Investigation of a Dynamic Hybrid Turbulence Modeling Strategy for CFD Simulation of Compound-Angle Film Cooling

Abstract Consistently accurate computational prediction of the complex flow physics associated with gas turbine hot section component film cooling is important for ensuring effective and efficient heat transfer design. Since these flow fields are naturally highly turbulent and anisotropic, accurate yet cost-effective turbulence modeling techniques are a critical aspect of computational fluid dynamics (CFD) based analysis. A previous study conducted by the authors investigated the capabilities of the dynamic hybrid RANS-LES (DHRL) turbulence modeling framework compared to an industry standard RANS k-ω SST model for a normal jet-in-crossflow [1]. In the present study, attention is focused on both fluid dynamics and adiabatic effectiveness for an engine representative film-cooling configuration with available high quality experimental results [2]. The geometry consists of a row of streamwise and compound angled round coolant film holes. The density ratio between the coolant and crossflow is 1.5, obtained via foreign gas injection, with the crossflow air at 305 K and a pure nitrogen coolant stream at 203 K. Two different coolant injection modes are investigated for all blowing ratios, including internal channel flow injection with counter channel flow direction, as well as plenum fed injection. The DHRL results are compared to industry standard RANS k-ω SST model results and to the experimental data, in terms of spatially and laterally averaged adiabatic effectiveness, to quantify the adiabatic effectiveness prediction accuracy of each modeling methodology.