CLOUD: A vapour-aerosol dispersion model accounting for plume 3D motion and heat and mass transfer between phases

摘要

The CLOUD (concentration levels of unconfined dispersion) code has been developed, the nucleus of which is an innovative two-phase fluid dispersion model characterized by conservation equations for mass, momentum, energy and species, averaged over a volume slice transverse to the direction of plume motion. The initial and boundary conditions for the above equations are determined either by using auxiliary models or by direct input of the space distribution, and respectively of the time evolution, of the relevant variables. The initial conditions model for an instantaneous, puff release has been based on an experimental programme carried out at the Swiss Federal Institute of Technology. The boundary conditions for semi-continuous, jet releases have been based on literature models for critical two-phase flow at the rupture. The code has been validated with data from three large scale release test series: the Desert Tortoise series (ammonia), the Goldfish series (HF), and the Thorney Island series (heavy gas).