化工燃气轮机动叶全表面气膜冷却影响的数值模拟

Numerical Simulation of Unsteady Wakes' Effect on Film Cooling of Rotor Blade Surface

对非定常环境下燃气轮机动叶全表面气膜冷却流场进行数值模拟,应用标准k-ε两方程紊流模型和SIMPLE算法,用直径6mm的圆柱模拟静叶,使圆柱产生尾迹,研究不同吹风比时尾迹对下游动叶全表面冷却效率和传热特性的影响。结果表明:圆柱尾迹产生漩涡,漩涡会导致熵增,使动叶全表面能量有损失。吹风比M=0.5时,射流孔处冷却效果较好,动叶整个表面冷却效率较低,表面传热也较差;吹风比M=1.5时,射流孔处冷却效率降低,而整个表面冷却效率增加,传热增强。

The surface film cooling field of the turbine blade in unsteady environment was simulated. Through making use of standard k-e two equations turbulence model and SIMPLE algorithm and employing 6mm-column （ d ） to simulate static blades so as to generate unsteady wakes, the unsteady wake＇ s effect at different blowing ratio on the rotor blade ＇ s cooling efficiency and heat-transfer characteristic was investigated to show that, the column＇s wake leads to vortex which can lead to entropy production and bring energy loss to the rotor blade surface ; when blowing ratio M stays atO, 5, the cooling effect at the cooling holes becomes better and the cool- ing efficiency on the rotor blade surface drops along with a poor surface heat transmission; when blowing ratio M is 1.5, cooling efficiency at cooling holes becomes decreased but that on rotor blade surface gets enhanced, including the heat transmission.