A Gaussian puff model for flashing aerosol releases: Comparison with GRADE data

The Gaussian puff model, SCIPUFF, has been extended to provide a description two-phase aerosol releases of volatile liquids stored under pressure. The dense gas description in SCIPUFF is used to describe the dispersion characteristics, and the homogeneous equilibrium assumption is used to determine the thermodynamic state of the aerosol as the cloud evolves. Model predictions are compared with the data from GRADE (Gas Release Aerosolisation and Dispersion Experiment), in which multiple instantaneous releases of pressured butane and butane/propane mixtures from n x n arrays of pressured vessels were made, where n ranged from 2 to 5. Fast response concentration measurements sampled the cloud at distances up to 300m downstream and compared with the SCIPUFF model predictions. The nonlinear puff overlap calculation in SCIPUFF is used to account for interaction between the multiple releases.