineering Research Center [2]Institute of Engineering Thermophysics, Chinese Academy of Sciences

出　　处：《Journal of Thermal Science》2016年第2期109-116,共8页热科学学报（英文版）

基　　金：supported by a generous grant from the National Natural Science Foundation of China on project No.51306178

摘　　要：In recent years, the correlation coefficient of pressure data from the same blade passage in an axial compressor unit has been used to characterize the state of flow in the blade passage. In addition, the correlation coefficient has been successfully used as an indicator for active control action using air injection. In this work, the correlation coefficient approach is extended to incorporate system identification algorithms in order to extract a mathematical model of the dynamics of the flows within a blade passage. The dynamics analyzed in this research focus on the flow streams and pressure along the rotor blades as well as on the unsteady tip leakage flow from the rotor tip gaps. The system identification results are used to construct a root locus plot for different flow coefficients, starting far away from stall to near stall conditions. As the compressor moves closer to stall, the poles of the identified models move towards the imaginary axis of the complex plane, indicating an impending instability. System frequency data is captured using the proposed correlation based system identification approach. Additionally, an oscillatory tip leakage flow is observed at a flow coefficient away from stall and how this oscillation changes as the compressor approaches stall is an interesting result of this research. Comparative research is analyzed to determine why the oscillatory flow behavior occurs at a specific sensor location within the tip region of the rotor blade.

关 键 词：axial compressor correlation coefficient oscillatory behavior system identification 

分 类 号：TH453[机械工程—机械制造及自动化]