Title: Comparative modelling of a passive release from an L-shaped building using one, two and three-dimensional dispersion models

Authors: A.G. Venetsanos, J.G. Bartzis, J. Wurtz, D.D. Papailiou

Addresses: National Centre for Scientific Research ''Demokritos'', Environmental Research Laboratory, Institute of Nuclear Technology and Radiation, Environmental Protection, 15310 Aghia Paraskevi, Attiki, Greece. National Centre for Scientific Research, Demokritos Environmental Research Laboratory, Institute of Nuclear Technology and Radiation, Environmental Protection, 15310 Aghia Paraskevi, Attiki, Greece. European Commission, Joint Research Centre, Institute for Systems, Informatics and Safety, TP-650, I-21020, Ispra (Va), Italy. University of Patra, Mechanical Engineering Department, Laboratory of Technical Thermodynamics, Patra, Greece

Abstract: A comparative study has been made for the modelling of a passive release from an L-shaped building, in the presence of wind, using dispersion models of various complexities. Selected for the comparison were the one- and two-dimensional shallow layer models DISPLAY-1 and DISPLAY-2 and the full three-dimensional model ADREA-HF, all being part of the Dense Gas Dispersion Code Package, jointly developed by NCSR-DEMOKRITOS and JRC-ISPRA. For the shallow layer models, turbulence is modelled by means of the entrainment velocity concept, while for the three-dimensional model, a one-equation turbulence closure is used, according to which the turbulent kinetic energy conservation equation is solved. Length scales depend on the local and global flow characteristics of the L-shaped building. Concepts of volume porosity and area permeability are used. The pressure drop due to the building is taken into account by adding resistance terms in the shallow momentum equations. For model validation, the EMU-A1 wind tunnel experiment has been selected. The model results are compared against the experimental concentrations, using a statistical evaluation approach. The results clearly demonstrate the applicability of the model ADREA-HF for the present complex topography. For the shallow layer models acceptable results were obtained in CPU times much lower than ADREA-HF. Further improvements of the model for additional entrainment due to the presence of obstacles is necessary.

Keywords: comparative modelling; dispersion modelling; passive release.

DOI: 10.1504/IJEP.2000.000554

International Journal of Environment and Pollution, 2000 Vol.14 No.1/2/3/4/5/6, pp.324-333

Published online: 18 Jul 2003 *

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