Experimental Validation of NACA 6321 Airfoil Characteristics Obtained Using Different Turbulence Models

Abstract

Abstract: Numerical analysis of NACA 6321 aerofoil is conducted at different angles of attack with constant velocity using three turbulence models and the results are validated with experimental findings. The simulation study is conducted by solving the steady-state governing equation of continuity and momentum using the Spalart-Allmaras, k-omega, and k-epsilon models; the obtained results are compared with experimental data. Aerodynamic parameters are calculated and then juxtaposed with experimental data acquired from experiments performed in a subsonic tunnel. The study reveals that the results generated by the k-omega model exhibit a strong correlation with the experimental findings at low and high angles of attack when compared to other turbulence models. In contrast to the k-epsilon and the Spalart-Allmaras models, the prediction of the stalling angle of attack has an error of  20% in comparison to the experimental evaluation. The results of the k-omega turbulence model predict the turbulence properties pretty well in the NACA 6321 aerofoil with an error of less than 4%. Keywords: NACA 6321, Spalart-Allmaras, k-omega and k-epsilon, Turbulence models.