Numerical simulation of composite swirl/film double-wall cooling structures and chamber designs for enhanced overall cooling effectiveness: II. Improvement with serpentine chamber and application in C3X vane

• A serpentine swirl/film double wall cooling structure is proposed for turbine vanes. • The new structure provides greater cooling benefits than the film/impingement DWC structure. • Area-averaged cooling effectiveness is improved by 6.74 %-7.90 % at blowing ratios of 0.50-2.00. • Cooling effectiveness and energy loss coefficient rise by 3.80 %-4.39 % and 0.37 %-0.55 % for vanes. • It exhibits superior temperature uniformity, reduced deformation and improved vane stability. Double wall cooling is a viable option for future gas turbine cooling technology. To improve the applicability of turbine vanes, this study improves the composite swirl/film double wall cooling structure proposed in our previous work, and forms a novel serpentine swirl/film double wall cooling structure specifically used for turbine vanes. Through numerical simulation, the cooling characteristics, flow field structure and energy loss of the new cooling scheme at various blowing ratios in plate and vane models are investigated and compared with the traditional film/impingement double wall cooling structure. The results show that the new double wall cooling design provides greater cooling benefits. The new cooling structure has an area-averaged overall cooling effectiveness of 6.74 %-7.90 % higher than the traditional double wall cooling structure within blowing ratios of 0.50-2.00. When the new structure is applied to the vane model, it can also improve the effectiveness by 3.80 %-4.39 % compared with the traditional double wall cooling structure, and the energy loss coefficient increases only by 0.37 %-0.55 %. The results also show that due to the improvement of temperature uniformity by the new cooling structure, the vane deformation is reduced, and the stability and safety of the vane are improved. The proposed cooling structure is expected to provide new ideas for future gas turbine cooling design.