Modeling and simulation of dense cloud dispersion in urban areas by means of computational fluid dynamics

JOURNAL OF HAZARDOUS MATERIALS

卷:197

Article

Scargiali, F.¹  Grisafi, F.¹  Busciglio, A.¹  Brucato, A.¹ 

[1] Univ Palermo, Dipartimento Ingn Chim Gest Informat & Meccan, I-90128 Palermo, Italy

关键词: Heavy clouds;    Urban canopy;    CFD;    Dispersion modeling;    Complex terrain;   

DOI  :  10.1016/j.jhazmat.2011.09.086

来源: Elsevier

【 摘 要 】

The formation of toxic heavy clouds as a result of sudden accidental releases from mobile containers, such as road tankers or railway tank cars, may occur inside urban areas so the problem arises of their consequences evaluation. Due to the semi-confined nature of the dispersion site simplified models may often be inappropriate. As an alternative, computational fluid dynamics (CFD) has the potential to provide realistic simulations even for geometrically complex scenarios since the heavy gas dispersion process is described by basic conservation equations with a reduced number of approximations. In the present work a commercial general purpose CFD code (CFX 4.4 by Ansys (R)) is employed for the simulation of dense cloud dispersion in urban areas. The simulation strategy proposed involves a stationary pre-release flow field simulation followed by a dynamic after-release flow and concentration field simulations. In order to try a generalization of results, the computational domain is modeled as a simple network of straight roads with regularly distributed blocks mimicking the buildings. Results show that the presence of buildings lower concentration maxima and enlarge the side spread of the cloud. Dispersion dynamics is also found to be strongly affected by the quantity of heavy-gas released. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

Free