Effect of Streamwise Micro-Rib Film Cooling Arrangements on Heat Transfer and Cooling Performance of Cavity Turbine Blade Tips

doi:10.12096/j.2096-4528.pgt.260113

Abstract

Abstract:

Objectives To enhance the heat transfer and cooling performance of blade tips and explore how curved micro-ribs induce cooling air flow and affect heat transfer performance, this study uses a numerical solution of three-dimensional Reynolds averaged Navier-Stokes (RANS) equation and standard k-ω turbulence models. The effects of streamwise micro-rib film cooling arrangements on heat transfer and cooling performance of cavity turbine blade tips are analyzed. Methods Based on the cavity blade tip of the first stage in GE-E3 high-pressure turbine, and following previous experience, a film cooling arrangement (case 1) is designed with large-diameter film holes at the leading and trailing edges, and two small-diameter film holes near the pressure side at the mid-chord region. Then, two additional small-diameter film holes are added near suction side at the mid-chord region where cooling air is scarce, and four mid-chord film holes are arranged at three positions to investigate the effect of hole position. For these three cooling arrangements, a curved micro-rib with 30% arc length is added to explore the effect of rib structure. Results Compared to case 1, placing the micro-rib at the leading edge of the cavity reduces blade tip leakage flow by 0.9% and total pressure loss at the outlet cross-section of flow passage by 0.5%. Positioning the micro-rib near the trailing edge results in an 8% reduction in blade tip heat transfer coefficient, and a 16% reduction when the micro-rib surface is excluded. Additionally, the streamwise micro-rib film cooling arrangement at this position achieves a film cooling effectiveness of 0.43 and optimal cooling uniformity. Conclusions The research findings can provide valuable references for the coupled design of high-performance blade tip structures in gas turbines; Reynolds averaged Navier-Stokes equation

Key words: gas turbine, streamwise micro-rib, cavity blade tip, heat transfer coefficient, film cooling effectiveness, cooling performance, Reynolds averaged Navier-Stokes (RANS) equation

CLC Number:

TK 14

Shihan LI, Bo BAI, Guoqiang CHENG, Chengtian XU, Xianglin KONG, Zhigang LI, Jun LI. Effect of Streamwise Micro-Rib Film Cooling Arrangements on Heat Transfer and Cooling Performance of Cavity Turbine Blade Tips[J]. Power Generation Technology, 2026, 47(1): 145-156.

Figures/Tables 17

Tab. 1 Geometric parameters of first stage in GE-E3 turbine

参数	数值
静叶数/个	46
动叶数/个	76
动叶高度H/mm	42.28
轴向弦长C_a/mm	28
叶顶间隙S/mm	0.42
凹槽深度h_s/mm	0.8
凹槽宽度T/mm	0.6

Fig. 1 Model of computational domain

Fig. 2 Geometric model of blade tip structure

Tab. 2 Computational boundary conditions

项目	边界条件	数值
进口	总压p_total，0/kPa	344.74
	总温T_total，0/K	712
	入流角 $α 0$ /( $°$ )	0
	湍流强度T_u/%	10
出口	静压p₂/kPa	141.44
冷气	总温 T_total，c/K	344
冷气	质量流量m_c/(mg/s)	101.25
动叶	动叶转速 $ω$ /(r/min)	8 450
动叶	壁面温度	绝热

Tab. 2 Computational boundary conditions

项目	边界条件	数值
进口	总压p_total，0/kPa	344.74
	总温T_total，0/K	712
	入流角 $α 0$ /( $°$ )	0
	湍流强度T_u/%	10
出口	静压p₂/kPa	141.44
冷气	总温 T_total，c/K	344
冷气	质量流量m_c/(mg/s)	101.25
动叶	动叶转速 $ω$ /(r/min)	8 450
动叶	壁面温度	绝热

Tab. 3 Average film cooling effectiveness of blade tip under three grid numbers

网格数量	$η ¯$
5.0 $×$ 10⁶	0.417
7.0 $×$ 10⁶	0.428
9.0 $×$ 10⁶	0.433

Tab. 3 Average film cooling effectiveness of blade tip under three grid numbers

网格数量	$η ¯$
5.0 $×$ 10⁶	0.417
7.0 $×$ 10⁶	0.428
9.0 $×$ 10⁶	0.433

Fig. 3 Structured mesh of blade domain

Fig. 4 Comparison of heat transfer coefficient contours at blade tip between turbulence model results and experimental data

Fig. 5 Streamlines at blade tip in case 1

Fig. 6 Streamlines at micro-rib blade tip structure

Fig. 7 Limiting streamlines at blade tip

Fig. 8 Leakage flow rates at blade tip structure

Fig. 9 Average total pressure loss coefficient at cross-section of flow passage 10 mm downstream of blade trailing edge

Fig. 10 Distribution of total pressure loss coefficient along blade height

Fig. 11 Heat transfer coefficient contours at blade tip

Fig. 13 Film cooling effectiveness contours at blade tip

Fig. 14 Distribution of average film cooling effectiveness along axial direction at blade tip

Fig. 15 Area-averaged film cooling effectiveness and effectiveness uniformity at blade tip

References 28

[1]	左秋儒，栾勇，熊逸辉，等.燃气轮机透平叶片旋流冷却技术研究综述[J]．发电技术，2024，45(5)：802-813．
	ZUO Q R， LUAN Y， XIONG Y H，et al ．Review of research on swirl cooling technology of gas turbine blades[J]．Power Generation Technology，2024，45(5)：802-813．
[2]	黄呈帅，梁健，李波，等.基于掺氢燃气轮机的综合能源系统热经济学性能研究[J]．中国电力，2024，57(1)：195-208．
	HUANG C S， LIANG J， LI B，et al ．Study on the thermo-economic performance of a integrated energy system based on hydrogen-fueled gas turbine[J]．Electric Power，2024，57(1)：195-208．
[3]	张燕京，许超，王更阳，等.氢燃料燃气轮机研究现状及技术进展[J]．分布式能源，2025，10(5)：10-20．
	ZHANG Y J， XU C， WANG G Y，et al ．Development status and technical progress of hydrogen-fueled gas turbines[J]．Distributed Energy，2025，10(5)：10-20．
[4]	郑开云，池捷成，张学锋.基于燃气轮机的双工质气体压缩储能系统[J]．南方能源建设，2025，12(6)：9-16．
	ZHENG K Y， CHI J C， ZHANG X F ．Gas turbine-based binary working fluid gas compression energy storage system[J]．Southern Energy Construction，2025，12(6)：9-16．
[5]	BUNKER R S ．Axial turbine blade tips：function，design，and durability[J]．Journal of Propulsion and Power，2006，22(2)：271-285． doi:10.2514/1.11818
[6]	PARK J S， LEE D H， CHO H H，et al ．Heat transfer and effectiveness on the film cooled tip and inner rim surfaces of a turbine blade[C]//ASME Turbo Expo 2010：Power for Land，Sea，and Air，2010：1751-1761． doi:10.1115/gt2010-23203
[7]	SENEL C B， MARAL H， KAVURMACIOGLU L A，et al ．An aerothermal study of the influence of squealer width and height near a HP turbine blade[J]．International Journal of Heat and Mass Transfer，2018，120：18-32． doi:10.1016/j.ijheatmasstransfer.2017.12.017
[8]	LEE S W， CHAE B J ．Effects of squealer rim height on aerodynamic losses downstream of a high-turning turbine rotor blade[J]．Experimental Thermal and Fluid Science，2008，32(8)：1440-1447． doi:10.1016/j.expthermflusci.2008.03.004
[9]	CAMCI C， DEY D， KAVURMACIOGLU L ．Tip leakage flows near partial squealer rims in an axial flow turbine stage[C]//ASME Turbo Expo 2003．Atlanta，Georgia，USA：ASME，2003：79-90． doi:10.1115/gt2003-38979
[10]	DU K， LI Z， LI J，et al ．Influences of a multi-cavity tip on the blade tip and the over tip casing aerothermal performance in a high pressure turbine cascade[J]．Applied Thermal Engineering，2019，147：347-360． doi:10.1016/j.applthermaleng.2018.10.093
[11]	姜世杰，李志刚，李军．肋条布局对涡轮动叶凹槽状叶顶传热和气动性能的影响研究[J]．推进技术，2020，41(5)：1103-1111．
	JIANG S J， LI Z G， LI J ．Study on the influence of rib layout on heat transfer and aerodynamic performance of groove tip of turbine rotor blade[J]．Journal of Propulsion Technology，2020，41(5)：1103-1111．
[12]	TONG F， GOU W， LI L，et al ．Numerical investigation of high pressure turbine blade tip-shaping effects on the aerothermal and dynamic performance[J]．Multidiscipline Modeling in Materials and Structures，2019，15(6)：1121-1135． doi:10.1108/mmms-03-2019-0053
[13]	EL-GHANDOUR M， MORI K， NAKAMURA Y ．Desensitization of tip clearance effects in axial flow turbines[J]．Journal of Fluid Science and Technology，2010，5(2)：317-330． doi:10.1299/jfst.5.317
[14]	高杰，郑群．叶顶凹槽形态对动叶气动性能的影响[J]．航空学报，2013，34(2)：218-226．
	GAO J， ZHENG Q ．Effect of squealer tip geometry on rotor blade aerodynamic performance[J]．Acta Aeronautica et Astronautica Sinica，2013，34(2)：218-226．
[15]	PARK J S， LEE S H， LEE W S，et al ．Heat transfer and secondary flow with a multicavity gas turbine blade tip[J]．Journal of Thermophysics and Heat Transfer，2016，30(1)：120-129． doi:10.2514/1.t4541
[16]	DU K， LI H， SUNDEN B，et al ．Effects of ribbed-cavity tip on the blade tip aerothermal performance in a high pressure turbine stage[J]．Journal of Thermal Science，2023，32(2)： 800-811． doi:10.1007/s11630-023-1771-5
[17]	WILHELM M， SCHIFFER H P ．Experimental investigation of rotor tip film cooling at an axial turbine with swirling inflow using pressure sensitive paint[J]．International Journal of Turbomachinery，Propulsion and Power，2019，4(3)：23. doi:10.3390/ijtpp4030023
[18]	杜昆，晏鑫，李军．燃气透平凹槽状叶顶气膜冷却特性研究[J]．燃气轮机技术，2014，27(1)：27-31．
	DU K， YAN X， LI J ．Investigations on the film cooling characteristics of the gas turbine blade with squealer tip[J]．Gas Turbine Technology，2014，27(1)：27-31．
[19]	JEONG J， KIM W， KWAK J，et al ．Heat transfer coefficient and film cooling effectiveness on the partial cavity tip of a gas turbine blade[J]．ASME Journal of Turbomachinery，2019，141(7)：071007． doi:10.1115/1.4042647
[20]	ZHOU Z， WANG S， CHEN S ．Numerical study of blade tip cooling at high speed with tip and pressure-side coolant injections[C]//ASME Turbo Expo 2018：Turbomachinery Technical Conference and Exposition．Oslo，Norway：ASME，2018：75915． doi:10.1115/gt2018-75915
[21]	郭嘉杰，王新军，鲍宇航．椭圆孔及偏转角对凹槽叶顶气膜冷却流动换热特性的影响[J]．西安交通大学学报，2021，55(1)：153-161．
	GUO J J， WANG X J， BAO Y H ．Effect of elliptical hole and deflection angle on flow and heat transfer characteristics of film cooling at grooved blade tip[J]．Journal of Xi’an Jiaotong University，2021，55(1)：153-161．
[22]	ZHANG B L， XIA J， YANG L P，et al ． Investigation of aerothermal performance of blade tip with conical holes in transonic flow[J]．Aerospace Science and Technology，2023，142：108590． doi:10.1016/j.ast.2023.108590
[23]	HUANG T， LI H， SU X，et al ．Influence of film hole arrangement on cooling and aerodynamic performance of blade tip with squealer structure[J]．International Journal of Thermal Sciences，2024，195：108636． doi:10.1016/j.ijthermalsci.2023.108636
[24]	许承天，李志刚，李军．涡轮动叶部分吸力侧肩壁凹槽状叶顶气热和冷却性能研究[J]．推进技术， 2022，43(10)：98-108．
	XU C T， LI Z G， LI J ．Study on gas heating and cooling performance of grooved blade tip of partial suction side shoulder wall of turbine rotor blade[J]．Journal of Propulsion Technology，2022，43(10)：98-108．
[25]	LIN J， LI H， YOU R，et al ．Experimental study on the film cooling characteristics of three complex tip structures[J]．Journal of Thermal Science，2023，32(4)：1378-1392． doi:10.1007/s11630-023-1831-x
[26]	BI S， MAO J， CHEN P，et al ．Effect of multiple cavities and tip injection on the aerothermal characteristics of the squealer tip in turbine stage[J]．Applied Thermal Engineering，2023，220：119631． doi:10.1016/j.applthermaleng.2022.119631
[27]	KWAK J S， HAN J C ．Heat-transfer coefficients of a turbine blade-tip and near-tip regions[J]．Journal of Thermophysics and Heat Transfer，2003，17(3)：297-303． doi:10.2514/2.6776
[28]	MA H， ZHANG Q， HE L，et al ．Cooling injection effect on a transonic squealer tip：part I：experimental heat transfer results and CFD validation[J]．Journal of Engineering for Gas Turbines and Power，2017，139(5)：052506． doi:10.1115/1.4035175