污染物沉积和热障涂层脱落对气膜冷却效率影响的数值研究

推进技术 ›› 2013, Vol. 34 ›› Issue (10): 1362-1368.

污染物沉积和热障涂层脱落对气膜冷却效率影响的数值研究

杨晓军^1,2,许诺然¹, 刘智刚¹

中国民航大学航空工程学院,天津 300300;中国民航大学航空工程学院,天津 300300;中国民航大学航空工程学院,天津 300300

发布日期:2021-08-15
作者简介:杨晓军(1980—),男,博士,研究领域为航空发动机热防护及发动机适航审定技术。 E-mail:xiaojunyoung@hotmail.com
基金资助:
中央高校基本科研业务费中国民航大学专项“叶片气膜冷却机理研究”(ZXH2012H004)。

Effects of Deposition and Thermal Barrier Coating Spallation on Film Cooling Effectiveness:a Numerical Study

School of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China;School of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China;School of Aeronautical Engineering, Civil Aviation University of China, Tianjin 300300, China

Published:2021-08-15

摘要/Abstract

摘要： 污染物沉积到有热障涂层的涡轮叶片上之后,会导致叶片表面状况的改变,进而影响气膜冷却效率。为分析影响规律,利用三维数值计算研究了3种典型情况下的气膜冷却特性:污染物沉积、热障涂层脱落及气膜孔堵塞,并得到了吹风比的影响规律。研究结果表明,平板气膜冷却吹风比为0.5时,冷却效果最佳；在发生沉积和堵塞后,气膜孔附近产生的反旋涡对会削弱沉积和堵塞后的气膜冷却效率,沉积高度增加会强化这种削弱效果；由于在沉积情况下高吹风比会诱导出正向旋涡使得气膜贴近壁面,因此随着吹风比增大,气膜冷却效果增强；因涂层脱落而在孔下游产生的裂纹在低吹风比时会降低冷却效率,高吹风比时改进冷却效果,使得最佳吹风比由0.5上升到0.7左右；气膜孔堵塞会降低冷却效率,使得气膜更易脱离壁面。 

关键词: 气膜冷却;沉积;脱落;堵塞;冷却效率 

Abstract: With the increase of turbine inlet temperature, particulate matter existing in the hot gas path can be more easily deposited around the film hole and block the film flow. This is also the main cause of thermal barrier coating spallation due to the change of surface conditions after deposition. Firstly, increase of roughness enhances the heat transfer. Then, deposition will change the temperature field and the thermal stress around film hole. Therefore, it is important to analyze the effects of deposition, spallation and blockage on the film cooling effectiveness. A numerical analysis was conducted on flat plat by use of commercial computational code CFX. It was found that optimum blowing ratio(M) is around 0.5, which is in line with other studies. In the case of deposition and blockage, counter-rotating vortex pairs (CVP) induced around film hole can decrease the film cooling effectiveness. Height of deposition will reinforce this weakened effect. With the increase of blowing ratio, film cooling area will be enlarged with deposition presented due to high cooling flow and the effect of co-rotating vortex pairs which drives film close to wall. Spallation located in the downstream of hole can decrease film cooling effectiveness at low blowing ratio(M=0.25,0.5) and augment it at high blowing ratio(M=1.0,1.5). It also increases the optimum blowing ratio from 0.5to 0.7. Hole blockage decreases film cooling effectiveness and decreases the blowing ratio under which the film will penetrate the main stream. 

Key words: Film cooling; Deposition; Spallation; Blockage; Cooling Effectiveness

杨晓军,许诺然,刘智刚. 污染物沉积和热障涂层脱落对气膜冷却效率影响的数值研究[J]. 推进技术, 2013, 34(10): 1362-1368.

YANG Xiao-jun^1,2,XU Nuo-ran¹, LIU Zhi-gang¹. Effects of Deposition and Thermal Barrier Coating Spallation on Film Cooling Effectiveness:a Numerical Study[J]. Journal of Propulsion Technology, 2013, 34(10): 1362-1368.

参考文献

[1] 戴萍,林枫.横向槽结构对气膜冷却效果影响的数值研究[J].推进技术,2011,32(2):253-260.(DAI Ping,LIN Feng.Numercal Investigstion on the Influence of Transverse Slot Configuration on Film Coding Effect[J].Journal of Propulsion Technology,2011,2(2):253-260.)
[2] 杨彬,徐国强,孟恒辉,等.旋转状态下曲率模型上的气膜冷却效率[J].推进技术.2009,30(3):273-279.(YANG Bin,XU Guo-qiang,MENG Heng-hui,et al.Adiabatic Effectivenes Measurements on Rotating Chrvature Models[J].Journal of Propulsion Technology,2009,0(3):273-279.)
[3] 戴萍,林枫.燃气轮机叶片气膜冷却研究进展[J].热能动力工程,2009,4(1):1-6.
[4] Evans A G, Hutchinson J W.The Mechanics of Coating Delamination in Thermal Gradients [J].Surface & Coating Technology, 2007,1:7905-7916.
[5] Ekkad S V, Han J C.Film Cooling Measurements on Cylindrical Models with Simulated Thermal Barrier Coating Spallation [J].Journal of Thermophysics and Heat Transfer, 2000,4(2):194-200.
[6] Sundaram N, Thole K A.Effects of Surface Deposition, Hole Blockage, and TBC Spallation on Vane Endwall Film-Cooling [R].ASME 2006-GT-90379.
[7] Jeffrey P B, Christensen K T.A Comparison of Real and Simulated Surface Roughness Characterizations [R].AIAA 2007-3997.
[8] Bogard D G, Schmidt D L, Tabbita M.Characterization and Laboratory Simulation of Turbine Airfoil Surface Roughness and Associated Heat Transfer [J].Journal of Turbomachinery, 1998,0:337-342.
[9] Ekkad S, Han J C.Detailed Heat Transfer Distributions on a Cylindrical Model with Simulated TBC Spallation [R].AIAA 97-0595.
[10] Ekkad S V, Han J C.Film Cooling Measurements on Cylindrical Models with Simulated Thermal Barrier Coating Spallation [J].Journal of Thermophysics and Heat Transfer, 2000,2(2):194-200.
[11] Seth A L, Karen A T.Simulations of Multi-Phase Particle Deposition on Endwall Film-Cooling Holes in Transverse Trenches [R].ASME 2011-GT-45190.
[12] Seth A L, Karen A T, Yoji O, et al.Simulations of Multi-Phase Particle Deposition on a Showerhead with Staggered Film-Cooling Holes [R].ASME 2011-GT-45191.
[13] Albet J E, Bogard D G.Experimental Simulation of Contaminant Deposition on a Film Cooled Turbine Vane Pressure Side with a Trench [R].ASME 2011-GT-46709.
[14] 李保岐,段绪海.二氧化锆在航空发动机上的应用[J].航空工艺技术,1999,3:33-34.
[15] 李珑,袁峰,竺晓程,等.小孔射流对环形叶栅吸力面流场影响的实验研究[J].动力工程,2005,5:306-311.
[16] 刘存良,朱慧人,白江涛.收缩－扩张形气膜孔提高气膜冷却效率的机理研究[J].航空动力学报,2008,3(4):598-604.
[17] Jovanovic′ M B,Lange H C de,Steenhoven A A Van.Influence of Hole Imperfection on Jet Cross Flow Inter Action[J].International Journal of Heat and Fluid Flow,2006:42-53.