In this paper, the results of aerodynamic and aeroacoustic calculation of a MW-class horizontal axes wind turbine (HAWT) are presented. Improved Delayed Detached Eddy Simulation (IDDES), as a hybrid LES-RANS turbulence model, is applied to simulate instantaneous flow field around the HAWT. The noise attenuation in the far field is estimated with the Ffowcs Williams and Hawking's acoustic analogy. Improved Blade Element Momentum (IBEM) theory and Brooks, Pope and Marcolini (BPM) semi-empirical methods also are implemented for wind turbine output power and aeroacoustic noise calculation. The semi-empirical and CFD methods are validated against experimental data of AOC 50/15 HAWT. The results show good agreement with experimental data for both IBEMBPM and CFD techniques. The contribution of the thickness, loading, and quadrupole sources in far field noise propagation are investigated. Then, those methods are implemented for aerodynamic and aeroacoustic prediction of the NREL's 1.5 MW WP_Baseline HAWT. The Results obtained by CFD and IBEM-BPM techniques are compatible with each other for the 1.5 MW HAWT.
