平板孤立冷却孔下游换热特性实验

Experiments on Heat Transfer Performance Downstream of the Single Cooling Hole in a Flat Plate

关键词:  实验研究  稳态液晶  气膜冷却

Key words:  Experimental study  Liquid crystal  Film cooling

摘要:

为了考察弯曲冷却孔通道对气膜冷却的影响,运用稳态液晶测温技术,对处于横向流中平板孤立圆形直孔和圆形弯曲孔下游的换热特性进行了实验研究。得到了吹风比为0.51、0.8、1.04、1.22下,冷却孔下游附近的冷却效率分布和传热系数的二维分布。实验结果证明:弯曲射流能够有效地提高下游的冷却效率,并且能使气膜具有较强的横向扩展能力, 覆盖效果好。但由于其对主流有较强的扰动,所以会增加当地的局部传热系数。 

Abstract:

In order to investigate the influence of curved passage on film cooling, the heat transfer performance downstream of single straight and curved cooling holes was studied experimentally by using the thermochromic liquid crystal technique. The 2D distribution of cooling effectiveness and the heat transfer coefficient downstream of the cooling hole at the blowing ratios 0.1,0.8,0.4,1.22,respectively, were investigated. The measurements reveal that the curved injection can increase the cooling effectiveness, and the cooling film has wider transverse expansion with the better coverage. However, the local heat transfer will be elevated due to the stronger disturbance of curve injection.