To improve the convective heat transfer in internal cooling channels of heavy-duty gas turbine blades, this study experimentally and numerically investigates the thermal performance of rectangular channels with hybrid pin-fins and micro V-ribs turbulators. The transient thermochromic liquid crystal (TLC) technique and ANSYS 2019 R3 (ICEM CFD 2019 R3, Fluent 2019 R3, CFD-Post 2019 R3) were employed under Reynolds numbers ranging from 10,000 to 50,000, with the numerical model rigorously validated against experimental data (the maximum RMSE is 2.5%). It is found that hybrid pin-fins and continuous V-ribs configuration exhibits the maximum heat transfer enhancement of 27.6%, with an average friction factor increase of 13.3% and 21.9% improvement in thermal performance factor (TPF) compared to the baseline pin-fin channel. In addition, compared to the baseline pin-fin channel, hybrid pin-fins and broken V-ribs configuration exhibits average heat transfer enhancement (Nu/Nu0) of 24.4%, an average friction factor increase of 7.2% and 22.5% improvement across the investigated Reynolds number range (10,000~50,000) based on computational results. The synergistic effects of hybrid pin-fin and micro V-rib structures demonstrate superior coolant flow control, offering a promising solution for next-generation turbine blade cooling designs. This work provides actionable insights for high-efficiency gas turbine thermal management.

In order to obtain high-efficiency heat transfer for heavy-duty gas turbines, the internal enhanced composite cooling of turbine blades has been investigated. The results of transient liquid crystal experiments indicate that as the Reynolds number increases, both continuous V-rib and broken V-rib exhibit stronger heat transfer performance, with the average heat transfer effect of continuous V-rib surpassing that of intermittent V-rib by approximately 6.4%. Subsequently, four V-rib structures including continuous, broken, and staggered configurations were analyzed using numerical simulation methods to demonstrate local three-dimensional turbulence characteristics and reveal the impact of V-rib parameter variations on heat transfer performance. The findings suggest that continuous V-rib exhibits superior Nusselt number, flow resistance, and comprehensive heat transfer performance compared to broken V-rib; while staggered V-rib demonstrates the highest flow resistance.