On the Modelling of Dispersive Mixing of Flammable Material in Partial Confined Environment

When a fluid (gas) which is lighter or heavier than its surroundings is accidentally released in a chemical process area, the motion of the cloud is governed by the rate at which it entrains the ambient fluid. On the other hand, the dilution of the cloud is dictated by the rate at which air entrains the plume. The geometrical aspects of the process area where the release occurs, the leak rate, the wind speed and direction as well as the leak direction also play a significant role in the final volume of the cloud. A model is presented in which it is considered the grouping of the key variables as a function of the non-dimensional release direction. This model predicts that the non-dimensional cloud size behaves in a wave like fashion and the maximum cloud size is strongly related to the non-dimensional leak direction. The stochastic behaviour of the leak size is also taken into account and it is combined with the model proposed in a novel Monte Carlo simulator. The in house code considers the leak frequency, wind data distribution, leak rates and probabilities of ignition to calculate the exceedance curves based on accurate CFD data.