建物群内外における流れ場の乱流特性と組織運動

抄録

This review considers observational and experimental knowledge of turbulence characteristics and organized motions in and above building clusters, drawing from both atmospheric and laboratory data. The former describe the structure of the roughness sublayer in which the roughness has a direct dynamical influence, whereas the latter resolve the flow structure within building clusters in some detail, Topics considered include the turbulent velocity fields and organized motions above the cluster layer, properties of the wake flow within bulding clusters, and the nature of the separation bubble on the building roof. Overall, there are three types of turbulent flows which play important roles in the transport of heat and pollutants in and above building clusters: the organized motions transport heat near the cluster layer and decrease unstable conditions in the urban area, the turbulent wake flows determine the maximum values of concentration at ground-level, and the separations on the building roof control transport and dispersion of tracer gas emitted from the rooftop.