气膜孔形状对冷却效率影响的数值研究  

Numerical Study on the Influence of Hole's Shape on Film Cooling Efficiency

作　　者：戴萍[1,2] 林枫[3] 

机构地区：[1]哈尔滨工程大学动力与能源学院,哈尔滨150001 [2]青岛科技大学机电学院,青岛266061 [3]中国船舶重工集团第703研究所燃气轮机研究室,哈尔滨150036

出　　处：《动力工程》2009年第2期117-122,共6页Power Engineering

摘　　要：采用控制容积法对三维定常不可压缩雷诺时均紊流方程(N-S方程)进行了离散,并在吹风比M为0.6和1.2的情况下,利用非结构化网格及两层k-ε湍流模型,对气膜孔几何形状对涡轮叶片气膜冷却效率的影响进行了数值模拟,得到气膜孔附近的流场分布.结果表明:圆柱形孔的冷却效率随吹风比的增大而明显降低.前向扩张孔的冷却效率优于圆柱形孔,射流在叶高方向上扩展较广,在侧向孔间区域的气膜冷却效率较高.缩放槽缝孔在不同吹风比下的冷却效率均高于圆柱形孔和前向扩张孔,而且在孔下游较远区域,2个孔之间沿叶高方向的气膜覆盖性较好.缩放槽缝孔和前向扩张孔不同程度地抑制了反向涡旋对的产生,因而提高了射流对壁面的贴附性,增强了壁面的冷却效果.A three-dimensional steady and uncompressible N-S equation was discretized by volume-control method to simulate the effects of hole＇s geometry shapes on film cooling efficiency of turbine blade in combining with non-structural mesh and two-layer κ-ε turbulence model, with blowing ratio of 0.6 and 1.2, obtaining the flow field distribution near the film hole. Results show that the cooling efficiency with cylindrical holes obviously declines with the blowing ratio increasing. The cooling efficiency with forward diffused holes is superior than that with cylindrical holes, because of the jet flow expands wider along the span, and with a high efficiency at the lateral area between adjacent holes. The cooling efficiency with converged slot-hole is higher than that with cylindrical holes and forward diffused holes under different blowing ratios. Furthermore, the film has the good ability of blade coverage along the span between two holes within the area a bit far downstream the holes. The converged slot-hole and forward diffused hole could restrain the reversed vortex pair to form at different extent, hence to increase the attachable of the jet flow to the blade＇s wall, then to enhance the film cooling efficiency.

关 键 词：涡轮叶片 气膜孔 缩放槽缝孔 前向扩张孔 气膜冷却效率 湍流模型 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]