Calculations of flow around airfoils using two-dimensional RANS: an analysis of the reduction in accuracy

Flows around sets of airfoils with different shapes and thicknesses have been numerically investigated at relatively high Reynolds numbers (Re ≥ 106) and low turbulence intensity (I ≤ 0.1%) using two-dimensional (2D) Reynolds-Averaged Navier-Stokes equations (RANS) closed by different turbulence models. The effects of a set of factors such as wind tunnel walls, the compressibility and the influence of the laminar-turbulent transition were investigated. The most likely reasons for the systematic disagreement between simulation and experimental data were established to be 3D effects ignored by 2D simulation, and imperfection of the existing turbulence models.