Effect of cooling stream injection on cooling characteristics of guide blade endwall
-
摘要:
为了研究涡轮导叶端壁前缘冷气射流结构对端壁气膜冷却特性的影响规律，设计了4种射流结构形式，采用试验和数值仿真相结合的方法研究了冷气射流几何参数和气动参数对导叶端壁绝热壁温的影响，得到以下结论：端壁低温区域呈现出“曲边三角形”特征，沿着叶栅通道中气流的流动方向，低温区急剧减小，且向着叶片吸力面剧烈偏转，最终在叶片吸力面尾缘处消失；端壁前缘冷气射流存在最佳结构，即当冷气出流面积比为0.072，射流孔面积比为2.0时，端壁绝热冷却效率达到最大值0.325；射流比对端壁绝热冷却效率有较大的影响，随着射流比的增大，绝热冷却效率逐渐增大，同时端壁最大绝热冷却效率出现的位置向着压力面发生偏移；在靠近端壁前缘区域内，温比对绝热冷却效率的影响甚微，变化幅度小于0.01，但在远离前缘的端壁区域内，绝热冷却效率随着温比增加而增大，最大增幅约为0.03。
Abstract:In order to study the effect law of the cooling jet structure at the leading edge of turbine guide blade endwall on the film cooling characteristics at endwall, four jet structures were designed. The effect of cooling jet geometric and aerodynamic parameters on the adiabatic wall temperature at the endwall was studied by a method of combining test and numerical simulation to obtain the following conclusions: the low-temperature region of the endwall presents a “curved triangle” feature, namely, along the air flow direction in the cascade channel, the low-temperature region decreases sharply and deflects substantially toward the blade suction surface, and finally disappears at the trailing edge of the blade suction surface, while an optimal cooling jet structure exists at the leading edge of the endwall, that is, when the cooling air outflow area ratio is 0.072 and the jet orifice area ratio is 2.0, the maximum adiabatic cooling efficiency at the endwall can reach 0.325; the jet ratio has a great influence on the adiabatic cooling efficiency of the endwall. With the increase of the jet ratio, the adiabatic cooling efficiency at the endwall gradually increases, while the position where the maximum adiabatic cooling efficiency at the endwall occurs shifts toward the pressure surface.Within the area near the leading edge of the endwall, the temperature ratio has little effect on the adiabatic cooling efficiency, and the change range is less than 0.01, but within the area away from the leading edge, the adiabatic cooling efficiency increases with the increase of the temperature ratio, and the maximum increase is about 0.03.
-
Key words:
- turbine blade /
- endwall /
- film cooling /
- adiabatic wall temperature /
- adiabatic cooling efficiency
-
图 7 端壁绝热温度场的试验结果
Figure 7. Experimental result of adiabatic temperature field of endwall
图 12 不同射流结构时端壁绝热壁温分布
Figure 12. Adiabatic wall temperature distributions of endwall with different jet structures
图 13 射流结构对端壁平均绝热冷却效率影响（Km=0.015）
Figure 13. Effect of jet structures on average adiabatic cooling efficiency of endwall （Km=0.015）
图 14 射流结构对端壁展向绝热冷效影响（x/L=0.25，Km =0.015）
Figure 14. Effect of jet structures on spanwise adiabatic cooling efficiency of end wall （x/L=0.25, Km =0.015）
图 15 射流比对应的端壁绝热壁温（Ka=0.09，Kah=1.65）
Figure 15. Adiabatic wall temperature of endwall corresponding to different jet ratio （Ka=0.09，Kah=1.65）
图 16 射流比对端壁展向平均绝热冷却效率影响
Figure 16. Effect of jet ratio on average spanwise adiabatic cooling efficiency of endwall
图 17 射流比对端壁展向绝热冷效影响（x/L=0.25，Ka=0.09，Kah=1.65）
Figure 17. Effect of jet ratio on spanwise adiabatic cooling efficiency of endwall （x/L=0.25，Ka=0.09，Kah=1.65）
图 18 温比对端壁平均绝热冷效影响（Ka=0.09，Kah=1.65）
Figure 18. Effect of temperature ratios on average adiabatic cooling efficiency of the endwall （Ka=0.09，Kah=1.65）
表 1 试验工况列表
Table 1. Table of test conditions
试验类型 b/d h/d Ka Kah Km Kt Re/105 流量比
影响5 4 0.09 1.65 0.012 1.25 1.2 0.015 0.018 0.02 温比
影响5 4 0.09 1.65 0.015 1.15 1.2 1.25 1.35 射流结构
影响5 4 0.072 2.0 0.015 1.25 1.2 0.09 1.65 0.11 1.71 0.13 1.58 
下载: 导出CSV
-
[1] 李国强,岳彭,朱凯迪,等. 冷气掺混对涡轮叶栅气动性能影响试验研究[J]. 热能动力工程,2019,34(1): 17-22.LI Guoqiang,YUE Peng,ZHU Kaidi,et al. Study on aerodynamic performance of turbine cascade with cooling-air ejection[J]. Journal of Engineering for Thermal Energy and Power,2019,34(1): 17-22. (in Chinese) [2] 刘昊,刘亮亮,沈昕,等. 透平叶栅端部二次流流动损失机制研究[J]. 热力透平,2018,47(4): 252-257. doi: 10.13707/j.cnki.31-1922/th.2018.04.003LIU Hao,LIU Liangliang,SHEN Xin,et al. Investigation on the loss mechanism of secondary flow in turbine cascade endwall[J]. Thermal Turbine,2018,47(4): 252-257. (in Chinese) doi: 10.13707/j.cnki.31-1922/th.2018.04.003 [3] THOLE K A,KNOST D G. Heat transfer and film-cooling for the endwall of a first stage turbine vane[J]. International Journal of Heat and Mass Transfer,2005,48(25/26): 5255-5269. [4] THRIFT A A,THOLE K A,HADA S. Effects of an axisymmetric contoured endwall on a nozzle guide vane: adiabatic effectiveness measurements[J]. Journal of Turbomachinery,2011,133(4): 041007.1-041007.10. [5] BLAIR M F. An experimental study of heat transfer and film cooling on large-scale turbine endwalls[J]. Journal of Heat Transfer,1974,96(4): 524-531. doi: 10.1115/1.3450239 [6] HAN C,CHI Z,REN J,et al. Optimal arrangement of combined-hole for improving film cooling effectiveness[J]. Journal of Thermal Science and Engineering Applications,2015,7(1): 011010.1-011010.13. doi: 10.1115/1.4028976 [7] SONG L,ZHU P,LI J,et al. Effect of purge flow on endwall flow and heat transfer characteristics of a gas turbine blade[J]. Applied Thermal Engineering,2017,110: 504-520. doi: 10.1016/j.applthermaleng.2016.08.172 [8] 姚韵嘉, 祝培源, 陈云, 等. 间隙位置对叶片端壁气膜冷却性能影响的实验研究[J]. 工程热物理学报, 2019, 40(10): 2327-2333.YAO Yunjia, ZHU Peiyuan, CHEN Yun, et al. Experimental study on the effect of the location of slot jet on film cooling performance of endwall[J]. Journal of Engineering Thermophysics, 2019, 40(10): 2327-2333. (in Chinese) [9] LYNCH S P,THOLE K A. The effect of combustor-turbine interface gap leakage on the endwall heat transfer for a nozzle guide vane[J]. Journal of Turbomachinery,2008,130(4): 041019.1-041019.10. [10] THRIFT A A,THOLE K A,HADA S. Effects of orientation and position of the combustor-turbine interface on the cooling of a vane endwall[J]. Journal of Turbomachinery,2012,134(6): 061019.1-061019.10. [11] 张杰,刘存良,张丽,等. 槽缝射流和泄漏间隙对轴对称涡轮端壁换热特性的影响[J]. 推进技术,2022,43(4): 200-208.ZHANG Jie,LIU Cunliang,ZHANG Li,et al. Effects of slot injection and leakage gap on heat transfer characteristics of an axisymmetric turbine endwall[J]. Jurnal of Propulsion Technology,2022,43(4): 200-208. (in Chinese) [12] 祝培源, 陶志, 姚韵嘉, 等. 槽缝射流对环形叶栅端壁气膜冷却性能影响的实验研究[J]. 西安交通大学学报, 2019, 53(11): 63-70.ZHU Peiyuan, TAO Zhi, YAO Yunjia, et al. Expeimental study on the effect of purge flow on film cooling performance of an annular cascade endwall[J]. Journal of Xi’an Jiaotong University, 2019, 53(11): 63-70. (in Chinese) [13] CARDWELL N D,SUNDARAM N,THOLE K A. The effects of varying the combustor-turbine gap[J]. Journal of Turbomachinery,2007,129(4): 756-764. doi: 10.1115/1.2720497 [14] CARDWELL N D,SUNDARAM N,THOLE K A. Effect of midpassage gap, endwall misalignment, and roughness on endwall film-cooling[J]. Journal of Turbomachinery,2006,128(1): 62-70. doi: 10.1115/1.2098791 [15] 白波,李志刚,李军. 上游台阶结构对跨声速透平叶栅端壁气膜冷却性能的影响[J]. 西安交通大学学报,2020,54(5): 1-8.BAI Bo,LI Zhigang,LI Jun. Investigation on the effect of upstream step geometry on endwall film cooling characteristics of a transonic turbine cascade[J]. Journal of Xi’an Jiaotong University,2020,54(5): 1-8. (in Chinese) [16] 刘璐萱,李志刚,李军. 进口端壁不重合对跨声速透平叶栅端壁流动和传热特性影响的研究[J]. 西安交通大学学报,2018,52(11): 37-44. doi: 10.7652/xjtuxb201811006LIU Luxuan,LI Zhigang,LI Jun. Investigations on the effect of misalignment of inlet endwall on the endwall secondary flow field and heat transfer characteristics in a transonic turbine cascade[J]. Journal of Xi’an Jiaotong University,2018,52(11): 37-44. (in Chinese) doi: 10.7652/xjtuxb201811006 [17] YANG Weihua,SHI Xiaoxiang,ZHANG Jingzhou. Experimental investigation on film cooling characteristics of ellipse-shaped tab[J]. Experimental Thermal and Fluid Science,2017,81: 277-290. doi: 10.1016/j.expthermflusci.2016.10.018 [18] LI Yang, LIU Tao, TAO Jianjun, et al. Heat transfer characteristics in a narrow confined channel with discrete impingement cooling[J]. Chinese Journal of Aeronautics, 2022, 35(4): 220-229. [19] LANGSTON L S. Crossflows in a turbine cascade passage[J]. Journal of Engineering for Power, 1980, 102(4): 866-847. [20] SHARMA O P,BUTLER T L. Predictions of endwall losses and secondary flows in axial flow turbine cascades[J]. Journal of Turbomachinery,1987,109(2): 229-236. doi: 10.1115/1.3262089 -
点击查看大图
计量
- 文章访问数: 450
- HTML浏览量: 270
- PDF量: 68
- 被引次数: 0