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Tip leakage flow (TLF) is a dominant source of aerodynamic loss in high-subsonic compressors. In this study, delayed detached eddy simulation is employed to investigate the control of TLF using end wall distributed pulsed suction in a NACA65-K48 compressor cascade subject to upstream wake disturbances, providing an improved numerical basis for resolving vortex cores and unsteady flow features. Dynamic mode decomposition (DMD) is further applied to decouple the multi-frequency interference and elucidate the underlying control mechanisms. The results indicate that upstream wakes significantly enlarge the circumferential and spanwise extent of TLF, while their unsteady characteristics can be leveraged to enhance control effectiveness. Crucially, the analysis reveals that the spatial placement of the suction holes dictates the primary control authority, whereas the pulsed frequency serves as a secondary fine-tuning mechanism. Spatially, suction holes arranged along the tip leakage vortex (TLV) trajectory prove significantly more effective than those placed along the camber line, particularly near the vortex roll-up region. Temporally, for single-hole suction, a resonance effect is observed at the dominant frequency of the TLV (1F+). In distributed configurations, applying a sub-harmonic frequency at the downstream hole aligns with the evolved vortex timescale, with the 1 F++0.5 F+ scheme reducing the total pressure loss coefficient by approximately 6.65%. DMD analysis confirms that distributed suction effectively suppresses TLF energy fluctuations across the fundamental frequency and its higher harmonics (1 F+, 2 F+, and 3 F+), weakens the vortex cores, and mitigates breakdown-induced losses. These findings provide new insight into the interaction mechanisms of distributed pulsed suction and offer guidance for its application in advanced compressors under realistic inflow conditions.
Zhang et al. (Fri,) studied this question.