Session: 40-03 Compressor Flow and Interaction Effects

Submission Number: 176359

Spatio-Temporal Evolution of Tip Leakage Flow in a Low-Speed Axial Compressor 

The tip leakage flow (TLF) in axial compressors is a critical phenomenon governing stability, efficiency, and noise generation. While its steady-state structure is broadly understood, its inherent unsteady nature and spatio-temporal evolution under various operating conditions remain areas of active research. This investigation numerically characterizes the dynamic behavior of the TLF in a low-speed axial compressor rotor using delayed detached eddy simulation (DDES). By analyzing the snapshot near-tip flow field data at multiple operating points from peak efficiency to near-stall, the analysis reveals a complex interplay between the main tip leakage vortex, the secondary tip leakage vortex, and the shedding wake of the trailing edge. Spatially, the trajectory and growth of the tip leakage vortex core are mapped, showing significant contraction and increased vorticity as mass flow reduces. Temporally, the onset of a low-frequency, pre-stall ‘vortex wandering’ is identified and quantified, characterized by periodic oscillations in the vortex core position and strength. This unsteadiness is shown to be a precursor to rotating stall inception, initiating at approximately 85% of the stable mass flow range. The findings provide a comprehensive, time-accurate dataset and elucidate the critical dynamic mechanisms by which the evolving tip leakage flow triggers instability, offering valuable insights for predicting and controlling stall margins in compressor design.

Presenting Author: Xiao He Shanghai Jiao Tong University

Presenting Author Biography: Xiao He is an Associate Professor at the School of Aeronautics and Astronautics, Shanghai Jiao Tong University. His research focuses on data-enabled design and analysis of high-quality turbomachines.

Authors:

Xiao He Shanghai Jiao Tong University
Fanzhou Zhao Imperial College London
Mehdi Vahdati Universidad Politecnica de Madrid