Workbook of atmospheric dispersion estimates

50 years of Computational Wind Engineering: Past, present and future

Wind comfort and wind safety for pedestrians are important requirements in urban areas. Many city authorities request studies of pedestrian wind comfort and wind safety for new buildings and new urban areas. These studies involve combining statistical meteorological data, aerodynamic information and criteria for wind comfort and wind safety. Detailed aerodynamic information can be obtained using Computational Fluid Dynamics (CFD), which offers considerable advantages compared to wind tunnel testing. However, the accuracy and reliability of CFD simulations can easily be compromised. For this reason, several sets of best practice guidelines have been developed in the past decades. Based on these guidelines, this paper presents a general simulation and decision framework for the evaluation of pedestrian wind comfort and wind safety in urban areas with CFD. As a case study, pedestrian wind comfort and safety at the campus of Eindhoven University of Technology are analysed. The turbulent wind flow pattern over the campus terrain is obtained by solving the 3D steady Reynolds-averaged Navier-Stokes equations with the realisable [email protected] model on an extensive high-resolution grid based on grid-convergence analysis. The simulation results are compared with long-term and short-term on-site wind speed measurements. Wind comfort and wind safety are assessed and potential design improvements are evaluated. The framework and the case study are intended to support and guide future studies of wind comfort and wind safety with CFD and, this way, to contribute to improved wind environmental quality in urban areas.

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CFD simulation for pedestrian wind comfort and wind safety in urban areas: General decision framework and case study for the Eindhoven University campus

CFD Simulation of Near-Field Pollutant Dispersion in the Urban Environment: A Review of Current Modeling Techniques

Wind flow in urban environments is an important factor governing the dispersion of heat and pollutants from streets, squares and buildings. This paper presents a coupled CFD modelling approach for urban wind flow and indoor natural ventilation. A specific procedure is used to efficiently and simultaneously generate the geometry and the high-resolution body-fitted grid for both the outdoor and indoor environment. This procedure allows modelling complex geometries with full control over grid quality and grid resolution, contrary to standard semi-automatic unstructured grid generation procedures. It also provides a way to easily implement various changes in the model geometry and grid for parametric studies. As a case study, a parametric analysis of natural ventilation is performed for the geometrically complex Amsterdam ArenA stadium in the Netherlands. The turbulent wind flow and temperature distribution around and inside the stadium are solved with the 3D steady Reynolds-averaged Navier-Stokes equations. Special attention is given to CFD solution verification and validation. It is shown that small geometrical modifications can increase the ventilation rate by up to 43%. The coupled modelling approach and grid generation procedure presented in this paper can be used similarly for future studies of wind flow and related processes in complex urban environments.

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X. Wang

Papers

Numerical evaluation of pollutant dispersion in the built environment: comparisons between models and experiments