Layer Character of Wind Fields over the Simplified Gorge Terrain

Abstract

Characteristics of wind fields over gorge terrains are important not only for pollution dispersion and forest fires but also for civil structures. However, current studies are aimed only at specific gorge terrains. Thus, limited references are available for other engineering practices. Four V-shaped simplified gorge terrains were modeled in the computational domain to investigate the fundamental information of wind fields over gorge terrains, especially the layer character of the wind fields over gorge terrains. The values of mean wind speed and turbulence intensity were analyzed based on the numerical simulations on the wind fields over the four simplified gorges, and the method to calculate the height of the gorge inner layer was proposed. Results show that the wind fields over the simplified gorge terrains can be divided into two layers in the vertical direction, that is, the gorge inner layer and gorge outer layer. This finding proves that the layer character of wind fields exists in gorge terrains. The heights of the gorge inner layer are 0.242 m, 0.224 m, 0.215 m, and 0.208 m, respectively, which correspond to the gorge terrains with included angles of 80°, 100°, 120°, and 140°. This result implies that the smaller the included angle of the gorge terrain is, the higher the gorge inner layer becomes. The proposed method to calculate the height of the gorge inner layer was proved to be accurate, indicating that the derivation process is reasonable and reliable. The study provides new insights on investigating the characteristics of wind fields over gorge terrains.