Wind tunnel experiments were performed to examine the effect of a tall tower on the flow around an otherwise uniform array of buildings. Additionally, preliminary CFD simulations were run to visualize the flow with more resolution. The model used in both the wind tunnel and CFD studies was designed to simulate an area of Brooklyn, NY, USA, where blocks of residential row houses form a neighborh...

In this study we investigate ultrafine particle (UFP) fluxes using a first order eddy viscosity turbulence closure Computational Fluid Dynamics (CFD) model and determine the different factors that influence emissions of UFP into the urban boundary layer. Both vertical turbulent fluxes as well as the fluxes due to mean circulatory flow are shown to contribute to the overall ventilation character...

High concentrations of ozone (O3) is a major air problem in urban areas, which creates serious threat to human health. Urban street canyon morphology plays key role pollutant dispersion and photochemical reaction rate. In this study, one-year observation at three height levels was performed investigate the O3 distribution vertically Shenyang. Then, field investigation ENVI-met modelling were co...

Greening cities is a key solution to improve the urban microclimate and mitigate impact of climate change. However, effect tree planting on pollutant dispersion in streets still debated topic. To shed light this issue, we present wind-tunnel experiment aimed at investigating trees street canyon ventilation. An idealized district was simulated by an array blocks, two rows model were arranged sid...

Combustion of fossil fuel in gasoline and diesel powered vehicles is a major source of aerosol particles in a city. In a street canyon, the number concentration of particles smaller than 300 nm in diameter, which can be inhaled and cause serious health effects, is dominated by particles originating from this source. In this study we measured both, particle number size distribution and traffic d...

Traffic–related pollutant has been recognized as an air pollution hot spot due to its large emission rate and great health impacts for the exposed population. In the present investigation, a computational fluid dynamics technique is used to evaluate the effect of traffic pollutions on indoor air quality of a naturally ventilated building. The transport of street-level nonreactive pollutants emi...

This study assesses the sensitivity of numerical results of air flow modelling within an urban environment to the six different turbulence models applied in a specific case of a studied staggered cross-road. The principal parameters investigated in this comparison are position of centres of vortices within a street canyon, two components of the spatial velocity vector, turbulent kinetic energy,...

Urbanization, the expansion of built-up areas, is an important yet less-studied aspect of land use/land cover change in climate science. To date, most global climate models used to evaluate effects of land use/land cover change on climate do not include an urban parameterization. Here, the authors describe the formulation and evaluation of a parameterization of urban areas that is incorporated ...

The Global Positioning System (GPS) has been widely used in land vehicle navigation applications. However, the positioning systems based on GPS alone face great problems in the so called urban canyon environments where the GPS signals are often blocked by high buildings and there are not enough available satellites signals to estimate the positioning information of a x. To solve the problem, a ...

http://www.revistadechimie.ro 61 Road traffic is one of the main sources of atmospheric pollution in urban areas, where the contribution of traffic flows, congestions and high population density typically increases the exposure of the settled population to pollutants [1-3]. One of the most important family of traffic-related pollutants is represented by nitrogen oxides (NOx), whose main contrib...