KONG Xiaozhi
,
HUANG Tianshuo
,
LIU Yuxin
,
LU Huawei
,
WANG Long
. Influence of Cavity Leakage flow on Corner Separation in a Shrouded Stator Cascade[J]. 热科学学报, 2023
, 32(1)
: 351
-365
.
DOI: 10.1007/s11630-022-1705-7
The impacts of the cavity leakage flow on the shrouded stator aerodynamic performance were investigated by modelling the annular cascade mainstream with the seal cavity flow path based on the validated numerical method. Meanwhile, the interactions between the cavity leakage and the mainstream were also determined in the current study. The development of hub corner separation under the action of leakage was discussed and the total pressure loss coefficient as well as the entropy-based loss coefficient was employed to evaluate the performance changes at different seal clearances and cavity rotational speeds. The results show that the cavity leakage flow induces a new vortex near the blade leading edge and plays an important role in the development of passage vortex and the size of concentrated shedding vortex. By increasing the seal clearance with more cavity leakage flow rate, an increase in the pitchwise extent of the separation region under 15% span is significant and the total pressure loss in the separation core increases. In addition, with the increase of cavity rotating speed, the starting point of corner separation moves backward, reducing the size and depth of the hub corner separation. The mainstream loss reduction in combination with the entropy increase in the seal cavity causes the entropy-based loss coefficient to perform a trend of decreasing first and then increasing with the cavity speed.
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