离散气膜孔与间隙冷气掺混作用下燃气透平叶栅端壁气动特性研究

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关键词：燃气透平；端壁；多源冷却结构；二次流；气动性能中图分类号：TK474.7文献标志码：ADOI：10.7652/xjtuxb202509015 文章编号：0253-987X（2025）09-0152-13

Study on Aerodynamic Characteristics of Gas Turbine Cascade Endwall Under the Interaction of Discrete Film Cooling Holes and Gap Cooling Air Mixing

ZHANG Kaiyuan，LI Zhiyu，BAI Bo，LI Zhigang，LIJun （Institute of Turbomachinery，Xi'anJiaotongUniversity，Xi'an 7loo49，China）

Abstract： To address the unclear mechanisms of jet interaction and complex mixing between multi-source cooling structures and secondary flows in the endwall region of gas turbines， cascade wind tunnel experiments and numerical simulations are conducted to investigate the mixing characteristics of discrete film cooling holes and gap jets，as well as their impact on the aerodynamic performance of cascade endwalls under three cascade exit Mach numbers （O.2，0.3， and O.4）and three cooling air blowing ratios （1.5，2.O，and 2.5）. The results demonstrate that increasing aerodynamic loading on the cascade leads to a stronger tendency for gap cooling air to migrate downstream and for cooling air from film holes near the gap to flow out. The secondary flow significantly affects the accumulation of cooling air in the passage vortices and near the endwall region， leading to increased aerodynamic losses. At low Mach numbers （O.2），an increase in the cooling air blowing ratio enhances the tendency for upstream gap jets and pressureside horseshoe vortices to detach. The passage vortex loss area expands towards the pressure side and the near-endwall region，with an average total pressure loss coeficient increasing by 0.15% ： At high blowing ratios，gap jets can be drawn in by the horseshoe vortex，reducing the attachment effect in the area adjacent to the blade shoulder. At high Mach numbers （O.3 and 0.4），the influence of the horseshoe vortex on the pressure side is more significant，and the detachment point advances， significantly increasing the area of the low-pressure region downstream of the gap. The average total pressure loss coefficient in the passage vortex area increases by 0.1% to 0.16% with the increasing blowing ratio. The coverage area of the cooling air from the film holes near the gap is small， suggesting that the design should increase the distance from the gap and adjust the flow rate of the film holes to prevent detachment in the gap region.

Keywords： gas turbine; endwall； multiple cooling structure; secondary flow; aerodynamic performance

为了进一步提高燃气轮机的效率及推重比，需不断提高燃气透平的气动负荷及热负荷[1]。（剩余16191字）