涡轮导叶W型孔全气膜冷却效率实验研究

In order to study the full coverage film cooling effectiveness of the turbine guide vane with W-shaped holes, the film cooling effectiveness of a three-dimensional turbine guide vane with W-shaped holes was measured using transient liquid crystal technique. The flow rate ratios are 5.5%, 8.4% and 12.5%, and the mainstream turbulence intensities are 1%, 9% and 15%. In addition, the results were compared with those of the cylindrical hole full coverage film cooling vane under the same conditions. The results show that at low turbulence intensity condition, the effects of the flow rate ratio on the film cooling effectiveness are different in different regions of the W-shaped hole vane. At high turbulence intensity condition, the increase of flow rate ratio generally increases the film cooling effectiveness of the W-shaped hole vane. At all the mass flow rate ratio conditions studied in this paper, the film cooling effectiveness of the W-shaped hole vane decreases with increasing the turbulence intensity. Compared with the cylindrical hole vane, at low and middle turbulence intensities, the coolant from the W-shaped holes has a better attachment and spanwise coverage to the vane surface, which makes the W-shaped hole vane have more advantage in film cooling effectiveness. However, at high turbulence intensity condition, the coolant from the W-shaped hole is more dispersive and has lower speed, so the coolant is easy to dissipate dramatically, which reduces the advantage of W-shaped hole vane. Even more, the area-averaged film cooling effectiveness of the cylindrical hole vane is about 15 % higher than that of the W-shaped hole vane at high turbulence intensity and high flow rate ratio condition.