Multi-region synergistic improvement and experimental validation of internal and external cooling structures in turbine blades

This study establishes a systematic research framework of “deficiency diagnosis—flow field analysis—structural improvement—experimental validation.” Through numerical simulations, the cooling deficiencies and underlying causes of a turbine blade with complete internal and external cooling structures are analyzed, leading to a hierarchical improvement scheme. The scheme first addresses localized issues with targeted modifications before integrating regional improvements to achieve overall performance enhancement. For internal cooling, multi-hole impingement is applied at the leading edge to eliminate recirculation vortices, 45° angled ribs with reduced spacing are introduced at the mid-chord to enhance flow disturbance, and an impingement baffle is added at the trailing edge to guide coolant for a more uniform heat transfer distribution. For external cooling, cylindrical holes are replaced with fan-shaped holes featuring compound angles, and the film hole layout is redesigned. Numerical simulations indicate that these improvements significantly enhance internal heat transfer uniformity and increase the blade-averaged film cooling effectiveness from 0.146 to 0.277. Experimental validation further demonstrates that, under the same coolant flow rate, the blade's overall cooling effectiveness is improved by 10.9%. These findings provide both theoretical and engineering guidance for turbine blade cooling design.