C3X涡轮叶片综合冷却效率数值研究

Numerical Study on Overall Cooling Effectiveness of C3X Turbine Blade

燃气轮机叶片综合冷却效率实验中,实验工况与实际运行工况不一致,使应用实验结果的叶片设计出现偏差,从而达不到预期冷却效果。根据一维公式提出的理论选取对综合冷却效率造成影响的参数。通过研究不同参数下C3X叶片综合冷却效率的变化情况,量化选取的参数对综合冷却效率的影响,得到了毕渥数、粗糙度对叶片综合冷却效率的影响规律。研究结果表明:随着叶片外表面毕渥数增加,综合冷却效率分布均匀性增加。当Bi由0.023227增加至0.023252,Bi增加幅度0.11%时,平均综合冷却效率由0.324增加至0.357,综合冷却效率增加幅度为10.2%。在实验工况范围内,当Ks由0.8 mm增加至3.0 mm,平均综合冷却效率由0.34增加至0.37,综合冷却效率增加幅度为8.82%。

In the overall cooling effectiveness experiment of gas turbine blades, the experimental conditions are different from the actual operating conditions. This leads to deviation in the blade which applied experimental results, and thus fails to achieve the expected cooling effectiveness. According to the theory of one-dimensional formula, the parameters affecting the overall cooling effectiveness are selected. By studying the changes of overall cooling effectiveness of C3x blades under different parameters and quantifying the influence of selected parameters on overall cooling effectiveness, the influence laws of Biot number and roughness on overall cooling effectiveness of blades are obtained. The results show that the distribution uniformity of overall cooling effectiveness increases with the increase of the Biot number on the outer surface of the blade. When it increases from 0.023227 to 0.023252 by 0.11%, the average overall cooling effectiveness increases from 0.324 to 0.357, and the overall cooling effectiveness increases by 10.2%. In the range of experimental conditions, when KS increases from 0.8 mm to 3.0 mm, the average overall cooling effectiveness increases from 0.34 to 0.37, and the increased range of overall cooling effectiveness is 8.82%.