In this paper, the influence of turbulence modeling, Reynolds number and stall condition on the fluid numerical solution over NACA0012 airfoil is studied by using the OpenFOAM package. Large-eddy simulation (LES) turbulence model is used to simulate flow at a high angle of attack in near-stall or stall condition. Some vortexes are formed and caused to appear a fluctuation behavior of pressure distribution on the upper surface of the airfoil. Three RANS turbulence models, i.e., K- SST, K-ε and RNG K-ε are used at low angles of attack than stall condition and lift/drag coefficients of them are compared. Among different turbulence models, the best result for lift coefficient is obtained once K-w SST turbulence model is used and the best drag coefficient is obtained by RNG K-ε turbulence model. K-  SST turbulence model predicted the beginning of stall condition accurately whereas two other models were not able to predict it. The effects of Reynolds number on the lift coefficient have been investigated. It is observed that by increasing Reynolds number at constant Mach number the lift coefficient is increased and stall phenomena is happened at a higher angle of attack.

Keywords