涡轮静叶复合角度气膜冷却孔排布置优化的数值研究

Numerical Study on Compound Angle Film Cooling Holes Optimized Arrangement of Turbine Stator Blade

采用Realizable k-ε两方程模型,通过改变射流入射角度和吹风比,对具有8排复合角度射流孔的涡轮静叶片表面温度场进行数值研究,确定各个孔排的最佳吹风比;对复合角度孔排的布置进行调整,得到较好的气膜冷却方案。结果表明:在相同的吹风比下,气膜有效覆盖范围随入射角α的减小而增大,展向倾角β的引入可增大气膜展向的覆盖范围;在大吹风比下,角度为α=30°、β=45°时,气膜贴壁性较好,角度为α=60°(α=45°)、β=45°时,压力面前半部气膜出现脱壁现象;在滞止线两侧采用单一角度叉排对吹式孔排布置可对前缘形成更有效的气膜保护。

Realizable k -ε two equation model is applied to simulate temperature field of turbine stator with＇eight rows of compound angle jet holes. Analyzing different jet angles and blowing ratios, to obtain optimum blowing ratio of each row, then rearranging compound holes to obtain better film cooling performance. The results reveal that film effective coverage increased with decreasing angle a at the same blowing ratio, span wise angle β introduced can enlarge the span-wise film coverage. At high blowing ratio, cooling film adheres wall better when jet angles are α = 30° β = 45°, whereas cooling film is off-wall at front half of pressure surface when jet angles are α= 60° （ α= 45°） ,β= 45°. Single angle cross-rows configuration between stagnation line sides adopted can protect leading edge better.