Heat transfer enhancement by employing inserted plate in turbine blade internal cooling channel

Abstract

A novel method by employing an inserted plate in turbine blades internal cooling channel is presented for the first time in this study, which can extend cold surfaces for radiation and therefore enhance total heat transfer and improve heat transfer uniformity. The coupled convective and radiative heat transfer in the rotating channel is numerically explored. The mechanisms of heat transfer enhancement are revealed by analyzing the flow and heat transfer for five channel models. Influences of the thermal conductivity and the thickness of the inserted plate, as well as pertinent parameters including the Reynolds number, the rotation number, and the wall heat flux are also investigated. The results indicate that, comparing the novel model (Model 2B) which inserts the plate parallel to the leading and trailing walls and considers radiation with the existing model (Model 1A) which doesn't insert the plate and consider radiation, the total Nusselt number ratio and the performance evaluation criterion increase by 73.77% and 23.77%, respectively. Besides, the maximum and average temperature dramatically decrease by 209.05K and 77.87K, respectively. The heat transfer difference between the leading and trailing walls caused by the Coriolis force is significantly reduced. And the self-enhancement effect of this method is demonstrated.

Keywords

• Turbine blades internal cooling
• Inserted plate
• Coupled convective and radiative heat transfer
• Self-enhancement effect
• Rotation