The study of the effect of obstacles on flow and dispersion in the atmospheric boundary layer is one of the most important topics in atmospheric dispersion research. Computational Fluid Dynamics (CFD) methods are increasingly used to predict concentration fields near buildings in an operational context, but extensive validations are still needed. In this paper, we analyse the effect on flow and...

Today, the cement industry is one of the major air polluting industries in the world. Hence, in this study, owing to the importance and role of contaminants from the plant, an appraisal of the emission contributions in addition to other factors have been discussed. There are several reasons behind the importance of modeling air pollutants. First, the assessment of standards for air pollution, a...

Mathematical models for pollutant transport in semi-infinite aquifers are based on the advection-dispersion equation (ADE) and its variants. This study employs the ADE incorporating time-dependent dispersion and velocity and space-time dependent source and sink, expressed by one function. The dispersion theory allows mechanical dispersion to be directly proportional to seepage velocity. Initial...

An analytical solution for the transient two-dimensional atmospheric pollutant dispersion problem is presented. The approach used in this problem utilizes the double GITT (Generalized Integral Transform Technique), the Laplace Transform and the matrix diagonalization. Furthermore, mathematical filters are used due to the existence of non-homogeneous boundary conditions. The results we obtained ...

Although widely used in workplace, indoor and ambient air quality assessments, diffusive sampling has not yet been established as a common tool for dispersion model validation. In this study, three mathematical models (STREET, OSPM and AEOLIUS) that are likely to be used for regulatory purposes were validated against experimental data obtained in two street canyons in Paris. Diffusive tubes wer...

This paper presents experimental and computational investigation of the dispersion mechanisms of a passive-type tracer gas, done in the scaled, three-dimensional model of a street canyon. At a low wind speed of 1.67m/s and neutral atmospheric conditions, dispersion of pollutant has been investigated within an isolated street canyon at an aspect ratio of 1 for perpendicular wind orientation (90)...

Mathematical models for pollutant transport in semi-infinite aquifers are based on the advection-dispersion equation (ADE) and its variants. This study employs the ADE incorporating time-dependent dispersion and velocity and space-time dependent source and sink, expressed by one function. The dispersion theory allows mechanical dispersion to be directly proportional to seepage velocity. Initial...

This paper provides a brief, non-exhaustive overview of the status of the application of CFD in building performance simulation for the outdoor environment. It focuses on four topics: (1) pedestrian wind environment around buildings; (2) wind-driven rain on building facades; (3) convective heat and mass transfer coefficients at building surfaces; and (4) air pollutant dispersion around building...