In the thesis, we predicted the stall angle of an aerodynamic wing using computational fluid dynamics with the Ansys Fluent code. Turbulence models Spalart-Allmaras (SA), k-$\epsilon$, k-$\omega$ were used to close the Reynolds-averaged Navier-Stokes equations. Analysis was conducted on the NACA4412 wing, which had a width of 0.25 m, a length of 0.15 m, and vertical endplates of a height of 0.11 m, at an air flow with Re = 207 000. A numerical domain size analysis and mesh size study were performed. It was found that, for independence of the result, the domain walls must exceed 15 lengths of wing everywhere, except for rearwards of the wing, where 45 lengths are required. The mesh size on the dorsal surface of the wing must be 1,5 mm, while on the ventral surface, 2 mm refinement is required. We compared the results of the pressure and velocity fields on the wing surface and different cross-sections and determined the stall angle from the coefficients of aerodynamic forces. The analysis showed that the SA, k-\epsilon and k-$\omega$ models predict stall angles of 23, 21 and 21 $^°$C. The k-\epsilon model was computationally the fastest, and the k-$\omega$ model the slowest. Due to the scope of application and validation, the k-$\omega$ model is the most suitable for use in the Formula Student among the analysed ones.
|
