This paper presents the results of three-dimensional and time-accurate, parallel Computational Fluid Dynamics (CFD) simulations of the flow field around a Horizontal Axis Wind Turbine (HAWT) rotor. Large Eddy Simulation (LES) methodology with an instantaneous loglaw wall model is used for the viscous computations. The 3-D, unsteady, parallel, finite volume flow solver, PUMA2, is used for the simulations. The solutions are obtained using unstructured moving grids rotating with the turbine blades. Three different flow cases with different wind speeds and wind yaw angles are investigated. Results for these three cases and comparisons with the experimental data are presented.