Disperze prachových částic v blízkosti uličního kaňonu silně zatíženého pozemní dopravou - počítačové modelování a porovnání s měřením

PM Dispersion Around a Heavily Trafficked Street Canyon and Neighbouring Streets - Computational Modeling and Comparison With Measurements

conference paper

en

In this paper authors compare different ways of PM dispersion modeling in urban areas. The study is focused on dispersion of particulate matter originating from traffic. CFD code StarCD has been used as appropriate tool that is capable of correct velocity field prediction at small-scale numerical models. Different options of CFD technique and different approaches were tested. The numerical predictions were compared with measurement carried out in a heavily built up urban area. The computational model represents part of the area in the center of the city of Brno. The solution domain involves an area of approximately 0.5 x 0.5 km and includes one long street canyon, Kotlarska street, together with four streets that cross the main street canyon. Boundary condition for wind speed assumes specified wind speed in the horizontal layer where it was measured. Sidewalls of the solution domain are prescribed with pressure boundary conditions. The top of the domain uses condition of a slip wall. As a model of turbulence, k-? The RNG model was used. To simulate traffic, an original model developed previously by the authors is used that takes into account traffic density, speed of cars and number of traffic lanes. PMs are assumed spherical with a density of 300 kg/m3. Only PM10 are modeled that also were measured in several locations within the street canyon and crossing streets, both at the ground level.

V tomto příspěvku autoři porovnávají dva přístupy modelování transportu prachových částic v městských oblastich. Studie je zaměřena na částice pocházející z dopravy. Jako vhodný modelivý prastředek byl využit StarCD, schpný korektního řešení rychlostních polí v modelech malých rozměrů. Testována bya různá nastavení a přiblížení jejichž výsledky byly porovnány s měřením provedeným uvnitř městské zástavby. Jako vhodná modelová oblast byla vybrána lokalita ve vnitřní části města Brna a půdorysným tvarem 0,5x0,5 km. Vítr byl zadán pomocí rychlostní hladiny nad střechami budov. Bočním stěnám numerického modelu byla přiřazena tlaková okrajová podmínka. Horní omezující plocha modelu byla popsána jako stěna bez tření. RNG model turbulence byl použit pro všechny realizované výpočty. Uvažovány byly částice kulového tvaru s hustotou 300 kg/m3. Modelovány byly částice PM10, jejichž hmotnostní koncentrace byly měřeny v přízemní vrstvě řešené oblasti.

In this paper authors compare different ways of PM dispersion modeling in urban areas. The study is focused on dispersion of particulate matter originating from traffic. CFD code StarCD has been used as appropriate tool that is capable of correct velocity field prediction at small-scale numerical models. Different options of CFD technique and different approaches were tested. The numerical predictions were compared with measurement carried out in a heavily built up urban area. The computational model represents part of the area in the center of the city of Brno. The solution domain involves an area of approximately 0.5 x 0.5 km and includes one long street canyon, Kotlarska street, together with four streets that cross the main street canyon. Boundary condition for wind speed assumes specified wind speed in the horizontal layer where it was measured. Sidewalls of the solution domain are prescribed with pressure boundary conditions. The top of the domain uses condition of a slip wall. As a model of turbulence, k-? The RNG model was used. To simulate traffic, an original model developed previously by the authors is used that takes into account traffic density, speed of cars and number of traffic lanes. PMs are assumed spherical with a density of 300 kg/m3. Only PM10 are modeled that also were measured in several locations within the street canyon and crossing streets, both at the ground level.

particulate matter, CFD modeling, dispersion

2005

01.01.2005

Verlag TU Graz

Garmisch-Partenkitchen

3-902465-16-6

14th Symposium Transport and Air Pollution

309–317

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