Modelling and Validation of Dispersion following an Instantaneous Release from a Pressurised Vessel

Abstract

This paper presents a new model for the initial dispersion phase of energetic instantaneous expansion following a catastrophic vessel rupture. This model has been implemented as a new sub-model in the Phast dispersion model UDM and is based on sounder physical principles than that included in the current release of Phast. The paper describes the analytical verification and validation of the new model for vapour releases and for two-phase releases without and with rainout. It is demonstrated that the new model agrees better with the available experimental data than the old model.