Avalição de resultados de simulação numérica de escoamento sobre o perfil NACA 2410 utilizando o OpenFOAM com diferentes modelos de turbulência

Abstract

This work presents a computational analysis of the flow over a NACA 2410 aerodynamic profile, aiming to verify the behavior of the drag and lift coefficients for different angles of attack, applying three different turbulence models, (k-epsilon, k-omega SST and Spalart-Allmaras). The software used was the OpenFOAM, which is a Computational Fluid Dynamics open source package, with the capacities of mesh generation, solution obtaining and post processing. The following parameters were used to generate the meshes: ten times the chord length upstream, fifty times the chord length downstream, fifteen layers over the profile and two cycles of the refining box. These parameters have already shown to be satisfactory to the numerical solution in former works. The lift and drag coefficients obtained for different angles of attack were compared against experimental data found in literature. The lift coefficient values were in general underestimated, ranging from three percent to small angles of attack until thirty four percent to high angles of attack, indicating the difficulty that the turbulence models have to preview the boundary layer separation point. The biggest discrepancies occurred in the drag coefficient values, which presented variations in the order of one thousand percent. Above all this fact was already previewed, since the models assume that the flow is turbulent over all the profile, what is not true, because there is a significant extension where the regime is laminar. It can be seen that the aerodynamic performance evaluation must be taken with care, keeping in mind the advantages and limitations of the applied tools.