涡轮叶片厚壁带肋通道冷却性能的实验研究

Experimental Study on the Cooling Performance of Thick-Wall Ribbed Channels in Turbine Blade

基于10种不同结构空气冷却厚壁带肋通道的实验数据,分析了宽高比(0.25~4)、肋角(30°~90°)和雷诺数(10000~60000)对带肋通道流动及传热性能的综合影响,拟合得到了通道摩擦系数和壁面平均努塞尔数关于宽高比、肋角和进口雷诺数的经验关联式。结果表明:厚壁带肋通道摩擦系数随着宽高比和肋角的增大均大致呈现出升高的变化趋势;平均努塞尔数和综合热力系数随肋角的增大均表现为先增大后减小的分布趋势,随宽高比的增大表现为先增大后减小、再增大再减小的分布趋势。不同雷诺数时,壁面平均努塞尔数的最大值都大致出现在宽高比为1.75~2.75、肋角为55°~65°之间;最高的综合热力系数出现在宽高比约为0.75和2、肋角约为60°时。平均努塞尔数关联式的平均拟合偏差为6.96%,摩擦系数关联式的平均拟合偏差为12.75%。本文研究结果可为未来重型燃机叶片冷却结构设计提供参考。

Based on the experimental data of 10 air-cooled thick-wall ribbed channels with different structures,the comprehensive effects of channel aspect ratio(0.25-4),rib angle(30°-90°)and Reynolds number(10000-60000)on the flow and heat transfer performance of ribbed channels were analyzed.The empirical correlations about the channel friction coefficient and the average Nusselt number related to channel aspect ratio,rib angle and Reynolds number were fitted.The results show that the friction coefficient of the thick-walled ribbed channels increases with the increase of channel aspect ratio and rib angle.The average Nusselt number and comprehensive thermal coefficient both increase first and then decrease with the rib angle,and both have a fluctuating trend of increasing first,decreasing second,then increasing again and final decreasing with the increase of channel aspect ratio.At different Reynolds numbers,the maximum value of average Nusselt number occurs approximately at the channel aspect ratio of 1.75-2.75 and rib angle of 55°-65°.The highest comprehensive thermal coefficient occurs when the channel aspect ratio is about 0.75 and 2,and the rib angle is about 60°.The mean fitting deviation of the average Nusselt number correlation is 6.96%,and the mean fitting deviation of the friction coefficient correlation is 12.75%.The results may provide references for the cooling structure design of advanced gas turbine blade in the future.