The DVS model: a new concept for heavy gas dispersion by water curtain

Numerous accidents involving dangerous substances may unfortunately occur, namely because of the importance of the transport of dangerous materials, of the storage and use of dangerous products on industrial sites. Several kinds of barriers can be used to protect or reduce the consequences of these accidents, such as the water curtains which mitigate the atmospheric dispersion of toxic clouds. Nevertheless, few studies assessing their effectiveness exist and models predicting the concentrations downstream of water curtains are scarce. In this context, a new concept, based on the representation of the water curtain as a Discontinuous Virtual Source is proposed. From this concept, the DVS model aims to predict on one hand the influence of the ‘peacock tail hose’ (vertical and upwards water curtain) on the dispersion of a toxic cloud, on the other hand, to predict the concentrations downwind of the water barrier. The bases of the model are set out and the results of the simulation, are presented and compared with experimental values of an ammonia plume dispersion in presence of the peacock tail spray.