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Relation of puff and continuous dispersion within urban canopy
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SYSNO ASEP 0437112 Document Type C - Proceedings Paper (int. conf.) R&D Document Type The record was not marked in the RIV Title Relation of puff and continuous dispersion within urban canopy Author(s) Chaloupecká, Hana (UT-L) RID, ORCID, SAI
Jurčáková, Klára (UT-L) RID, ORCID
Jaňour, Zbyněk (UT-L) RID, ORCIDSource Title 16th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes. - Varna : National Institute if Meteorology and Hydrology, 2014 Pages s. 694-698 Number of pages 5 s. Publication form Print - P Action International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes /16./ Event date 08.09.2014-11.09.2014 VEvent location Varna Country BG - Bulgaria Language eng - English Country BG - Bulgaria Keywords atmospheric boundary layer ; pollution dispersion ; instantaneous release ; wind tunnel Subject RIV DG - Athmosphere Sciences, Meteorology R&D Projects LD12007 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) Institutional support UT-L - RVO:61388998 Annotation Protection of inhabitants of densely populated urban areas is a very important topic. Residents can be threatened by accidental releases of toxic gases. These releases can occur e.g. from a factory working with chemicals, a vessel transporting chemicals, or by an intentional attack. Most of such releases have duration of few minutes to one hour. This leads to dispersion pattern called puff. Due to stochastic nature of turbulence of the atmospheric flow the prediction of puff dispersion is possible only in statistical sense. The presented paper will introduce dispersion experiments of both puff and continuous releases within an urban canopy. The experiments were conducted at the environmental wind tunnel of the Institute of Themomechanics. The model of an idealised urban canopy representing typical European architecture consisting of rectangular blocks of buildings with pitched roofs and inner courtyards was manufactured in the scale 1:400. A point source of tracer gas was mounted at the ground level. Flow and dispersion was measured by time resolving instruments (Laser Doppler Anemometry and Flame Ionisation Detector, respectively). At each point concentration time series from continuous and puff (i.e. ensembles of puff realisations) releases were recorded. Characteristics of the puff case as well as the continuous case were calculated. Linear relationship between mean concentrations in the continuous case and mean 99%, as well as mean 95% quantile of concentrations in the puff case within separate traverse streets in view of flow is perceptible from the results. Assessment of puff ensemble characteristics by continuous dispersion characteristics is highly valuable, since many numerical models calculate only with Reynolds averaged equations and they are able to predict only statistics of continuous dispersion. Workplace Institute of Thermomechanics Contact Marie Kajprová, kajprova@it.cas.cz, Tel.: 266 053 154 ; Jana Lahovská, jaja@it.cas.cz, Tel.: 266 053 823 Year of Publishing 2015
Number of the records: 1