Enhanced Thermal–Hydraulic Performance in Gas Turbine Blade Internal Cooling Channels Using Non-Conventional Features at Ultra-High Reynolds Numbers

Abstract

Abstract. This study presents a detailed numerical and experimental investigation of the thermal–hydraulic performance of three innovative surface-feature configurations in a single-pass cooling channel: Continuous Chevron Pattern Fins (CCPF), Broken Chevron Pattern Fins (BCPF), and V-shaped Double Broken Ribs (VSDBR). High-resolution Reynolds-Averaged Navier–Stokes (RANS) simulations employing the Realizable k–ε turbulence model, validated with experimental data for the VSDBR, covered a Reynolds number range of 100,000–600,000—typical of land-based turbine mid-core flows. Results indicate that thermal–hydraulic performance (THP) declines with increasing Reynolds number, aligning with known trends at lower Re due to increased turbulence and frictional losses. The VSDBR configuration showed the highest heat-transfer improvement (Nu/Nu0 ≈ 2.01 at Re = 100 k) but also the highest pressure drop (f/f0 ≈ 4.4). Conversely, BCPF demonstrated lower thermal enhancement (Nu/Nu0 ≈ 1.22) but significantly lower pressure losses (f/f0 ≈ 2.83 at Re = 100 k). Overall, the VSDBR was the most effective for optimizing THP, as the heat-transfer benefits from the ribs substantially outweighed the pressure penalty compared to fin designs. Nonetheless, BCPF illustrates that features aimed at reducing pressure losses while maintaining moderate heat transfer can improve THP, especially at high Reynolds numbers. These findings emphasize the importance of designing rib–fin geometries that perform effectively across different Re regimes. The study enhances current understanding by examining the thermal-fluid dynamics of complex internal cooling features under conditions representative of actual engine operation at high Reynolds numbers, offering valuable insights for the development of next-generation turbine blade cooling technologies.