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.
KONG Xiaozhi
,
HUANG Tianshuo
,
LIU Yuxin
,
LU Huawei
,
WANG Long
. Influence of Cavity Leakage flow on Corner Separation in a Shrouded Stator Cascade[J]. Journal of Thermal Science, 2023
, 32(1)
: 351
-365
.
DOI: 10.1007/s11630-022-1705-7
[1] Cao Z., Zhang X., Zhang F., et al., Tip leakage vortex and its breakdown mechanism in aspirated compressor cascades designed with conventional method and curvature induced pressure recovery concept. Aerospace Science and Technology, 2021, 113(6): 106692.
[2] Bayley F.J., Childs P., Bayley F.J., et al., Air temperature rises in compressor and turbine stator wells. ASME Paper, 94-GT-185, 1994.
[3] Kim S., Kim K., Son C., Three-dimensional unsteady simulation of a multistage axial compressor with labyrinth seals and its effects on overall performance and flow characteristics. Aerospace Science and Technology, 2019, 86(3): 683–693.
[4] Wellborn S.R., Details of axial-compressor shrouded stator cavity flows. ASME Paper, 2001-GT-0495, 2001.
[5] Marty J., Aupoix B., Interaction of shrouded stator flow and main flow and its influence on performances of a three-stage high pressure compressor. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2012, 226(4): 489–500.
[6] Chen M., Xie W., Wang H., Numerical investigation of stator cavity leakage influence to a compressor performance. Journal of Aerospace Power, 2014, 29(11): 2543–2549.
[7] Kong X., Liu Y., Lu H., et al., Performance analysis of inter-stage leakage flows at rotating conditions in an axial compressor. Journal of Thermal Science, 2020, 29(6): 1558–1568.
[8] Wellborn S.R., Okiishi T.H., The influence of shrouded stator cavity flows on multistage compressor performance. Journal of Turbomachinery, 1999, 121(3): 486–497.
[9] Kato D., Yamagami M., Tsuchiya N., et al., The influence of shrouded stator cavity flows on the aerodynamic performance of a high-speed multistage axial-flow compressor. ASME Paper, GT2011-46300, 2011.
[10] Flores D., Seume J.R., Selecting cavity geometries for improving the aerodynamic performance of an axial compressor. ASME Paper, GT2014-25328, 2014.
[11] Ma W., Lu K., Gu C., Compressor stator seal cavity geometry optimization and flow analysis. Journal of Engineering Thermophysics, 2009, 30(8): 1288–1290.
[12] Meng D., Xing L., Jian L., Influence of shrouded stator cavity flow on compressor stator performance. Aeroengine, 2013, 39(6): 31–42.
[13] Demargne A.A.J., Longley J.P., The aerodynamic interaction of stator shroud leakage and mainstream flows in compressors. ASME Paper, 2000-GT-570, 2000.
[14] Sohn D.W., Kim T., Song S.J., Influence of the leakage flow tangential velocity on the loss generation and leakage flow kinematics in shrouded axial compressor cascades. ASME Paper, GT2006-90979, 2006.
[15] Kim J.W., Lee J.S., Song S.J., et al., The impact of leakage flow tangential velocity on secondary losses in a shrouded compressor cascade. ASME Paper, GT2012-69217, 2012.
[16] Heidegger N., Hall E., Delaney R., Parameterized study of high-speed compressor seal cavity flow. AIAA paper, 96-2087, 1996.
[17] Yoon S., Selmeier R., Cargill P., et al., Effects of the stator hub configuration and stage design parameters on aerodynamic loss in axial compressors. Journal of Turbomachinery, 2015, 137(9): 091001.
[18] Cao Z., Gao X., Zhang X., et al., Influence of endwall air injection with discrete holes on corner separation of a compressor cascade. Journal of Thermal Science, 2021, 30(8): 1684–1704.
[19] Lu H., Yang Y., Guo S., et al., Control of corner separation via dimpled surface for a highly loaded compressor cascade under different inlet Mach number. Aerospace Science and Technology, 2019, 85(2): 48–60.
