主流偏角对单排圆柱型气膜孔冷却特性的影响

数值模拟研究了主流偏角对单排圆柱型气膜孔冷却特性的影响,在气膜孔中心间距相等的计算条件下,在吹风比为1.0时,计算结果与主流和气膜孔都无偏角、主流无偏角而气膜孔有45°偏角这两种流动情况做了对比.结果显示:相对于主流和气膜孔都无偏角时,主流有45°偏角而气膜孔无偏角时气膜平均冷却效率更大,分布更均匀;相比于主流无偏角而气膜孔有45°偏角时,在气膜孔附近处,主流有45°偏角而气膜孔无偏角时气膜平均冷却效率更小,在远离气膜孔的下游位置处,气膜平均冷却效率更大.另外在吹风比为0.5和1.5条件下进行了数值模拟,结果也显示3种流动情况气膜冷却效率分布存在明显差距,有必要对主流偏角对单排气膜孔冷却特性的影响做进一步的实验和数值研究.

Effect of main flow orientation angle on cooling characteristics of single row of cylindrical film cooling holes

The effect of main flow orientation angle on the film cooling characteristics of single row of cylindrical film cooling holes was numerically studied. With the same distance between the centers of film cooling holes when the blowing ratio was 1.0,results were compared with two other reference flow configurations of single row of cooling holes. Main flow orientation angle was 0 degree and the hole compound angle was 0 degree in one reference configuration, while main flow orientation angle was 0 degree and the hole compound angle was 45 degree in the other reference configuration. The results show that compared with the reference configuration with 0 degree main flow orientation angle and 0 degree hole compound angle, the film cooling effectiveness of the configuration with 45 degree orientation angle is more uniform and its average cooling effectiveness is higher; compared with the reference configuration with 45 degree compound angle, the average cooling effectiveness of the configuration with 45 degree orientation angle is lower in the region near the holes but higher in the region far away from the holes. Numerical simulations were also conducted when blowing ratios were 0.5 and 1.5. It is found that the distributions of film cooling effectiveness in the three flow configurations are obviously different from each other. So it is necessary to further investigate numerically and experimentally the effect of main flow orientation angle on the film cooling.