NUMERICAL SIMULATION OF A PAK-B AIRFOIL USING FULLY TURBULENT AND TRANSITION-SENSITIVE RANS MODELS

Numerical simulations of a PAK-B airfoil cascade have been performed using commercially available fully turbulent and transition-sensitive RANS models. A range of Reynolds numbers (25000 to 300000) and free-stream turbulence intensities (0.5 % and 9%) were considered. Test conditions matched experiments by Volino (2002), and results from both turbulent and transition-sensitive RANS models are compared with the available experimental data. Two-equation fully turbulent RANS models failed to accurately predict the separation and reattachment region on the suction side of the airfoil. At Reynolds number 100000 and higher, in contrast to the experimental results, the SST model failed to predict flow separation even for low free-stream turbulence intensity cases. The transition sensitized RANS models; for instance transition-sensitive SST, and k-kL-ω models were able to predict separation and reattachment in most of the test cases. The k-kL-ω model produced reasonable results for low free-stream turbulence intensity cases, while the transition sensitized SST model results were close to experimental results for high free-stream turbulence intensity cases. Predicted location of the separation point was almost independent of Reynolds number for both transition models