Effect of fin geometry on flow and heat transfer in wedge-shaped ducts: a numerical approach

Abstract Effective cooling of turbine blade trailing edges requires maximizing heat transfer while minimizing hydraulic losses. Conventional circular pin fins, though widely used, create large wakes and high flow resistance. In contrast, leaf slot pin fins, with streamlined shapes, can reduce wake formation, improve flow mixing, and enhance thermo-hydraulic efficiency. This study numerically analyzes flow and heat transfer in a wedge-shaped trailing edge channel with staggered arrays of circular and leaf slot fins over Reynolds numbers from 10,000 to 80,000, using 12 mm fins. Results show Nusselt number rises with Reynolds number for both cases, with leaf slot fins achieving 3–6 % higher values due to stronger mixing. The friction factor decreases with Reynolds number, but leaf slot fins provide 36–52 % lower losses. Although thermal performance factor declines with Reynolds number, leaf slot fins sustain a 22–35 % advantage. Overall, they offer superior cooling efficiency compared to circular fins.