槽缝射流对静叶端壁冷却性能的影响
Effect of the Slot Jet Impingement on the Cooling Performance of the Vane Endwall

采用数值求解三维RANS方程和k？拨赝牧髂Ｐ？,研究了槽缝射流对涡轮静叶端壁冷却性能的影响;通过对4种湍流模型数值结果与实验数据的比较,验证了标准k？拨赝牧髂Ｐ涂梢杂行？模拟静叶前缘端壁的冷却性能,揭示了槽缝宽度、入射段结构和端壁边界型线对静叶端壁冷却性能的影响规律。研究结果表明:在一定的槽缝射流流量下,减小槽缝宽度能够增大冷却射流的覆盖面积,提高静叶前缘气膜孔排附近区域的冷却效率;过渡相切圆弧的槽缝入射段结构具有最佳的静叶端壁冷却效果。端壁边界型线可改变节距方向上的槽缝冷却射流的流量分配,影响下游端壁的冷却效果,当端壁相对型线幅值为0.75、相位角为30°时,槽缝射流具有最佳的静叶端壁冷却效果。
Effect of the slot jet impingement on the cooling performance of the vane endwall was numerically investigated using three？？dimensional Reynolds？？averaged Navier？？Stokes (RANS) equations and k？拨？ turbulent model. The film cooling effectiveness of the experimental vane endwall was analyzed using four turbulent models. The accuracy of the utilized k？拨？ turbulent model for the cooling performance of the vane endwall was demonstrated by comparison of the experimental data and numerical results with four used turbulent models. The different slot widths, angles and geometrical profiles, as well as the leading contours of the vane endwall were utilized to analyze their effects on the cooling characteristics of the vane endwall. The numerical results show that slot width has great influence on the cooling characteristics of downstream endwall surface, and it achieves better cooling performance on the downstream endwall surface with the decrease of slot width when the slot flowrate ranges within a certain scope. The angle and structure between slot entrance and downstream endwall surface can significantly affect the cooling characteristics of downstream surface. Smaller angle of slot entrance and downstream endwall surface and smoother structure obtain better cooling performance. The optimized slot downstream endwall profile achieves better cooling performance compared with conventional endwall profile because the optimized slot downstream endwall profile can adjust flow rate distribution via changing the geometry along the pitchwise orientation. The endwall geometry profile with non？？dimensional amplitude of 0？？75 and phase angle of 30° achieves optimal cooling performance