Comparison study of turbine blade with trailing-edge cutback coolant ejection designs

This paper investigates a turbine blade with two trailing-edge cutback coolant ejection designs, aiming for a comparison study of aerothermal performances such as discharge coefficient and film cooling effectiveness due to trailing-edge geometry change. Steady Reynolds-averaged Navier-Stokes (RANS) and two-equation turbulence models are adopted and numerical studies are carried out by two-stage investigations:- firstly, validation of an existing cutback blade model (i.e., half a blade model with pressure-side geometry only) that has been extensively studied experimentally and numerically by other researchers and predicted internal passage discharge coefficient and film cooling effectiveness along cutback surface are compared to experimental measurements; secondly, exploration of a more realistic blade model with full trailing-edge cutback geometry to understand possible performance changes due to new model design. It was found that steady RANS modelling are able to produce discharge coefficients and wall pressure distributions in fairly good agreement with test data, but not the film cooling effectiveness on cutback surfaces which under-predicts in near-field wake region, and over-predicts in far-field wake region. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.