Title: Well mixed condition verification in windy and low wind speed conditions

Authors: Domenico Anfossi, Gianni Tinarelli, Silvia Trini Castelli, Enrico Ferrero, Dietmar Oettl, Gervasio Annes Degrazia, Luca Mortarini

Addresses: C.N.R., Istituto di Scienze dell'Atmosfera e del Clima, Corso Fiume 4, 10133 Torino, Italy. ' ARIANET, Milano, Italy. ' C.N.R., Istituto di Scienze dell'Atmosfera e del Clima, Corso Fiume 4, 10133 Torino, Italy. ' Dipartimento di Scienze e Tecnologie Avanzate, Universita' del Piemonte Orientale 'A. Avogadro', Via Bellini, 25/G, Alessandria, Italy. ' Institute for Internal Combustion Engines and Thermodynamics, Graz University of Technology, Graz, Austria. ' Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. ' Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale, Alessandria, Italy

Abstract: Dispersion in low wind speed conditions is governed by meandering that disperses plumes over wide angular sectors, thus g.l.c. are lower than predicted by Gaussian models. It was proposed to model these dispersion situations in homogeneous conditions with two coupled Langevin equations, based on low wind speed turbulence analysis. Their parameters were derived from the autocorrelation functions of horizontal wind that exhibit an oscillations and large negative lobes. We propose a new equation system for: general case of inhomogeneous turbulence; total velocity; for the windy situations (based on the ||Thomson simplest solution||) and verify that these new solutions satisfy the ||well-mixed condition||.

Keywords: LWS; low wind speed; dispersion modelling; Langevin equations; meandering; well-mixed condition; air pollution; pollutant dispersion; air quality; turbulence analysis.

DOI: 10.1504/IJEP.2010.030882

International Journal of Environment and Pollution, 2010 Vol.40 No.1/2/3, pp.49 - 61

Published online: 11 Jan 2010 *

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