Thermal performance enhancement for gas turbine blade trailing edge cooling with topology-optimized printable diamond TPMS lattice

•Turbine blade trailing edge internal cooling is designed using topology optimization and TPMS.•Topology-optimized model significantly improves flow field and heat transfer performance.•Proposed design is printed by powder bed fusion via Inconel718 to study manufacturability. The gas turbine blade trailing edge region is a critical concern in the cooling design due to its narrow characteristics, which limit the implementation of cooling structures. With rapid development in additive manufacturing, many complex cooling techniques have been designed to enhance thermal performance and improve flow uniformity for gas turbine blade trailing edges. This study generates a high thermal performance cooling structure for the trailing edge channel using topology optimization and a Diamond-type triply periodic minimal surface (TPMS) structure. The optimized model is obtained by infilling the Diamond structure in the intermediate densities from the topology optimization, where the objective is to maximize heat transfer under constant input power. The flow path constraints are also included to achieve better uniform flow distribution. The optimized models are compared with the baseline circular pin fin and uniform Diamond network at Reynolds numbers of 10,000 to 30,000. The results show that the uniform Diamond structure provides obviously higher heat transfer than the pin fins by up to 314.3 %. The optimized models obtain lower heat transfer but considerably reduce pressure loss by about twice compared to the uniform Diamond case. Even though the pressure loss of the optimized model is higher than in the pin fins, the thermal performance enhancement is increased by 139.7 %–150.2 %. The fluid flow and heat transfer in the optimized model are distributed more uniformly than in the pin fins. Furthermore, a high-resolution CT scan is employed to assess the manufacturability of the proposed design, printed by laser powder bed fusion at a scale of realistic gas turbine blades. The findings show the feasibility of 3D printing for next-generation gas turbine blades.