Optimal design on double-wall cooling structures by density-based topology optimization for turbine blades

Double-wall cooling is an advanced method applied to the next generation of turbine blades. Traditional design and optimization methods within predefined parameter spaces often struggle to fully exploit the potential of double-wall cooling structures. This study utilizes a density-based topology optimization approach with weighted objectives of temperature, pressure loss, and temperature gradient for optimizing pin-fin structures within the double-wall. To mitigate the influence of initial values, four typical double-wall structures are employed as initial designs. Multi-objective topology optimization converges to distinct optimal pin-fin configurations for different initial double-wall designs. The final topology-optimized structures are then compared with the initial structures and parameter-optimized structures with the same filling ratio. Results indicate that the “161” structure (impingement holes: pin-fins: film cooling holes = 1:6:1) as an initial design yields topology-optimized structures with superior temperature reduction and uniformity, demonstrating the best overall performance among all structures. This study reveals the impact of initial designs on topology optimization outcomes, identifying the “161” structure as a superior initial design. The approach presented in this paper demonstrates the potential of topology optimization in designing high-performance double-wall cooling structures.