MRI Investigations of Internal Blade Cooling Flow and CFD Optimization Through Data Matching

Abstract

Abstract The optimal turbulence model to be used in a CFD simulation varies depending on the application and the scientific question at hand. It is always a difficult task to predict which model best represents reality. This study focuses on the internal cooling system of a high-pressure turbine airfoil. It presents a CFD validation routine, which includes a data matching process with experimental data as well as global and local error metrics to quantify the differences between the experiment and CFD. The experimental data of the time-averaged three-dimensional velocity field is obtained with Magnetic Resonance Velocimetry (MRV). The airfoil in question is a second stage blade of a small industrial gas turbine, consisting of a three-pass internal cooling serpentine. The three-dimensional three-component MRV data is compared to CFD using the data matching process and the error metrics. The simulations are performed with the eddy-viscosity based turbulence model k-ω SST and the Reynolds-Stress SSG, and BSL-EARSM turbulence models. The results indicate local differences between the examined turbulence models and the MRV results. Referring to the global and local error quantities presented in the study, the BSL turbulence model is identified as the optimal turbulence model for this specific high-pressure turbine airfoil.