Numerical research of a new pipe network cooling scheme without film holes for the gas turbine blade mid-chord region

Abstract

To explore new efficient cooling technology for advanced gas turbine blades and reduce dependence on film cooling, this paper proposes a novel pipe network cooling structure. The design connects leading-edge impingement cooling holes to trailing-edge slits through lateral pipes and incorporates independent vertical pipes to form a network structure. This cooling structure can be applied to a complete blade cooling system, demonstrating strong cooling performance in the mid-chord region despite the absence of film holes, while achieving a more uniform overall temperature distribution, showing promising developmental potential. Through experimental and numerical simulations, comparisons were made with typical gas turbine blade cooling structures and double-wall cooling structures. The results indicate that this new pipes network cooling structure offers superior cooling performance and achieves a more uniform temperature distribution. In addition, the study investigated the impact of lateral pipes shapes and the distances between transverse and vertical pipes relative to the end wall on cooling performance. The results showed that, under the same boundary conditions, hexagonal pipes performed better. The relative positions of transverse and vertical pipes significantly affected blade cooling efficiency. P₁/P₂ = 0.5, the temperature distribution was the most uniform; P₁/P₂ = 1, heat transfer in the mid-chord region improved.