Ventilation Processes in a Three-Dimensional Street Canyon

0458864 - ÚT 2017 RIV NL eng J - Journal Article
Nosek, Štěpán - Kukačka, L. - Kellnerová, Radka - Jurčáková, Klára - Jaňour, Zbyněk
Ventilation Processes in a Three-Dimensional Street Canyon.
Boundary Layer Meteorology. Roč. 159, č. 2 (2016), s. 259-284. ISSN 0006-8314. E-ISSN 1573-1472
R&D Projects: GA ČR GAP101/12/1554; GA ČR GA15-18964S
Institutional support: RVO:61388998
Keywords : Coherent structures * line source * pollution flux measurements * street canyon * wind tunnel
Subject RIV: BK - Fluid Dynamics
Impact factor: 2.573, year: 2016

The ventilation processes in three different street canyons of variable roof geometry were investigated in a wind tunnel using a ground-level line source. A constant roof height was used in the first case, while a variable roof height along the leeward or windward walls was simulated in the two other cases. All street-canyon models were exposed to a neutrally stratified flow with two approaching wind directions, perpendicular and oblique. The relative pollutant removals and spatially-averaged concentrations within the canyons revealed that the model with constant roof height has higher re-emissions than models with variable roof heights. The nomenclature for the ventilation processes according to quadrant analysis of the pollutant flux was introduced. The venting of polluted air increased when the wind direction changed from perpendicular to oblique, irrespective of the studied canyon model. Strong correlations (>0.5) between coherent structures and ventilation processes were found at roof level, irrespective of the canyon model and wind direction.
Permanent Link: http://hdl.handle.net/11104/0261311