Enhancing Heat Transfer in Turbine Blade Cooling Channels Using Perforated V-Shaped Ribs: A CFD Study

Abstract

This study numerically investigates the thermal and hydraulic performance of square cooling channels fitted with V-shaped ribs, emphasizing the effect of rib perforations. Three configurations were examined: solid V-ribs (VR), circular-perforated V-ribs (CPV), and semi-circular-perforated V-ribs (SCPV), each incorporating one to three holes. Simulations were conducted for Reynolds numbers between 5,000 and 15,000 using a three-dimensional, steady-state, incompressible flow model with the RNG-𝑘𝜀 turbulence model. Performance was evaluated through local Nusselt number distributions, Nu/Nu0, friction factor ratio ( 𝑓 / 𝑓0), and thermal enhancement factor (TEF). Results indicate that rib perforations reduce recirculation zones and improve fluid mixing, producing more uniform wall heat transfer. Compared with solid ribs, perforated designs consistently achieve higher Nusselt numbers and TEF values, with semi-circular perforations showing slightly superior performance to circular ones. Additionally, perforations help limit frictional penalties typically associated with rib turbulators, especially when multiple holes are used. Overall, rib perforation emerges as an effective approach for enhancing heat transfer while controlling flow resistance in turbine blade internal cooling.