曲率对旋转态气膜冷却效率影响的数值模拟

通过对旋转状态下曲率叶片模型上气膜冷却现象的流动和换热进行数值模拟,得到了不同主流雷诺数、吹风比和旋转数情况下吸力面和压力面上的冷却效率分布.计算选用κ-ω和SST(Shear-Stress Transport)湍流模型,主流雷诺数Re=3 198.4~6 716.6,吹风比M=0.2~1.2,旋转数Rt=0~0.015 9.结果表明:旋转数的增大导致气膜孔下游中心区域的冷却效率下降,但使压力面整场的冷却效果略有提高;吹风比的增大使得吸力面和压力面上的冷却效率逐渐降低,主流雷诺数的变化对壁面整体冷却效果则影响不大.此外,相同工况下吸力面上的冷却效率要高于压力面上的对应值.

Numerical simulation of film cooling effectiveness on rotating curvature models

Computations were performed to investigate the adiabatic effectiveness η distributions on the curvature turbine blade models under rotating conditions. In the present study, the Reynolds number Re based on mainstream velocity and film hole diameter varies from 3198.4 to 6716.6, the blowing ratio M ranges of 0.2 to 1.2, and the rotation number Rt alters from 0 to 0. 015 9. Both κ-ω and the shear-stress transport (SST) models were chosen for turbulence closure. Results show that the increase of Rt leads to decreased η values in the centerline region downstream the film hole, but can improve the integrated effectiveness properly on the pressure surface. The augmentation of M also results in the decreased adiabatic effectiveness, while the variation of Re has little influence on the comprehensive cooling effect. In addition, the values of η on the suc-tion surface are much greater than that on the pressure surface under the same operating conditions.