沉积环境下涡轮叶片前缘气膜冷却的实验研究

为研究沉积物对涡轮叶片前缘气膜冷却的影响，实验采用石蜡沉积模拟真实沉积。通过改变主流的温度、气膜孔射流角度及气膜孔孔径，观察了沉积环境下气膜冷却效率及沉积率的变化规律。实验结果表明:颗粒物沉积在障碍物表面的形貌受到主流温度的影响较大，当主流温度接近颗粒物熔点时，沉积覆盖最明显。在相同实验条件下，随着射流角度增大，单个气膜孔覆盖区域减小，气膜冷却效率下降，沉积前后，射流角度25°和65°的气膜冷却效率最大相差2%和5.6%，沉积率随射流角度的增大而升高；随着孔径增大，气膜冷却效率先降低后升高，其中4.5 mm孔径无论是否沉积，气膜冷却效率均最高，比3 mm孔径的气膜冷却效率高3.6%和3.2%。沉积率在孔径3 mm时最低。 

Experimental study on film cooling of turbine blade leading edge in deposition environment

In order to study the effect of deposition of pollutants on film cooling of blade leading edge of turbine, the experiment used paraffin deposition to simulate real deposits.By changing the mainstream temperature, the angle of film hole jet and the diameter of film hole, the variation of film cooling efficiency and deposition rate in deposition environment was observed experimentally. The experimental results show that the morphology of particulate deposition on the barrier surface is significantly affected by the mainstream temperature. When the mainstream temperature approaches the melting point of particulate matter, the deposition coverage is most obvious. Under the same experimental conditions, with the increase of jet angle, the coverage area of single film hole decreases, and the film cooling efficiency decreases. Before and after deposition, the maximum difference between film cooling efficiency at jet angle 25° and jet angle 65° is 2% and 5.6%, and deposition rate increases with the increase of jet angle; with the increase of pore diameter, the film cooling efficiency first decreases and then increases. Whether there is deposition or not, the film cooling efficiency of 4.5 mm pore diameter is the highest, 3.6% and 3.2% higher than that of 3 mm pore diameter. The deposition rate is the lowest when the pore diameter is 3 mm.