Investigation of the Performance of Turbulence Models With Respect to High Flow Curvature in Centrifugal Compressors

Abstract

The goal of this research is to evaluate the performance of three turbulence models with respect to flow with high curvature in a centrifugal compressor stage designed for an aero-engine. The effectiveness of the curvature correction terms in the two-equation turbulence models is the main focus of this study, as implemented in the curvature-corrected shear stress transport (SST-CC) model of Smirnov and Menter. The SST-CC model uses a production multiplier in the k and ω equations. SST-CC results were compared against the SST model and previous simulations by Bourgeois et al. (2011, “Assessment of Turbulence Model Predictions for an Aero-Engine Centrifugal Compressor,” ASME J. Turbomach., 133(1), pp. 1–15) using the Reynolds stress model (RSM–SSG) for stage performance characteristics, experimental velocity profiles at the impeller–diffuser interface, and velocity contours at the diffuser exit. The production multiplier was investigated in the compressor impeller. The comparisons showed that the SST-CC model better predicted the choke region in the pressure characteristic and efficiency characteristic, whereas the SST model better predicted the stall region. However, both models predicted a similar mean flow velocity field. Analysis of the production multiplier demonstrated that the term provided the expected effects near the walls of the convex and concave surfaces. However, away from the walls where turbulent production term was insignificant, the production multiplier showed abnormal predictions. The rotation effects were found to be weaker than the curvature effects near the impeller trailing edge of the current compressor.