The forces applied on a wing depend partly on its angle of attack. The goal of this report was to analyze the drag and lift coefficients of a NACA 2412 airfoil for various angles of attack. To get a diversity of results, three methods were used : experimental with a wind tunnel, theoretical with XFOIL code and numerical with ANSYS Fluent, where various models of the RANS turbulence-viscosity models are used and compared. The results obtained by each methods are compared, with the aim to understand the reasons behind the differences. An improvement proposition concludes this report.