Maio 2014 vol. 1 num. 1 - 10th World Congress on Computational Mechanics
Full Article - Open Access.
FINITE ELEMENT SIMULATION OF NON-ISOTHERMAL POLLUTANT DISPERSION IN URBAN STREET CANYONS USING SHARED MEMORY PARALLELIZATION
A finite element model to simulate pollutant dispersion and thermal effects over the flow field of urban street canyons is presented in this work. Street canyons constitute the basic geometric unit in urban areas, where a narrow passage surrounded by buildings is usually formed. In the street canyons, micro-scale meteorological processes dominate, which are mainly characterized by solar radiation effects and wind-induced flow patterns. Owing to the large amount of pollution emitted from engines of motor vehicles and geometrical configurations of the street canyons, air quality is considerably deteriorated in large cities, having an important impact on human health. In order to evaluate the pollutant dispersion in those areas, field measurements, wind tunnel techniques and numerical simulation have been usually adopted. However, only numerical simulation can efficiently provide results with high spatial/ temporal resolution and comprehensive information on the flow field and the pollutant transport. Therefore, a numerical model based on CFD techniques is proposed in this work to simulate incompressible flows considering heat and mass transfer phenomena. In the present model, an explicit two-step Taylor-Galerkin scheme is adopted where the spatial discretization is performed using the finite element method (FEM) with eight-node hexahedral elements, one-point quadrature and hourglass control techniques. The pressure field is explicitly obtained by using the pseudo-compressibility hypothesis and the velocity and temperature fields are coupled by buoyancy forces according to the Boussinesq approximation. Large eddy simulation (LES) is utilized to analyze turbulent flows, where the sub-grid scales are modeled using both, the classical Smagorinsky’s model and the dynamic model. Programming techniques for shared memory parallelization are also utilized in order to improve the performance of the present numerical code. Applications reproducing street-canyon configurations are numerically analyzed using a parametric study based on the main parameters utilized to define the flow characteristics.
Palavras-chave: Computational Fluid Dynamics (CFD), Finite Element Method (FEM), Pollutant Dispersion, Non-Isothermal Flow, Large Eddy Simulation (LES).,
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Madalozzo, D.M.S.; Braun, A.L.; Awruch, A.M.; "FINITE ELEMENT SIMULATION OF NON-ISOTHERMAL POLLUTANT DISPERSION IN URBAN STREET CANYONS USING SHARED MEMORY PARALLELIZATION", p. 1671-1691 . In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1].
São Paulo: Blucher,
ISSN 2358-0828, DOI 10.5151/meceng-wccm2012-18509
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