Full Article - Open Access.

Idioma principal

FINITE ELEMENT SIMULATION OF NON-ISOTHERMAL POLLUTANT DISPERSION IN URBAN STREET CANYONS USING SHARED MEMORY PARALLELIZATION

Madalozzo, D.M.S.; Braun, A.L.; Awruch, A.M.;

Full Article:

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.

Full Article:

Palavras-chave: Computational Fluid Dynamics (CFD), Finite Element Method (FEM), Pollutant Dispersion, Non-Isothermal Flow, Large Eddy Simulation (LES).,

Palavras-chave:

DOI: 10.5151/meceng-wccm2012-18509

Referências bibliográficas
  • [1] Assimakopoulos, V. D, AP Simon, H. M., Moussiopoulos, N., 2003. A numerical study of atmospheric pollutant dispersion in different two-dimensional street canyon configurations. Atmospheric Environment, vol. 37, pp. 4037-4049.
  • [2] Baik, J.-J., Kim, J.-J., Fernando, H.J.S., 2003. A CFD model for simulating urban flow and dispersion. Journal of Applied Meteorology, vol. 42, pp. 1636-1648.
  • [3] Belytschko, T., Ong, J.S.-J., Liu, W.K., Kennedy, J.M., 1984. Hourglass control in linear and nonlinear problems. Computer Methods in Applied Mechanics and Engineering, vol. 43, pp. 251-276.
  • [4] Braun, A.L., 2007. Simulação Numérica na Engenharia do Vento Incluindo Efeitos de Interação Fluido-Estrutura. D.Sc. Thesis, PPGEC/UFRGS, Porto Alegre, Brasil.
  • [5] Braun, A.L., Awruch, A.M., 2009. Aerodynamic and aeroelastic analyses on the CAARC standard tall building model using numerical simulation. Computers and Structures, vol. 87, pp. 564-581.
  • [6] Ca, V.T., Asaeda, T., Ito, M., Armfield, S., 1995. Characteristics of wind field in a street canyon. Journal of Wind Engineering and Industrial Aerodynamics, vol. 57, pp. 63-80.
  • [7] Cheng, W.C., Liu, C-H., 2011. Large-eddy simulation of turbulent transports in urban street canyons in different thermal stabilities. Journal of Wind Engineering and Industrial Aerodyanmics, vol. 99, pp. 434-442.
  • [8] Chorin, A.J., 1967. A numerical method for solving incompressible viscous flow problems. Journal of Computational Physics, vol. 2, pp. 12-26.
  • [9] Christon, M.A., 1997. A domain-decomposition message-passing approach to transient viscous incompressible flow using explicit time integration. Computer Methods in Applied Mechanics and Engineering, vol. 148, pp. 329-352.
  • [10] Findikakis, A.N., Street, R.L., 1982. Mathematical description of turbulent flows. Journal of the Hydraulics Division – ASCE, vol. 108, pp. 887-903.
  • [11] Germano, M., Piomelli, U., Moin, P., Cabot, W.H., 1991. A dynamic subgrid-scale eddy viscosity model. Physics of Fluids, vol. A3, pp. 1760-1765.
  • [12] Ghia, U., Ghia, K.N., Shin, C.T., 1982. High-Re Solutions for Incompressible Flow Using the Navier-Stokes Equations and a Multigrid Method. Journal of Computational Physics, vol. 48, pp. 387-411.
  • [13] Kastner-Klein, P., Plate, E.J., 1999. Wind-tunnel study of concentration fields in street canyons. Atmospheric Environment, vol. 33, pp. 3973-3979.
  • [14] Kawahara, M. e Hirano, H., 1983. A finite element method for high Reynolds number viscous fluid flow using two step explicit scheme. International Journal for Numerical Methods in Fluids, vol. 3, pp. 137-163.
  • [15] Kim, J-J and Baik, J-J., 1999. A numerical study of thermal effects on flow and pollutant dispersion in urban street canyons. Journal of Applied Meteorology, vol. 38, pp. 1249- 1261.
  • [16] Li, X.X., Koh, T.Y., Britter, R., Liu, C.H., Norford, L.K., Entekhabi, D., Leung, D.Y.C., 2009. Large-eddy simulation of flow field and pollutant dispersion in urban street canyons under unstable stratification. In: Proceeding of the 7th International Conference on Urban Climate (ICUC-7), Yokohama, Japan.
  • [17] Li, X.X., Liu, C.H., Leung, D.Y.C., Lam, K.M., 2006. Recent progress in CFD modelling of a wind field and pollutant transport in street canyons. Atmospheric Environment, vol. 40, pp. 5640-5658.
  • [18] Lilly, D.K., 1992. A proposed modification of the Germano subgrid-scale closure method. Physics of Fluids, vol. 4, pp. 633-635.
  • [19] Liu, C.-H., Barth, M.C., Leung, D.Y.C., 2004. Large-eddy simulation of flow and pollutant transport in street canyons of different building-height-to-street-width ratios. Journal of Applied Meteorology, vol. 43, pp. 1410-1424.
  • [20] Madalozzo, D.M.S., 2012. Simulação Numérica da Dispersão de Poluentes em Zonas Urbanas considerando Efeitos Térmicos. M.Sc. Dissertation, PPGEC/UFRGS, Porto Alegre, Brasil.
  • [21] Nicholson, S.E., 1975. A pollution model for street-level air. Atmospheric Environment, vol. 9, pp. 19-31.
  • [22] Pavageau, M., Schatzmann, M., 1999. Wind tunnel measurements of concentration fluctuations in an urban street canyon. Atmospheric Environment, vol. 33, pp. 3961-3971.
  • [23] Sakakibara, Y., 1996. A numerical study of the effect of urban geometry upon the surface energy budget. Atmospheric Environment, vol. 30, pp. 487–496.
  • [24] Sini, J.-F., Anquetin, S., Mestayer, P.G., 1996. Pollutant dispersion and thermal effects in urban street canyons. Atmospheric Environment, vol. 30, pp. 2659-2677.
  • [25] Smagorinsky, J., 1963. General circulation experiments with the primitive equations I. The basic experiment. Monthly Weather Review, vol. 91, pp. 99-164.
  • [26] Stathopoulos, T., Baskaran, A., 1996. Computer simulation of wind environmental conditions around buildings. Engineering Structures, vol. 18, pp. 876-885.
  • [27] Vardoulakis, S., Fisher, B.E., Pericleous, K., Gonzalez-Flesca, N., 2003. Modelling air quality in street canyons: A review. Atmospheric Environment, vol. 37, pp. 155-182.
  • [28] Xie, X., Huang, Z., Wang, J., Xie, Z., 2005. The impact of solar radiation and street layout on pollutant dispersion in street canyon. Building and Environment, vol. 40, pp. 201-212.
  • [29] Xie, X., Liu, C-H., Leung, D.Y.C., Leung, M.K.H., 2006. Spatial distribution of trafficrelated pollutant concentrations in street canyons. Atmospheric Environment, vol. 40, pp. 6396-6409.
  • [30] Xie, S., Zhang, Y., Qi, L., Tang, X., 2003. Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmospheric Environment, vol. 37, pp. 3213-3224.
Como citar:

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, 2014.
ISSN 2358-0828, DOI 10.5151/meceng-wccm2012-18509

últimos 30 dias | último ano | desde a publicação


downloads


visualizações


indexações