关键词: 涡轮叶片;热效率;薄膜冷却;气体冷却;喷流试验

Abstract: The paper reports on a detailed experimental study on flow and heat transfer in thedownstream of a cone-shaped film cooling hole with a mainstream. The jet hole with a cone-shapedapex angle of 15° or 30° was oriented so that its angle with respect to the test surface is 30°.Thelongitudinal velocity contours in the boundary layer at the downstream of cone-shaped exit have threebasic forms.Compared with circular jet,the ability of jet penetrating into mainstream and the velocityof jet cores were decreased obviously by increasinng area of jet exit, in the meantime, the lateralcovered region of jet becomes wider, and the strength of vortex is decreased. The cone-shaped holeappreciably increases the spreading of jet and decreases the strength of longitudinal vortex so that thefilm cooling effectiveness at positions laterally displaced from the centerlinne of the hole would bemuch greater than that found downstream of a circular hole. The shaped hole jet produces a successfulCoanda effect at the exit in the high blowing ratio and big cone apex angle so that it would results inhigh effectiveness.

Key words: Turbinne blade;Thermal efficiency;Film cooling;Gas coolinng;Jet test