Numerical Simulation of Aerodynamics Performance of NERL S826 Airfoil

In this study, the aerodynamic coefficients of NERL S826 airfoil, used for small-scale wind turbines, are numerically computed. To account for high skewness at a high angle of attack, an unstructured mesh with two different turbulence models, namely The k- $\omega$ SSt and Spalert-Allmaras was implemented using the OpenFOAM-2206 tool. The simulation results are validated against wind tunnel experimental data obtained in the same flow conditions. Moreover, the results also are compared with other numerical simulations conducted for the same type of airfoil using an OpenFOAM-06 with a structured mesh. Additionally, blade element theory (BET) was considered in the comparison of the aerodynamic characteristics. It was found that the results for the drag coefficients achieved by OpenFOAM-2206 simulation for both turbulence models are in less agreement with the experiment in comparison with those obtained by OpenFOAM06, particularly for the AOA in the range of $0^{\circ}-12^{\circ}$. However, a better prediction of the drag coefficients was achieved for higher AOA by OpenFOAM-2206 simulation with the k- $\omega S S T$ model and unstructured mesh compared with the other methods. On the other hand, an excellent agreement between OpneFOAM-2206 results in the lift coefficients with the experiment was obtained in comparison with the other methods.