Heat Transfer and Fluid Flow Analysis in a Square Ribbed Channel at High Reynolds Numbers for Gas Turbine Blade Cooling: A Numerical Approach

Abstract In this study, the heat transfer and frictional characteristics of four novel rib configurations, namely, broken V rib, double broken V rib, broken V rib with fins, and V-shaped fin array were numerically investigated on a high Reynolds number internal cooling channel. The rib geometries were positioned at a 45 deg angle to the flow, with a rib pitch-to-height ratio (p/e) of 16 and a rib height-to-hydraulic diameter ratio (e/Dh) of 1/20. High Reynolds numbers ranging from 100,000 to 400,000 were studied to evaluate the performance of these rib configurations. Computational fluid dynamics (CFD) simulations were performed using the k-ε RNG turbulence model in ansys fluent. The heat transfer and flow characteristics were analyzed to understand the interaction between rib-induced secondary flows and their effect on heat transfer enhancement. The broken V rib configuration exhibited a 26% higher heat transfer rate compared to W-shaped ribs in reference and a 59% improvement over rib with fin configurations. In addition to its enhanced heat transfer performance, the broken V rib configuration maintained low frictional losses, making it the most thermally efficient design. The double broken V rib and rib with fin configurations showed moderate heat transfer performance but showed higher pressure penalties. Overall, the broken V rib was identified as the most effective for internal cooling in gas turbine applications, providing an optimal balance between heat transfer enhancement and frictional losses operating particularly at the high Reynolds number condition for turbine blade mid-core passages.