Numerical investigation of impingement and heat transfer on inner surface of airfoil former cavity with film holes
-
摘要: 采用数值模拟方法对不同雷诺数下静止状态涡轮叶片前腔带气膜孔出流的冲击流动与换热特性进行了研究.分析了叶片前缘冲击流动产生的不同涡团对其内表面换热的作用机理.计算结果表明:相同雷诺数下,叶片前缘内表面气膜孔附近的换热强化比高于通道的平均值.随着雷诺数增加,换热强化比有所提高.冲击流动与通道流动耦合而形成的波浪形涡区,极大地扩展了冲击强化换热区域.气膜孔出流的抽吸作用对冲击流产生影响,进一步扩大了冷却空气在前缘内表面的覆盖范围.气膜腔叶根处纵向截面的涡团阻碍了冷气向叶根方向扩展,降低了冷却效率;而横向截面的涡团则促进冷气与壁面热气的掺混,提升了换热效果.Abstract: Numerical simulations of impingement and heat transfer in a static airfoil former cavity with film holes were performed on conditions at different Reynolds numbers. Flows of the vortex by impingement on heat transfer mechanism was analyzed on the inner surface of leading-edge. The numerical result shows: heat transfer enhancement on the area near film holes is higher than the average value of channel at the same Reynolds number and it increases slightly with the higher Reynolds number. Wavy area of vortex generated by impingement and cross-flow extends the scope of enhanced heat transfer greatly. Suction effect of film holes flow generates an impact on impingement and enlarges the covering area of cooling air on the inner surface of leading-edge furthermore. Vortex in the vertical section of the film chamber root hinders cooling air flowing there and results in a lower cooling efficiency. While vortex in the cross-section promotes the mixing of cold and hot air near the wall with an enhancement in heat transfer.
-
Key words:
- turbine blades /
- leading-edge /
- film /
- impinging /
- cooling /
- numerical analysis
-
[1] Schabacker J,Boles A,Johnson B V.PIV investigation of the flow characteristics in an internal coolant passange with 45° rib arrangement.ASME Paper No.99-GT-120,1999 [2] Liou T M,Wu Y Y.LDV measurements of periodic fully developed main and secondary flows in a channel with rib-disturbed walls[J].Journal of Fluids Engineering,1993,115:109-114 [3] 刘传凯,陶智,丁水汀,等.3种转角下旋转U形方通道的局部换热[J].北京航空航天大学学报,2006,32(3):284-287 Liu Chuankai,Tao Zhi,Ding Shuiting,et al.Local heat transfer in a rotating U-shaped square channel with three channel orientations[J].Journal of Beijing University of Aeronautics and Astronautics,2006,32(3):284-287(in Chinese) [4] Metzger D E,Bunker R S.Local heat transfer in internally cooled turbine airfoil leading edge regions:part 11—impingement cooling with film coolant extraction[J].Journal of Turbomachinery,1990,112:459-466 [5] Taslim M E,Setayeshgar L,Spring S D.An experimental evaluation of advanced leading edge impingement cooling concepts[J].Journal of Turbomachinery,2001,123:147-153 [6] Taslim M E,Pan Y,Spring S D.An experimental study of impingement on roughened airfoil leading-edge walls with film holes[J].Journal of Transactions,2001,123:766-773 [7] Taslim M E,Khanicheh A.Experimental and numerical study of impingement on an airfoil leading edge with and without showerhead and gill film holes[J].Journal of Transactions,2006,128:310-320 [8] Rama Kumar B V N ,Prasad B V S S S.Experimental investigation of flow and heat transfer for single and multiple rows of circular jets impinging on a concave surface.ASME GT 2008-51044,2008 [9] Alvarez J J,de la Calzada P,Krulic G.Heat transfer and flow characteristics of a leading edge impingement cooling system for low pressure turbine vanes.ASME GT 2008-50142,2008 [10] Taslim M E,Bethka D.Experimental and numerical impingement heat transfer in an airfoil leading-edge cooling channel with cross-flow[J].Journal of Turbomachinery,2009,131:011021.1-7 [11] 王开,徐国强,孙纪宁,等.冲击与气膜的组合形式对冷却效果的影响[J].北京航空航天大学学报,2008,34(7):751-754 Wang Kai,Xu Guoqiang,Sun Jining,et al.Effect of combined impingement cooling and fi1m cooling on hybrid cooling effectiveness[J].Journal of Beijing University of Aeronautics and Astronautics,2008,34(7):751-754( in Chinese) [12] 杨世铭,陶文铨.传热学[M].3版.北京:高等教育出版社,1998:165-166 Yang Shiming,Tao Wenquan.Heat transfer[M].3ed.Beijing:Higher Education Press,1998:165-166(in Chinese)
点击查看大图
计量
- 文章访问数: 2439
- HTML全文浏览量: 5
- PDF下载量: 609
- 被引次数: 0