旋转状态下曲率对叶片气膜冷却特性的影响

Numerical simulation on film cooling performance of blades with different radius of curvatures in rotating state

采用SSTk-ω紊流模型模拟旋转状态下4种曲率半径(R/D=30,R/D=75,R/D=120和R/D=∞)叶片的气膜冷却效果。分析讨论吹风比分别为0.5和1.5,旋转数分别为0.037 68,0.075 36及0.113 04时,曲率和旋转数对叶片吸力面和压力面气膜冷却特性的影响。结果表明:旋转数一定时,曲率半径越小叶片的吸力面和压力面气膜轨迹偏转越明显;当曲率半径变大时,吸力面高Nu区域面积增大,叶片表面传热效果增强;压力面高Nu区域面积减小,叶片压力面气膜冷却效果减弱;旋转数的增大使得小曲率半径叶片吸力面表面传热减弱,大曲率半径叶片的压力面表面传热降低。

The turbulence model was employed to simulate film cooling effect of blade with four radius of curvatures in rotating state.The effects of curvature and rotating number on film cooling performance of the convex surfaces and concave surfaces was investigated,under conditions with blowing ratio of 0.5 and 1.5,and the rotating number of 0.037 68,0.075 36 and 0.1 13 04.The results show that,with a constant rotating number,the lower the radius of curvature,the more obvious the gas film deflection of the convex surfaces and concave surfaces.Increasing the radius of curvature will enlarge the area of convex surface with high Nu number and enhance the heat transfer,while the concave surfaces had the opposite results.In addition,increasing the rotating number will weaken the heat transfer on convex surfaces with low radius of curvature and that on concave surfaces with high radius of curvature.