Simulations of Contaminant Dispersion from Accidental Releases in     Cities: A CFD Approach / Simulacije širenja zagađujućih materija uslijed    nenamjernih ispuštanja u gradovima: CFD pristup

Energija, ekonomija, ekologija, 1, XXVIII (2026) (24-30 стр.)

АУТОР(И) / AUTHOR(S): Mahir Hafizović , Muhamed Hadžiabdić , Bojan Ničeno

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DOI: https://doi.org/10.46793/EEE26-1.24H

САЖЕТАК / ABSTRACT:

Accidental releases of hazardous airborne contaminants in urban environments present a significant challenge for emergency response, risk assessment, and public safety, particularly in scenarios involving toxic or radiological substances. Accurate prediction of contaminant transport in densely built areas requires numerical tools capable of capturing the complex flow structures induced by urban geometry. Computational Fluid Dynamics (CFD) is widely used for this purpose, but its predictive accuracy depends strongly on the choice of turbulence modelling approach. This study evaluates hybrid RANS–LES (HRL) approach, for simulating contaminant dispersion from ground-level accidental releases in a realistic urban layout based on the wind tunnel experiment. Pollutant transport is analysed using mean and instantaneous flow and concentration fields, as well as experimental profiles, with particular emphasis on lateral spreading into adjacent streets, courtyards, and recirculation zones. Results show that HRL resolves unsteady vortex structures, producing pollutant transport patterns that closely match experimental observations. These findings underscore the importance of scale-resolving turbulence models for reliable prediction of accidental contaminant dispersion in urban areas and highlight the critical role of CFD in urban air quality assessment, emergency preparedness, and risk-informed decision-making.

КЉУЧНЕ РЕЧИ / KEYWORDS:

Contaminant dispersion, Accidental releases, Urban air quality, Turbulence modelling, Computational Fluid Dynamics (CFD)

ПРОЈЕКАТ / ACKNOWLEDGEMENT:

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