3D Heat Transfer Assessment of Full-Scale Inlet Vanes With Surface-Optimized Film Cooling: Part 2 — Conjugate CFD Simulations

Abstract

Abstract An investigation of the experimental heat transfer and cooling effectiveness for a modern fully-cooled high-pressure turbine (HPT) inlet vane is presented. Conjugate Heat Transfer (CHT) Computational Fluid Dynamics (CFD) is conducted to simulate experiments using thin-film heat-flux gauges on full-scale 3D vanes at engine-representative conditions from Part 1 of this paper. Pressure side (PS) film cooling performance is compared for a baseline and optimized configuration, in which the latter was previously developed using genetic algorithm (GA) optimization. The optimized vane was iterated using hundreds of computationally efficient 3D Reynolds Averaged Navier Stokes (RANS) CFD simulations with a transpiration boundary condition to simulate film cooling. This combination of CFD and GAs determined surface-optimized cooling hole orientations and placement. Steady-state flat plate infrared thermography experiments that followed also determined the best cooling hole shapes to use on different sections of the vane pressure side surface. This ultimately generated the cooling design to be fabricated using realistic materials and experimentally tested in Part 1 and simulated using CHT CFD in the current work (Part 2). Here, spanwise and streamwise heat transfer distributions for the baseline and optimized cooling design are validated against experimental data. 3D CHT CFD results are then assessed at the same conditions, providing relevance and credence to the overall cooling design methods. Ultimately, surface-optimized film cooling designs can be used to reduce the adverse effects of sub-optimal heat distribution on critical high temperature engine parts, increasing the life of the part. Alternatively, such a design could lead to increases in engine efficiency since less cooling air is required from the mainstream per part.