New Evaluation Technique for WTG Design Wind Speed Using a CFD‐Model‐Based Unsteady Flow Simulation with Wind Direction Changes

Because a significant portion of the topography in Japan is characterized by steep, complex terrain, which results in a complex spatial distribution of wind speed, great care is necessary for selecting a site for the construction of wind turbine generators (WTG). We have developed a CFD model for unsteady flow called RIAM‐COMPACT (Research Institute for Applied Mechanics, Kyushu University, computational prediction of airflow over complex terrain). The RIAM‐COMPACT CFD model is based on large eddy simulation (LES). The computational domain of RIAM‐COMPACT can extend from several meters to several kilometers, and RIAM‐COMPACT can predict airflow and gas diffusion over complex terrain with high accuracy. The present paper proposes a technique for evaluating the deployment location of a WTG. The proposed technique employs the RIAM‐COMPACT CFD model and simulates a continuous wind direction change over 360 degrees.