Visualization experiment on film distribution characteristics of shaped film holes based on thermochromic liquid crystal
摘要: 通过在气膜孔下游不同位置设置涂有热色液晶的黑色尼龙网,根据尼龙网上的彩色无量纲温度轮廓,对圆柱孔、水滴孔和簸箕孔在吹风比为0.5,1,2下的气膜分布状况进行可视化实验研究.结果表明:气膜孔沿主流流向的扩张会降低出流平均动量,较小程度地减弱了肾形对涡强度,使气膜的覆盖范围和气膜厚度都有所增大;展向扩张使出流平均动量降低的同时使其具有展向速度分量,明显降低了肾形对涡强度,显著增大气膜覆盖范围、降低气膜厚度,增强气膜的贴壁性;吹风比增大使气膜脱离壁面的趋势增强,降低气膜覆盖范围;排孔的相邻孔的出流会相互影响,有利于将气膜压向壁面,相比单孔来讲排孔的冷却效果和气膜覆盖效果更好.Abstract: Black nylon net coated with thermochromic liquid crystal was set at different locations downstream the film holes. The film distribution of cylindrical hole, water-drop hole and fan-shaped hole were visualized according to the colorful dimensionless temperature images on the nylon net under three blowing ratios of 0.5, 1 and 2. Results show that the stream-wise expansion of film hole weakens the exit mean momentum and intensity of kidney eddies slightly, so the coverage area and thickness of film are increased. The lateral expansion greatly improves the film coverage area and attachment performance by decreasing the intensity of the kidney eddies, exit mean momentum and film thickness and increasing the velocity in the spanwise direction. High blowing ratios make the film lift off the wall and decrease the film coverage aera. In addition, the interaction of jets issued from adjacent holes of film holes row has the effects of pressing the film towards the surface, making the cooling and coverage performance of film holes row better than that of an individual film hole.
 朱惠人,许都纯,刘松龄,等.气膜孔形状对流量系数影响的实验研究[J].推进技术,1988,19(1):42-45. ZHU Huiren,XU Duchun,LIU Songling,et al.The experimental investigation in the effects of film cooling holes shape on discharge coefficient[J].Journal of Propulsion Technology,1988,19(1):42-45.(in Chinese)  朱惠人,许都纯,刘松龄.气膜孔形状对排孔下游冷却效率的影响[J].航空学报,2002,23(1):75-78. ZHU Huiren,XU Duchun,LIU Songling.Effects of hole shape on film cooling effectiveness[J].Acta Aeronautica et Astronautica Sinica,2002,23(1):75-78.(in Chinese)  LIU Cunliang,ZHU Huiren,BAI Jiangtao,et al.Film cooling performance of converging slot holes with different exit- entry area ratio[R].ASME Paper 2009-GT-59002,2009.  BAI Jiangtao,ZHU Huiren,LIU Cunliang.Film cooling characteristic of double-fan shaped film cooling holes[R].ASME Paper 2009-GT-59318,2009.  LIU Cunliang,ZHU Huiren,BAI Jiangtao,et al.Film cooling performance of waist-shaped slot holes[R].ASME Paper 2010-GT-22237,2010.  LIU Cunliang,ZHU Huiren,BAI Jiangtao,et al.Experimental and numerical investigation on the film cooling of waist-shaped slot holes comparing with converging slot holes[J].Journal of Turbomachinery,2012,134(1):011021.1-011021.11.  LIU Cunliang,ZHU Huiren,BAI Jiangtao,et al.Experimental research on the thermal performance of converging slot holes with different divergence angles[J].Experimental Thermal and Fluid Science,2009,33(5):808-817.  Liu K,Yang S F,Han J C.Influence of coolant density on turbine blade film-cooling with axial shaped holes[R].ASME Paper 2012-HT-58144,2012.  Liu K,Yang S F,Han J C.Influence of coolant density on turbine blade film-cooling with compound-angle shaped holes[R].ASME Paper 2012-HT-69117,2012.  Wright L M,McClain S T,Clemenson M D.Effect of density ratio on flat plate film cooling with shaped holes using PSP[R].ASME Paper 2010-GT-23053,2010.  Wright L M,McClain S T,Clemenson M D.PIV investigation of the effect of freestream turbulence intensity on film cooling from fanshaped holes[R].ASME Paper 2011-GT-46127,2011.  Saumweber C,Schulz A.Free-stream effects on the cooling performance of cylindrical and fan-shaped cooling holes[J].Journal of Turbomachinery,2012,134(6):061007.1-061007.12.  Porter J S,Henderson A D,Walker G J.Influence of inlet velocity ratio on the outlet uniformity of a fan-shaped film cooling hole[R].ASME Paper 2009-GT-59581,2009.  刘存良,朱惠人,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,2008,23(4):598-604. LIU Cunliang,ZHU Huiren,BAI Jiangtao.Study on the physics of film-cooling effectiveness enhancement by the converging-expanding hole[J].Journal of Aerospace Power,2008,23(4):598-604.(in Chinese)  Hyams D G,Leylek J H.A detailed analysis of film cooling physics:Part Ⅲ streamwise injection with shaped holes[R].ASME Paper 97-GT-271,1997.  Bunker R S.A review of shaped hole turbine film cooling technology[J].Journal of Heat Transfer,2005,127(4):441-453.  梁俊宇,孟宝宝,康顺,等.平板气膜冷却孔下游湍流场的实验研究[J].动力工程学报,2012,32(6):435-439. LIANG Junyu,MENG Baobao,KANG Shun,et al.Experimental study of the turbulent flow downstream of film cooling holes on a flat plate[J].Journal of Chinese Society of Power Engineering,2012,32(6):435-439.(in Chinese)  Mee D J,Ireland P T,Bather S.Measurement of the temperature field downstream of simulated leading-edge film-cooling holes[J].Experiments in Fluids,1999,27(3):273-283.  Sargison J E,Oldfield M L G,Guo S M.Flow visualization of the external flow from a converging slot-hole film-cooling geometry[J].Experiments in Fluids,2005,38(3):304-318.  Ganzert W,Hildebrandt T,Fottner L.Systematic experimental and numerical investigations on the aerothermodynamics of a film cooled turbine cascade with variation of the cooling hole shape:Part 1 experimental approach[R].ASME Paper 2000-GT-295,2000.  刘存良.新型高效气膜孔冷却特性研究[D].西安:西北工业大学,2009. LIU Cunliang.Research on the film cooling characteristics of hig-performance shaped film holes[D].Xi'an:Northwestern Polytechnical University,2009.(in Chinese)
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