Numerical modelling of dispersion of ammonia and chlorine in urban areas during emergency accident

Abstract

Modelling dispersion and determining the range of a danger zone is usually based on empirical models whose limitations simplify the result. Spreading the cloud in industrial space, urban or other irregular area with numerous obstacles, is impossible to predict using these models. The solution in this situation is the use of numerical modelling. CFD allows for consideration of complex geometry, wind flow between elements, gas weight, turbulence in the atmosphere and mass and heat flow in the test area. Such relations illustrate the phenomenon of dispersion in 3d space in a very accessible way, at the same time they allow to show more precisely the characteristic places of residual gas or fast dispersion. The paper presents the possibilities of using numerical simulations for 3d modelling dispersion of ammonia and chlorine in the densely built urban space of Warsaw.