【摘要】 本文对弯曲通道凸壁面单排孔30°喷射时气膜冷却流场的近场特性作了比较精细的测量,测量的数据包括壁面静压分布、速度矢分布及气膜冷却有效温比分布。测量表明,弯曲通道凸壁面上30°喷射时对流场的干扰,在孔近场区是显著的,在孔下游约一倍孔径的范围内,流向及侧向的压力变化均甚大;而在进一步下游,主流绕流射流所产生的结构复杂的“绕流区”也是明显的.由于壁面曲率的影响,射流贴附壁面的程度,在M<1.0时,要优于平壁;而当M>1.0时,由于射流的“穿透”作用,其附壁程度又劣于平壁.在X/D>10之后,射流产生的扰动已趋衰减,射流的侧向扩散使流场的三维特征逐渐消失,而接近于二维连续缝槽气膜冷却流场的规律.在本试验条件下,M=0.5左右,可以获得最佳的气膜冷却效果。更多还原

【Abstract】 In this paper, the flow fields near the exits of a row of film cooling holes on a convex surface have been measured extensively. The data measured include the wall static pressure distribution, the velocity vector and film cooling effectiveness. The measurements show that the injection process increases disturbances considerably in the vicinity of the holes. Further downstream, the recirculation zone induced by the mainstream around the jets is still strong. Due to the wall curvature, the film jets have better attachment to the wall than flat plate for M < 1.0. For M ≥1.0, however, film jets "separate" from the wall near the injection holes. Far downstream where X/D > 10, the disturbances caused by the jets will decay and the three dimensional features will gradually be diminished because of the lateral diffusion of the jets. The present results suggest that the optimum injection rate is about 0.5.更多还原