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(10 000-60 000)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.
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references
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