Abstract
Since the wind-power energy is proportional to wind velocity cubed, it is crucial to predict a correct profile of wind in selecting the best site for a wind-power plant. The effects of the ground are often neglected owing to the very large length scale of the real environment. However, the complex terrain affects a profile of wind near the ground. Therefore, we have to consider the ground effects to obtain an exact profile of wind near the ground. In this study, to evaluate the performance of a low-Reynolds-number type turbulence model in an atmospheric boundary layer, we calculated a stable boundary layer flow with a roughness surface. Also, we proposed a turbulence model including the effects of the roughness and the buoyancy. Moreover, to assess the prediction of the turbulence model on a complex terrain, we carried out a simulation of a forward-facing step flow. In this case, it is well known that the turbulence energy is overpredicted by the k-ε model at the stagnation point; thus, we have improved the model introducing the time scale based on the velocity gradient parameter. The proposed model indicates good agreement with the experimental data.
