Abstract: In order to explore the performance of improving film cooling by sawtooth compared to transverse slot，the flow and the temperature distribution，film cooling effectiveness of these two structures which have the hole pitches of 2，3，4，respectively，were numerically investigated at blowing ratios of 0.5 and 1.5，respectively. The results show that the computational values of film cooling effectiveness by transverse slot agree with the experimental data. The sawtooth slots have a strong ability of the spanwise spreading of the coolant compared to the transverse slots. With the increases of hole pitches，the vortex pairs existing hole center line become weak and the additional vortex pairs easily appear at the midspan region，resulting in that film cooling effectiveness of sawtooth slot is much higher than that of transverse slot. At blowing ratio of 0.5，the surface averaged film effectiveness of sawtooth slot is higher 27%，35% and 42%，respectively than that of transverse slot with hole pitches of 2，3 and 4. At blowing ratio of 1.5，the surface averaged film effectiveness of sawtooth slot is higher 27%，95% and 151% than that of transverse slot with hole pitches of 2，3 and 4.

Key words: Film cooling；Sawtooth slot；Vortex；Cooling effectiveness；Turbine

摘要： 为了探索锯齿槽比横向槽气膜冷却更有效的机理，数值模拟研究了不同气膜孔间距下锯齿槽和横向槽下游流场、温度场及气膜冷却效率分布。吹风比为0.5和1.5，孔间距与气膜孔直径的比分别为2、3、4。结果表明:横向槽气膜冷却效率计算结果和实验数据吻合较好。相比于横向槽，锯齿槽展向导流能力增强。随着孔间距增加，孔中心线处漩涡对减弱，孔间区域更容易形成附加漩涡对，锯齿槽比横向槽气膜冷却效率提高更明显。孔间距p/D分别为2、3、4，吹风比0.5时，锯齿槽比横向槽面平均气膜冷却效率分别提高27%、35%和42%；吹风比1.5时，锯齿槽比横向槽面平均气膜冷却效率分别提高27%、95%和151%。

关键词: 薄膜冷却；锯齿槽；漩涡；冷却效率；涡轮