20.500.12556/RUL-173414 Vpliv izbire RANS turbulentnega modela na učinkovitost izračuna zastojnega kota aerodinamičnega krila Formule Student The impact of the choice of RANS turbulent model on the efficiency of stall angle calculation V zaključnem delu smo napovedali zastojni kot aerodinamičnega krila na podlagi računalniške dinamike tekočin s programom Ansys Fluent. Uporabili smo turbulentne modele Spalart-Allmaras (SA), k-$\epsilon$ in k-$\omega$ za zaprtje Reynoldsovo povprečenih Navier-Stokesovih enačb. Analiza je bila narejena na krilu NACA4412 širine 0,25 m in dolžine 0,15 m s končno ploščo višine 0,11 m pri toku zraka z Re = 207 000. Izdelana je bila analiza občutljivosti velikosti računske domene ter analiza gostote mreže. Ugotovili smo, da je za neodvisnost rezultatov potrebujemo domeno, ki je oddaljena 15 dolžin krila povsod, razen za krilom, kjer je potrebnih 45 dolžin. Največja velikost mreže, zadostna na podtlačni površini krila, je 1,5 mm, na nadtlačni pa 2 mm. Primerjali smo dobljene rezultate tlačnega in hitrostnega polja na površini krila ter različnih prerezih ter iz koeficientov aerodinamičnih sil določili zastojni kot. Analiza je pokazala, da modeli SA, k-$\epsilon$ in k-$\omega$ predvidijo zastojne kote 23, 21 in 21 $^°$C. Računsko je bil najhitrejši k-?, najpočasnejši pa k-$\omega$ model. Zaradi področja uporabe in validacije je model k-$\omega$ izmed analiziranih najbolj primeren za uporabo v Formuli Student. 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. aerodinamika računalniška dinamika tekočin RANS turbulentni modeli Formula Student aerodinamično krilo zastojni kot separacija toka ob krilu aerodynamics computational fluid dynamics RANS turbulence models Formula Student aerodynamic wing stall angle separation of flow around a wing true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-09-17 08:30:25 2025-09-17 08:30:29 2025-11-08 04:07:33 0000-00-00 00:00:00 2025 0 0 XIV, 65 f. 2025 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 533.6:532.517.4:004.94(043.2) 276518 249318147 44567.pdf 44567.pdf 1 EF5CEF171F0B0A4773AA620D40608453 2b34e3d1df4135cc0228de3b7739d298a0d4531eab062f671cc00b3d180fb617 a1ade86a-938f-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=217824 Fakulteta za strojništvo 0 0 0