Atmospheric boundary layer over urban roughness: Insights from mean-flow statistics
A wall-modeled large-eddy simulation database of an atmospheric flow over urban configurations (Teng et al. Phys. Fluids 37, 065129, 2025), obtained using a high-fidelity spectral-element method, is analyzed. The database comprises two urban geometries: (i) an in-line array of cubic prisms and (ii)...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:upcommonspor::1f9682d52922c518edcdb240b98dcd3a |
| Acceso en línea: | https://hdl.handle.net/2117/460897 https://dx.doi.org/10.1016/j.ijheatfluidflow.2026.110406 |
| Access Level: | acceso abierto |
| Palabra clave: | Atmospheric boundary layer Urban roughness Wall-modeled large-eddy simulation (WMLES) Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids |
| Sumario: | A wall-modeled large-eddy simulation database of an atmospheric flow over urban configurations (Teng et al. Phys. Fluids 37, 065129, 2025), obtained using a high-fidelity spectral-element method, is analyzed. The database comprises two urban geometries: (i) an in-line array of cubic prisms and (ii) a heterogeneous Michelstadt model, with plan area densities of = 0.25 and 0.31, and frontal area densities of = 0.25 and 0.24, respectively. In both cases, the incident wind angle is 0◦. The corresponding Reynolds numbers based on the mean building heights are = 5.0 × 106 and 6.0 × 106, respectively ( denotes the mean building height). The present study addresses the mean-flow behavior of the atmospheric boundary layer over these two urban configurations, with particular emphasis on the effects of urban configuration within the roughness sublayer. In addition to conventional mean statistics, turbulence anisotropy is characterized through the anisotropy invariant function and the Lumley triangle. The results reveal that heterogeneity in the Michelstadt configuration generates a more complex and spatially varying flow field, in contrast to the periodicity of the cube array. The thickness of the roughness sublayer in Michelstadt case is substantially higher than that in the array of cubic prisms. In both cases, the spatial distribution of the anisotropy invariant function exhibits an inverse relationship with the turbulent kinetic energy, attributed to the dominance of the streamwise Reynolds stress. These findings provide deeper insights into roughness-induced flow patterns and reference data for parameterizations within urban canopy. |
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