论文部分内容阅读
基于有限体积法对三维定常不可压缩N-S方程进行离散,采用两层k-ε湍流模型,在吹风比M为0.6,1.2和1.8的情况下,数值研究了6种不同横向槽结构对气膜冷却效果的影响,并与常规圆柱孔进行了比较。结果表明:在任何吹风比下,所有开槽孔的冷却效率均高于圆柱孔;在低吹风比时,6种开槽孔的冷却效率相差不大,随着吹风比的增大,不同开槽孔冷却效率的变化趋势不尽相同;具有中等开槽深度(0.75D)和最大开槽宽度(3D)的开槽孔,气膜冷却效果最佳,而具有最大开槽深度(1D)的开槽孔,气膜冷却效果较差;横向槽的存在使冷气射流在流出气膜后面积突扩,动量降低,气膜出流向主流的垂直穿透能力随之降低,射流本身流动的扩散以及射流在流入横向槽中受到主流对其向下的压制作用较大,反向涡旋对的强度不同程度地受到了抑制,增强了壁面的冷却效果。
Based on the finite volume method, the three-dimensional steady incompressible Navier-Stokes equations are discretized. The two-layer k-ε turbulence model is used. When the blow ratio M is 0.6, 1.2 and 1.8, Effect of the effect, and compared with the conventional cylindrical hole. The results show that the cooling efficiency of all the slotted holes is higher than that of the cylindrical holes at any blowing ratio, while the cooling efficiency of the six slotted holes is not different at low blowing ratio. As the blowing ratio increases, Slot cooling efficiency trends vary; Slotted holes with a medium depth of cut (0.75D) and a maximum width of cut (3D) have the best film cooling effect and the maximum depth of cut (1D) Slotted holes, the film cooling effect is poor; the presence of lateral grooves so that air jets in the outflow of film after the sudden expansion of area, lower momentum, the film out of the mainstream to the vertical penetration decreases, the flow of the proliferation of jet itself and The jet impacted by the mainstream in the inflow transverse groove greatly presses downwards, and the strength of the reverse vortex pair is suppressed to some extent and the wall cooling effect is enhanced.