关键词: 双层壁冷却结构, 涡轮叶片, 前缘冷却, 综合冷却效率, 冷却布局优化, 气动性能

Abstract: With the continuous elevation of turbine inlet temperatures, efficient cooling is paramount for structural integrity. Double-wall cooling configurations, leveraging the synergistic mechanisms of internal impingement and external film cooling, have emerged as a pivotal solution. However, due to the inherent geometric complexity, existing studies predominantly focus on flat-plate models or low-speed flow regimes, which fail to capture the complex fluid-thermal characteristics under transonic conditions. In this study, a conjugate heat transfer (CHT) numerical model incorporating typical double-wall structures is developed based on the GE-E3 high-pressure turbine (HPT) first-stage vane. Following aerodynamic profile optimization, the spatial distribution and inclination angles of the film holes were optimized. To validate the numerical framework and evaluate the optimization strategies, a transonic linear cascade experimental platform was established to measure the total pressure loss coefficient and overall cooling efficiency . The results demonstrate that the optimized airfoil profile effectively suppresses passage vortex development, yielding a 9.49% relative reduction in the total pressure loss coefficient. Furthermore, the optimized double-wall layout enhances coolant coverage and thermal protection on the external surface while simultaneously intensifying internal impingement heat transfer. Specifically, the optimized configuration achieves a significant improvement in local overall cooling efficiency near the forward cavity and maintains the area-averaged overall cooling efficiency while reducing coolant mass flow by 5%. The underlying mechanisms for these aerodynamic and thermal performance enhancements are further elucidated through the validated CFD methodology.

Key words: Double-wall cooling structure, Turbine blade, Leading edge cooling, Overall cooling efficiency, Optimization of cooling structure layout, Aerodynamic performance