Abstract

The ability of computational fluid dynamic (CFD) to predict critical flow characteristics has always been questionable. Flow separation over lifting surfaces such as airfoils are one of the critical features which can significantly deteriorate their aerodynamic performances. The purpose of this research is to evaluate the accuracy of two CFD methods in predicting the flow separation over a NACA0025 airfoil at low Reynolds numbers. The first code is an in-house code which is based on a 3D compressible Navier-Stokes solver with preconditioning and self-adaptive upwinding methods. The second code is the commercial FLUENT software. In order to accurately simulate the laminar boundary layer separation, the Large Eddy Simulation (LES) method is used for turbulence modeling of both codes. Results comparison shows that Fluent is not able to capture this feature. In addition the results are also compared with another similar numerical simulation and validated with available experimental data.