Computational analysis of vortices near casing in a transonic axial compressor rotor. (February 2019)

• Record Type: Journal Article
• Authors: Wu, Yanhui; An, Guangyao; Chen, Zhiyang; Wang, Bo
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 233:Number 2(2019)
• Page Start: 710
• Page End: 724
• Publication Date: 2019-02
• Subjects: Eigenvector method -- Lambda 2 method -- tip leakage vortex -- transonic axial flow compressor rotor -- vortex breakdown; Aeronautics -- Periodicals; Astronautics -- Periodicals; Airplanes -- Design and construction -- Periodicals; Aerospace industries -- Periodicals; 629.1
• DOI: 10.1177/0954410017740922
• Languages: English
• ISSNs: 0954-4100

Abstract

Complicated flowfields near casing in a transonic axial flow compressor rotor have been numerically investigated in this paper. Two vortex identification methods, namely the Eigenvector Method and Lambda 2 Method, are introduced as important tools for the graphical representation of the concentrated vortices arising from tip leakage flow and blade boundary layer separation. The analysis of the numerical results reveals that multiple tip vortices whose development are dependent on the variation of shock wave configuration are observed at conditions around the peak efficiency point. However, with the decrease of the massflow rate, only the well-known tip leakage vortex and the second tip vortex are left in the tip region due to the disappearance of the second shock wave. Then when the massflow rate further decreases to the stall limit, an deceleration flow region emerges downstream of the shock wave due to an increasing interaction between the first shock wave and the well-known tip leakage vortex. The tip leakage vortex further experiences a bubble-type and then spiral-type breakdown at near stall flow conditions. In addition, the validity of the two vortex identification methods is also discussed in this paper. It is found that both methods are able to identify and accentuate the concentrated streamwise vortices near casing when a vortex is not disrupted. However, if the vortex breakdown occurs, only Eigenvector Method can describe the breakdown region in a deep view.