Turbulence model comparisons for a low pressure 1.5 stage test turbine

Abstract

In a gas turbine engine secondary flows have a detrimental effect on efficiency. The current numerical study is aimed at determining which turbulence model in a commercially available CFD code is best suited to predicting the secondary flows. Experimental validation is used to determine the appropriateness of the model. The numerical study was performed using Numeca’s FINETM/Turbo and all of the appropriate turbulence models were tested. It was found that the Baldwin- Lomax, Spalart-Allmaras and k-e predicted the magnitude of the velocity well, but did not capture the velocity magnitude profile well. The k-w and the SST k-w captured the profile better, but did not predict the average value as well as the other models tested. It is for this reason that the SST k-w turbulence model was chosen as the most suitable for analysis of secondary flows, as the flow features are more accurately predicted, thus aiding in understanding secondary flow.