导流片结构参数对缩扩蜿蜒通道流阻及换热性能影响

Influence of Deflector Structure Parameters on Flow Resistance and Heat Transfer Performance of Constricted and Expanded Serpentine Channel

为改进涡轮叶片内冷通道流动换热性能,数值模拟研究入口雷诺数2×10^(4)~8×10^(4)时缩扩蜿蜒通道内导流片结构、布置方式和几何尺寸对流阻和换热性能影响,获得二次流强度和综合热力性能之间的关系。结果表明:随着雷诺数增加,带导流片通道阻力系数变化幅度小于5%,180°导流片拥有各模型中最强减阻能力,导流片通道阻力系数相较于无导流片通道下降50.2%。导流片结构起到强化换热作用,180°导流片强化换热效果最显著,换热系数提高12.3%。导流片不同结构对通道综合热力性能影响差别较大,180°导流片通道综合热力性能最强,相较于无导流片通道提升56.4%。综上所述,导流片结构参数方面研究可以有效降低内冷通道流动阻力损失并增强其换热能力。

In order to improve the flow and heat transfer performance of cold channels in turbine blades,the effects of the structure,arrangement form and geometric dimensioning of the deflector on the flow resistance and heat transfer performance in the constricted and expanded serpentine channel at the inlet Reynolds number of 2×10^(4)~8×10^(4)were investigated by numerical simulation,and the relationship between secondary flow intensity and thermal performance factor was obtained.The results show that with the increase of Reynolds number,the change range of drag coefficient of the channel with deflector is less than 5%.The 180°deflector has the strongest drag reduction ability among all models,and the drag coefficient of the channel with deflector decreases by 50.2%compared with that without deflector.The deflector structure plays an enhanced role in heat transfer,the 180°deflector has the most significant enhanced heat transfer effect,increasing the heat transfer coefficient by 12.3%.Different structures of the deflector have a great influence on the thermal performance factor of the channel,and the thermal performance factor of the 180°deflector channel is the strongest,which is 56.4%higher than that of the channel without deflector.In summary,the study of the structural parameters of the deflector can effectively reduce the flow resistance loss of the cold channel and enhance its heat transfer capacity.