冲击发散冷却流场结构PIV测量

为了研究冲击发散冷却结构的流场特性,设计了一典型冲击发散冷却结构,采用粒子图像测速仪(PIV)对其流场特性进行了研究.研究发现,在冲击板与发散孔板间,气流的流动状态很复杂,在各个方向上均形成大量的涡,且涡的形式和强度均随吹风比的变化而变化.在发散气膜侧,随着吹风比的增大,由发散孔流出的冷却气流会逐渐穿透主流,从而使得冷却气膜层愈来愈不稳定,脱离壁面;而在发散孔出口与主流方向垂直的位置会形成一对旋转方向相反的肾形涡,且涡的位置随吹风比的增大而移向主流区域. 

PIV measurement of flow field for impingement-effusion cooling

In order to study the flow field characteristics of impingement-effusion cooling,a kind of impingement-effusion cooling structure was designed,the flow field characteristics of it was studied by PIV(particle image velocimetry).It was found that the flow characteristics between impingement plate and effusion plate is very complex,and the size of eddy between impingement plate and effusion plate is different with the change of blowing ratio.On the side of effusion film,the flow from effusion hole will penetrate gradually main flow when blowing ratio is increased,that destroys the effusion film.There is a pair of "kidney eddies" on the vertical section of the outlet of effusion hole,and the "kidney eddies" will moves into the main flow when the blowing ratio is increased.