Estimation of scalar fluxes within modelled intersection depending on the approach flow direction

0346081 - ÚT 2011 RIV FR eng C - Conference Paper (international conference)
Kukačka, Libor - Kellnerová, Radka - Jurčáková, Klára - Jaňour, Zbyněk
Estimation of scalar fluxes within modelled intersection depending on the approach flow direction.
Proceedings of the 13th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes. Boulogne-Billancourt: ARIA Technologies, 2010, s. 797-801. ISBN 2-8681-5062-4.
[International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes. Paris (FR), 01.06.2010-04.06.2010]
Institutional research plan: CEZ:AV0Z20760514
Keywords : air pollution * atmospheric boundary layer * physical modelling * contaminant spreading
Subject RIV: DG - Athmosphere Sciences, Meteorology
www.harmo.org

In built-up areas street intersections represent regions of dangerous pollutant exchanges between street-canyons. The objective of this study is to investigate the influence of the approach flow direction on contaminant spreading within an intersection in an idealised symmetrical urban area. Mean velocity and concentration fields are measured at an urban area model in wind tunnel for five wind directions. Horizontal and vertical advective scalar fluxes are computed from measured data to quantify pollutant spreading. Experiment results show a significant sensitivity of measured quantities within the area on the approach flow direction. The highest contaminant concentrations and fluxes are measured in the bottom parts of street-canyons. The important role of the vertical turbulent scalar flux in street-canyon ventilation is expected because of non-zero sum of measured advective fluxes in the closed area. The set-up with the most favourable dispersion conditions in the studied area was found.
Permanent Link: http://hdl.handle.net/11104/0187195