面向气膜冷效提升的涡轮叶栅全端壁非轴对称造型设计优化

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中图分类号：TK47 文献标志码：A

DOI： 0.765/xjtuxb0508007 文章编号：053-987X（05）08-0064-

Optimization of Full-Endwall Non-Axisymmetric Contouring Design for Turbine Cascades Aimed at Enhancing Film Cooling Effectiveness

TAO Zhi1，WANG Jie1'²，LI Bolin¹，YAN Yifei¹，SONG Liming¹，LI Jun1 （1. School of Energy and Power Engineering，Xi'an Jiaotong University，Xi'an 71oo49，China; 2.TaiHangLaboratory，Chengdu 6l0299，China）

Abstract： To explore the enhancement mechanism of non-axisymmetric endwall design on both endwall sealing coolant and discrete-hole film cooling effectiveness，a full-endwall non-axisymmetric contouring method based on periodic non uniform rational B-spline surfaces is proposed， overcoming geometric constraints in traditional approaches for the upstream region of cascade leading edges. A numerical simulation model of turbine cascades incorporating endwall slots and discrete film cooling holes is established and validated against experimental data. Using endwall-averaged film cooling effectiveness as the objective function，a global optimization algorithm based on Kriging surrogate modeling is employed for endwall design optimization. Simulation results indicate that， compared to the original axisymmetric endwall，the average film cooling eficiency of the nonaxisymmetric endwall increases by 9.36% ， 10.68% ，and 14.76% at three different blowing ratios， while the total pressure loss coefficient at the cascade exit remains largely unchanged. The nonaxisymmetric endwall design not only alters the pressure distribution in the end region but also significantly reduces the static pressure near the blade leading edge and the lateral pressure gradient at the inlet position of the cascade channel. This allows the cooling jet to achieve a broader film coverage area near the blade leading edge and channel inlet，while also weakening the lateral secondary flow in the end region， thus suppressing its entrainment efect on the cooling jet and enhancing the film coverage on the endwall near the pressure side of the blade. This research provides theoretical foundations and technical references for cooling protection of modern turbine endwalls under high thermal-mechanical loads.

Keywords： non-axisymmetric endwall； design optimization； discrete film holes； film cooling;blowing ratio

随着涡轮进口温度的逐年攀升，涡轮叶片端区面临的热负荷也不断增大[]。（剩余16912字）