心形孔气膜冷却特性的数值模拟
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摘要
为进一步提高航空发动机热端部件的冷却效率,提出了心形气膜冷却孔结构,利用数值模拟分析心形孔的流场特性和冷却特性,并通过与常规圆形孔计算结果的对比,揭示心形气膜孔强化冷却的物理机制.计算结果表明:与圆形孔相比,心形孔能有效抑制反向旋转涡对的生成,冷却气流的贴壁效果得到明显提高,同时心形孔的扩展出口结构使得冷却气流在展向上的分布更为均匀,展向平均气膜冷却效率得到显著提高;在吹风比为0.5~2.0内,心形孔的全局平均冷却效率相对于圆形孔分别提高了70.93%,246.94%,598.9%和879.07%;从热流比分布来看,心形孔在吹风比为1.5下的热流比值最低,表征在吹风比为1.5下心形孔对壁面的保护效果最好.
A heart shaped film cooling hole was firstly presented to improve the cooling effectiveness of modern gas turbine.The flow field performance and cooling performance were analyzed through numerical simulation.The result of heart shaped film cooling hole was compared with that of cylindrical film cooling hole.The comparisons show that the heart shaped film cooling hole can reduce the strength of counter rotating vortex pair,thus the coolant-surface attachment is improved.For heart shaped film cooling hole,the expansion structure on the hole exit allows the coolant to flow along spanwise direction,resulting in a better spanwise averaged film cooling effectiveness than that of cylindrical hole.By compa-ring with cylindrical hole,the heart shaped hole increases the film cooling performance.The heart shaped film cooling hole shows enhancements of approximately 70.93%,246.94%,598.9% and 879.07%at blowing ratio of 0.5-2.0,respectively.In terms of heat-flux ratio,the hearted shaped hole shows the lowest heat-flux ratio at blowing ratio of 1.5,indicating that the hearted shaped hole provides the best film cooling performance at blowing ratio of 1.5.
A heart shaped film cooling hole was firstly presented to improve the cooling effectiveness of modern gas turbine.The flow field performance and cooling performance were analyzed through numerical simulation.The result of heart shaped film cooling hole was compared with that of cylindrical film cooling hole.The comparisons show that the heart shaped film cooling hole can reduce the strength of counter rotating vortex pair,thus the coolant-surface attachment is improved.For heart shaped film cooling hole,the expansion structure on the hole exit allows the coolant to flow along spanwise direction,resulting in a better spanwise averaged film cooling effectiveness than that of cylindrical hole.By compa-ring with cylindrical hole,the heart shaped hole increases the film cooling performance.The heart shaped film cooling hole shows enhancements of approximately 70.93%,246.94%,598.9% and 879.07%at blowing ratio of 0.5-2.0,respectively.In terms of heat-flux ratio,the hearted shaped hole shows the lowest heat-flux ratio at blowing ratio of 1.5,indicating that the hearted shaped hole provides the best film cooling performance at blowing ratio of 1.5.
引文
[1]林宏镇,汪火光,蒋章焰.高性能航空发动机传热技术[M].北京:国防工业出版社,2005.
[2]杨卫华,李永康,张靖周,等.突片作用下气膜冷却效率的试验研究[J].航空动力学报,2007,22(3):380-383.YANG Weihua,LI Yongkang,ZHANG Jingzhou,et al.Experimental study of cooling efficiency of film cooling with tab[J].Journal of Aerospace Power,2007,22(3):380-383.(in Chinese)
[3]何立明,苏建勇,白晓峰,等.等离子体气动激励改善气膜冷却效率的数值研究[J].空军工程大学学报:自然科学版,2008,9(3):1-5.HE Liming,SU Jianyong,BAI Xiaofeng,et al.Numerical investigation on improvement of film cooling efficiency with the plasma actuation[J].Journal of Air Force Engineering University:Natural Science Edition,2008,9(3):1-5.(in Chinese)
[4]Sinha A K,Bogard D,Crawford M.Film-cooling effectiveness downstream of a single row of holes with variable density ratio[J].Journal of Turbomachinery,1991,113(3):442-449.
[5]Sen B,Schmidt D L,Bogard D G.Film cooling with compound angle holes:heat transfer[J].Journal of Turbomachinery,1996,118(4):800-806.
[6]Schmidt D L,Sen B,Bogard D G.Film cooling with compound angle holes:adiabatic effectiveness[J].Journal of Turbomachinery,1996,118(4):807-813.
[7]Fric T F,Roshko A.Structure in the near field of the transverse jet[J].Turbulent Shear Flows,1981,77(2):175-180.
[8]Goldstein R J,Eckert E R G,Burggraf F.Effects of hole geometry and density on three-dimensional film cooling[J].International Journal of Heat and Mass Transfer,1974,17(5):595-607.
[9]Gritsch M,Colban W,Schar H,et al.Effect of hole geometry on the thermal performance of fan-shaped film cooling holes[J].Journal of Turbomachinery,2005,127(4):718-725.
[10]郭涛,朱惠人,许都纯.双排簸箕形气膜孔下游换热研究[J].航空动力学报,2009,24(7):1488-1492.GUO Tao,ZHU Huiren,XU Duchun.Investigation on film cooling heat transfer for double row dust-pan shaped holes[J].Journal of Aerospace Power,2009,24(7):1488-1492.(in Chinese)
[11]Lee H W,Park J J,Lee J S.Flow visualization and film cooling effectiveness measurements around shaped holes with compound angle orientations[J].International Journal of Heat and Mass Transfer,2002,45(1):145-156.
[12]Sargison J E,Guo S M,Oldfield M L G,et al.A converging slot-hole film-cooling geometry:Part 1low-speed flat-plate heat transfer and loss[R].ASME Paper 2001-GT-0126,2001.
[13]姚玉,张靖周,何飞,等.涡轮叶片吸力面上收敛缝形孔气膜冷却效率的数值研究[J].航空学报,2010,31(6):1115-1120.YAO Yu,ZHANG Jingzhou,HE Fei,et al.Numerical investigation on film cooling effectiveness of converging slot hole at turbine blade suction surface[J].Acta Aeronautica et Astronautica Sinica,2010,31(6):1115-1120.(in Chinese)
[14]Heidmann J,Ekkad S.A novel anti-vortex turbine film cooling hole concept[R].ASME Paper GT2007-27528,2007.
[15]Karsten K,Nurettin T,Dieter B.Experimental and numerical investigations of the nekomimi film cooling technology[R].ASME Paper GT2012-68400,2012.
[16]Ching P L,Steven R B,Ronald S B.Chevron film cooled wall:US,7328580[P].2008-02-12.
[17]Yoji O,Masakazu N.Film effectiveness performance of an arrowhead-shaped film-cooling hole geometry[J].Journal of Turbomachinery,2006,129(2):331-339.
[18]Dhungel A,Yu L,Philips W,et al.Film cooling from a row of holes supplemented with antivortex holes[J].Journal of Turbomachinery,2009,131(2):375-384.
[19]Ely M J,Jubran B A.A numerical evaluation on the effect of sister holes on film cooling effectiveness and the surrounding flow field[J].Heat and Mass Transfer,2009,45(11):1435-1446.
[20]WANG Jianhua,ZHU Yejun,KUANG Jian,et al.Numerical investigation on film cooling performance[R].ASME Paper GT2011-45775,2011.
[21]LIU Cunliang,ZHU Huiren,BAI Jiangtao.New development of the turbulent prandtl number models for the computation of film cooling effectiveness[J].International Journal of Heat and Mass Transfer,2011,54(4):874-886.
[22]SHAN Yong,ZHANG Jingzhou.Numerical investigation on film-cooling characteristics from a row of holes with ridge-shaped tabs[J].Journal of Enhanced Heat Transfer,2013,20(3):251-265.
[2]杨卫华,李永康,张靖周,等.突片作用下气膜冷却效率的试验研究[J].航空动力学报,2007,22(3):380-383.YANG Weihua,LI Yongkang,ZHANG Jingzhou,et al.Experimental study of cooling efficiency of film cooling with tab[J].Journal of Aerospace Power,2007,22(3):380-383.(in Chinese)
[3]何立明,苏建勇,白晓峰,等.等离子体气动激励改善气膜冷却效率的数值研究[J].空军工程大学学报:自然科学版,2008,9(3):1-5.HE Liming,SU Jianyong,BAI Xiaofeng,et al.Numerical investigation on improvement of film cooling efficiency with the plasma actuation[J].Journal of Air Force Engineering University:Natural Science Edition,2008,9(3):1-5.(in Chinese)
[4]Sinha A K,Bogard D,Crawford M.Film-cooling effectiveness downstream of a single row of holes with variable density ratio[J].Journal of Turbomachinery,1991,113(3):442-449.
[5]Sen B,Schmidt D L,Bogard D G.Film cooling with compound angle holes:heat transfer[J].Journal of Turbomachinery,1996,118(4):800-806.
[6]Schmidt D L,Sen B,Bogard D G.Film cooling with compound angle holes:adiabatic effectiveness[J].Journal of Turbomachinery,1996,118(4):807-813.
[7]Fric T F,Roshko A.Structure in the near field of the transverse jet[J].Turbulent Shear Flows,1981,77(2):175-180.
[8]Goldstein R J,Eckert E R G,Burggraf F.Effects of hole geometry and density on three-dimensional film cooling[J].International Journal of Heat and Mass Transfer,1974,17(5):595-607.
[9]Gritsch M,Colban W,Schar H,et al.Effect of hole geometry on the thermal performance of fan-shaped film cooling holes[J].Journal of Turbomachinery,2005,127(4):718-725.
[10]郭涛,朱惠人,许都纯.双排簸箕形气膜孔下游换热研究[J].航空动力学报,2009,24(7):1488-1492.GUO Tao,ZHU Huiren,XU Duchun.Investigation on film cooling heat transfer for double row dust-pan shaped holes[J].Journal of Aerospace Power,2009,24(7):1488-1492.(in Chinese)
[11]Lee H W,Park J J,Lee J S.Flow visualization and film cooling effectiveness measurements around shaped holes with compound angle orientations[J].International Journal of Heat and Mass Transfer,2002,45(1):145-156.
[12]Sargison J E,Guo S M,Oldfield M L G,et al.A converging slot-hole film-cooling geometry:Part 1low-speed flat-plate heat transfer and loss[R].ASME Paper 2001-GT-0126,2001.
[13]姚玉,张靖周,何飞,等.涡轮叶片吸力面上收敛缝形孔气膜冷却效率的数值研究[J].航空学报,2010,31(6):1115-1120.YAO Yu,ZHANG Jingzhou,HE Fei,et al.Numerical investigation on film cooling effectiveness of converging slot hole at turbine blade suction surface[J].Acta Aeronautica et Astronautica Sinica,2010,31(6):1115-1120.(in Chinese)
[14]Heidmann J,Ekkad S.A novel anti-vortex turbine film cooling hole concept[R].ASME Paper GT2007-27528,2007.
[15]Karsten K,Nurettin T,Dieter B.Experimental and numerical investigations of the nekomimi film cooling technology[R].ASME Paper GT2012-68400,2012.
[16]Ching P L,Steven R B,Ronald S B.Chevron film cooled wall:US,7328580[P].2008-02-12.
[17]Yoji O,Masakazu N.Film effectiveness performance of an arrowhead-shaped film-cooling hole geometry[J].Journal of Turbomachinery,2006,129(2):331-339.
[18]Dhungel A,Yu L,Philips W,et al.Film cooling from a row of holes supplemented with antivortex holes[J].Journal of Turbomachinery,2009,131(2):375-384.
[19]Ely M J,Jubran B A.A numerical evaluation on the effect of sister holes on film cooling effectiveness and the surrounding flow field[J].Heat and Mass Transfer,2009,45(11):1435-1446.
[20]WANG Jianhua,ZHU Yejun,KUANG Jian,et al.Numerical investigation on film cooling performance[R].ASME Paper GT2011-45775,2011.
[21]LIU Cunliang,ZHU Huiren,BAI Jiangtao.New development of the turbulent prandtl number models for the computation of film cooling effectiveness[J].International Journal of Heat and Mass Transfer,2011,54(4):874-886.
[22]SHAN Yong,ZHANG Jingzhou.Numerical investigation on film-cooling characteristics from a row of holes with ridge-shaped tabs[J].Journal of Enhanced Heat Transfer,2013,20(3):251-265.