Numerical simulation of wind flow over hilly terrain

Wind flow over hilly terrain is simulated by solutions of the Reynolds-averaged Navier–Stokes equations without the hydrostatic approximation. The standard and RNG-based k–ε models are used together with wall functions to account for surface roughness. The numerical model uses finite-volume discretization and boundary-fitted coordinates to resolve the terrain. Simulations were made for flow at four sites, namely, Cooperʹs Ridge, Kettles Hill, Askervein Hill and Sirhowy Valley, for which field data are available. Comparisons with wind data show agreement with respect to the profiles of local wind magnitude and direction. The numerical model is therefore deemed suitable for reliable prediction of local-scale wind flow over hilly terrain with regions of flow separation.