Prediction of particle erosion in the internal cooling channels of a turbine blade

Authors

D. Anielli - Dept. of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
D. Borello - Dept. of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
F. Rispoli - Dept. of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
A. Salvagni - Dept. of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
P. Venturini - Dept. of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy

Abstract

A multi-phase computational approach was adopted for predicting particle erosion in a domain that is representative of the trailing edge region of a rotor blade. The flow field was solved by an in-house FV code adopting a non-linear k-eps-zeta-f elliptic relaxation RANS turbulence model. The model demonstrated to be able to reproduce the anisotropy of near-wall turbulence and, partly, the influence of streamlines curvature on the turbulent flows. Furthermore, URANS predicted very strong unsteadiness that allowed to reconstruct part of the turbulence spectrum and to identify the relevant frequencies. A Lagrangian particle tracking model was used for predicting particle dispersion and erosion of the solid surfaces. Impact mechanisms was modelled using the Tabakoff model, previously validated by the authors on a number of studies. Two particles classes were investigated (5 and 20 μm). The trajectories of the smallest particles were prone to follow the streamlines pattern and erosion rates are also influenced by impact angle. As for the greater particles, the erosion mechanism is mainly dependent from inertia forces.