Computational fluid dynamics (CFD) analysis is carried out to evaluate the compressible aerodynamics of a large horizontal axis wind turbine blade. The mean turbulent flow around the rotating blade is simulated by adopting the unsteady Reynolds-averaged Navier-Stokes modelling approach, where the governing equations are solved by means of a finite volume-based numerical method, supplied with a two-equation eddy-viscosity turbulence model. The present CFD model using an open-source code for computational wind engineering applications was verified to have significant practical potential by making a comparison with a reference steady solution.