Camila P. Costa

Comparison between analytical models to simulate pollutant dispersion in the atmosphere

We present a numerical and statistical comparison between ADMM and GILTT approaches to simulate pollutant dispersion in the Planetary Boundary Layer (PBL). The numerical and statistical comparison of the ADMM and GILTT results confirms the equivalence of these methods. However, the ADMM approach is more efficient under computational point of view regarding the issue of computational time and, therefore, is more appropriate to be used as an operational air pollution model.

APLICAÇÃO DO MÉTODO GIADMT NA DISPERSÃO DE POLUENTES SOB CONDIÇÃO DE VENTO FRACO

Resumo Objetiva-se criar um modelo matemático que possa estimar a concentração de poluentes na atmosfera sob condições de vento fraco. Essa modelagem será realizada através da resolução analítica da equação de difusão-advecção tridimensional, sob a condição de vento fraco utilizando o método GIADMT. Para investigar a performance do modelo, os resultados serão confrontados com dados experimentais existentes na literatura.

Simulation of the Dispersion of Pollutants Considering Nonlocal Effects in the Solution of the Advection-Diffusion Equation

A way to solve the problem of closing the advection-diffusion equation is based on the transport hypothesis by gradient that, in analogy with molecular diffusion, assumes that the turbulent flux of concentration is proportional to the magnitude of the gradient of medium concentration. This work differs from the traditional method; a generic equation is used for the turbulent diffusion being considered that the flux more yours derived is proportional to the medium gradient. This way, an equation is obtained that takes into account the asymmetry in the process of dispersion of atmospheric pollutants. Therefore, the proposal of this work is to obtain an analytic solution of this new equation using the Laplace Transform technique, considering the Convective Boundary Layer (CBL) as a multilayer system. To investigate the influence of the nonlocal effects in the turbulent dispersion process, the model is evaluated against atmospheric dispersion experiments that were carried out in Copenhagen under unstable conditions.

Poster 23 The new GIADMT approach to simulate the pollutant dispersion in the planetary boundary layer

Abstract Analytical solutions of equations are of fundamental importance in understanding and describing the phenomenon of turbulent diffusion in the atmosphere. Focusing our attention in this direction, in this work we report a semi-analytical solution for the three-dimensional advection–diffusion equation in order to simulate pollutant dispersion in the atmosphere considering a vertically inhomogeneous PBL. This work relies on the semi-analytical solution for the three-dimensional advection–diffusion equation combining the ADMM (Advection Diffusion Multilayer Model) and GITT (Generalized Integral Transform Technique) methods. We coin this technique as GIADMT (Generalized Integral Advection Diffusion Multilayer Technique).