Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Force and torque acting on particles in a transitionally rough open channel flow
Wind-tunnel studies of dispersion processes of traffic exhaust in urban street canyons with tree planting were performed and tracer gas concentrations using electron capture detection (ECD) and flow fields using laser Doppler velocimetry (LDV) were measured. It was found that tree planting reduce the air exchange between street canyons and the ambience. In comparison to treeless street canyons, higher overall pollutant concentrations and lower flow velocities were measured. In particular, for perpendicular approaching wind, markedly higher concentrations at the leeward canyon wall and slightly lower concentrations at the windward canyon wall were observed. Furthermore, a new approach is suggested to model porous vegetative structures such as tree crowns for small-scale wind-tunnel applications. The approach is based on creating different model tree crown porosities by incorporating a certain amount of wadding material into a specified volume. A significant influence of the crown porosity on pollutant concentrations was found for high degrees of porosity, however, when it falls below a certain threshold, no further changes in pollutant concentrations were observed.
Force and torque acting on particles in a transitionally rough open channel flow
Wind-tunnel studies of dispersion processes of traffic exhaust in urban street canyons with tree planting were performed and tracer gas concentrations using electron capture detection (ECD) and flow fields using laser Doppler velocimetry (LDV) were measured. It was found that tree planting reduce the air exchange between street canyons and the ambience. In comparison to treeless street canyons, higher overall pollutant concentrations and lower flow velocities were measured. In particular, for perpendicular approaching wind, markedly higher concentrations at the leeward canyon wall and slightly lower concentrations at the windward canyon wall were observed. Furthermore, a new approach is suggested to model porous vegetative structures such as tree crowns for small-scale wind-tunnel applications. The approach is based on creating different model tree crown porosities by incorporating a certain amount of wadding material into a specified volume. A significant influence of the crown porosity on pollutant concentrations was found for high degrees of porosity, however, when it falls below a certain threshold, no further changes in pollutant concentrations were observed.
Force and torque acting on particles in a transitionally rough open channel flow
Chan-Braun, C. (Autor:in) / García-Villalba, M. (Autor:in) / Uhlmann, M. (Autor:in)
15.01.2013
Journal of Fluid Mechanics, 684, 441-474 ; ISSN: 0022-1120
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
DDC:
690
Turbulence characteristics in an open channel flow over transitionally rough bed
| Taylor & Francis Verlag | 2014
ROLLING MOTION OF PARTICLES OVER TRANSITIONALLY-ROUGH BED
| Taylor & Francis Verlag | 2011
Near-bed particle motion over transitionally-rough bed
| British Library Online Contents | 2011
Near-bed particle motion over transitionally-rough bed
| Taylor & Francis Verlag | 2011
Spatially Averaged Open-Channel Flow over Rough Bed
| British Library Online Contents | 2001