Numerical study on the initial expansion of two-phase cloud from an instantaneous release

In industries some dangerous liquefied gases may accidentally release and it may form a flammable or toxic mixture after mixing with air. One tool that is being developed in industry for two-phase cloud dispersion modeling is computational fluid dynamics (CFD). In this paper, the dispersion processes of different dangerous materials including liquefied chlorine, liquefied ammonia and liquefied petroleum gas were simulated in the same condition to analyze the characteristics of the initial expansion processes by CFD tool. The heat and mass transfer between droplets and the vapor after an instantaneous release event was calculated by using the Eulerian–Lagrangian method. The results from a number of 3-D CFD based studies were compared with the available small-scale experimental results. The results show that the present model and numerical simulation are reliable.

► We provide a successful application of CFD approach to study an instantaneous release. The characteristics of initial expansion are studied by simulated results.
► An experimental case is simulated for different material.
► An initial expansion stage of first 0.3–0.4 s can be identified from calculated results.