Numerical Investigation on the Flow Mechanism of Multi-Peak Frequency Feature of Rotating Instability  

作　　者：WANG Hao WU Yadong YUE Shaoyuan WANG Yan'gang 

机构地区：[1]School of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China [2]School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Thermal Science》2021年第2期668-681,共14页热科学学报（英文版）

基　　金：The authors would like to acknowledge the supports of National Natural Science Foundation of China(Grant No.51906205);National Science and Technology Major Project(2017-Ⅱ-0009-0023).

摘　　要：In this paper,the rotating instability(RI)in an axial compressor has been investigated numerically in order to examine the capability of URANS method to simulate its typical characteristics of RI broadband humps with multi-peak frequencies(MPFs)and further to uncover the underlying flow mechanism.A full-annulus modeling solution has been adopted to fully capture the wide range of different length-scale flow disturbances that circumferentially propagating around the compressor rotor.During the transient computing process,long-term monitoring up to 50 revolutions has been carried out to achieve a fine frequency resolution,and that would be essential for resolving the MPFs with small frequency interval.It is shown that the MPFs feature of RI has been successfully captured by the full-annulus URANS approach,and also its frequency range and spectral feature agree well with the experimental results.Further,with a circumferential mode decomposition on the MPFs characteristics of RI,it has been found that the MPFs result from the interaction between long-and short-scale flow disturbances which circumferentially propagate around the compressor rotor near the clearance region.zDetailed examination on the numerical three dimensional flow field indicates that the short-scale disturbance is induced by the unsteady oscillation of tip clearance vortexes with inter-passage phase delay.The long-scale disturbance is caused by the mistuning of the wave number of the short-scale disturbance and the blade number within the whole annulus.

关 键 词：axial compressor rotating instability multiple frequency peaks URANS tip leakage vortex 

分 类 号：TK474.8[动力工程及工程热物理—动力机械及工程]