並列摘要
In microclimate, most surface layer analyses assume uniform terrain conditions and a horizontally-homogeneous flow. However, a homogeneous environmental system rarely exists in the nature. A finite volume method with more reasonable physical meanings is introduced to consider a flow field over a changed roughness surface. In order to know how various types of surface affect the atmospheric turbulence structure, RSM (Reynolds Stress Model) is used. Surface roughness has a profound effect on wind speed. The rougher a terrain is, the more it retards the wind in the atmospheric boundary layer. This study reveals that the variation of turbulent boundary layer due to rough-to-smooth is less than that in the smooth-to-rough. The distribution of the turbulence intensities also depicts the variations of the internal boundary layer. The higher height a terrain surface has, the more variation it exhibit near the step change.