| Citation: | HUANG Lin, FU Chao. Study on the mechanism of flow loss in the tip region of turbine rotors[J]. Journal of Aerospace Power, 2025, 40（11）：20230777 doi: 10.13224/j.cnki.jasp.20230777
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An in-house detached eddy simulation program was employed to simulate the flow in the turbine rotor blade tip region, and high-precision flow field data were obtained, so as to comprehensively investigate the physical process of local aerodynamic loss in this region. The local mixing loss caused by mixing between tip leakage and mainstream flows in the tip clearance region was quantitatively assessed using entropy production analysis. Additionally, the mechanisms and contributions of the time-averaged flow field and fluctuating flow field to the entropy production rate were explored. The results demonstrated that both time-averaged and fluctuating entropy productions were important sources of the mixing loss. Time-averaged entropy production dominated upstream losses, whereas fluctuating entropy production dominated downstream losses. The generation and spatial distribution of the time-averaged entropy production were determined by the normal velocity profile of the tip leakage jet. Time-averaged entropy production varied in magnitude and spatial distribution due to differences in shear strength and the thickness of the tip leakage flow boundary layers in the upstream and downstream locations. The generation of the fluctuating entropy production was dominated by the amplification term caused by the time-averaged strain rate tensor and the pressure Hessian term caused by the vortical structures in the fluctuating flow field.
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