上游离散气膜孔型对静叶收敛端壁气热性能和气膜冷却效率影响的研究  

Effects of upstream discrete film hole shape on aerothermal performance and film cooling effectiveness of turbine vane convergent endwall

作　　者：张昊 白波 李志刚[1] 李军[1] ZHANG Hao;BAI Bo;LI Zhigang;LI Jun(Institute of Turbomachinery,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学叶轮机械研究所,陕西西安710049

出　　处：《推进技术》2025年第3期150-161,共12页Journal of Propulsion Technology

基　　金：国家科技重大专项(J2019-Ⅱ-0011-0031);国家自然科学基金(51936008)

摘　　要：气膜冷却孔型影响冷气射流型态以及与端壁二次流的相互作用,进而影响涡轮静叶造型端壁的传热冷却特性。采用数值求解三维Reynolds-Averaged Navier-Stokes(RANS)方程和Realizable k-ε湍流模型的方法研究了上游圆形孔和扇形孔对涡轮静叶收敛端壁气热性能的影响特性,分析了6种质量流量比(MFR)下圆形孔和扇形孔的涡轮静叶端壁的热负荷分布、绝热气膜冷却效率、端壁二次流,以及叶片压力面侧的二次冷却效果(风影冷却)。研究表明:相比圆形孔,扇形孔能有效降低叶片肩部和气膜孔尾迹的端壁热负荷;同时,扇形孔可以显著增加端壁气膜覆盖范围和绝热气膜冷却效率,特别是在叶片前缘、叶栅通道上游以及叶片两侧。扇形孔消除了圆形孔出口冷气的流动分离现象进而降低了叶栅通道上游端壁温度。气膜冷气与马蹄涡形成前缘滞止涡,扇形孔的前缘滞止涡范围更大,提高了叶片前缘以及紧贴叶片两侧的气膜冷却效果和面积。在MFR=2.3%时,扇形孔对端壁绝热气膜冷却效率的增强效果最显著,面平均值相比圆形孔增加约40%。MFR=2.7%时扇形孔风影冷却覆盖面积最大,相比圆形孔减小约20%,但叶片近端壁表面温度下降15 K。相比于圆形孔,扇形气膜孔能够提高收敛型端壁冷却效率,但同时需要增加冷却气体质量流量比。The film hole shape influences the flow pattern of the coolant jet flow and interaction with the secondary flow,which in turn affects the heat transfer and film cooling layout of turbine vane convergent endwall.The effects of the upstream film hole shape(circular holes and fan-shaped holes)on the aerothermal performance of the turbine vane convergent endwall was numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes(RANS)and Realizable k-εturbulence model solutions.The endwall thermal load distribution,adiabatic film cooling effectiveness and endwall secondary flow field for circular film hole and fan-shaped film hole were calculated and analyzed at six different mass flow ratios(MFR).Furthermore,the phantom cooling of the vane pressure side surface was also compared.The obtained results showed that compared with circular holes,fan-shaped holes effectively reduced the endwall thermal load at the region of vane shoulder,jet wake after film holes.Fan-shaped holes significantly increased the coverage area and the adiabatic effectiveness of film cooling,especially at the regions of vane leading edge,vane pressure and suction side and upstream of the vane cascade channel.The fan-shaped holes eliminated the flow separation phenomenon of the circular holes’outflow and re⁃duced the endwall temperature.The film cooling was mixed with horseshoe vortex and formed a stagnant vortex at the vane leading edge.The stagnant vortex of fan-shaped holes was larger,and it steeply improved film cooling ef⁃fects and area at the leading edge and both near side of the vane.At MFR=2.3%,the fan-shaped holes enhanced endwall film cooling efficiency the most(the surface-averaged value increased about 40%compared with the cir⁃cular hole).At MFR=2.7%,the phantom cooling coverage of the fan-shaped hole was the largest,which was about 20%smaller than that of the circular hole,and the vane’s surface temperature decreased by 15 K.Com⁃pare to the circular film hole,fan-shaped film holes can effectively improve

关 键 词：涡轮静叶 收敛型端壁 气膜孔型 气膜冷却 风影冷却 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程] TK474.7[动力工程及工程热物理—动力机械及工程]