Multi-obstacles Influence on High-Pressure Methane Jets

Accidental high-pressure unignited jets of methane are one of the most dangerous scenarios investigated in industrial risk analysis. Considering a typical industrial plant, it is common that during the dispersion of a flammable gas cloud it interacts with one or more obstacles like buildings or equipment (e.g., columns, tanks, pipe rack, etc.); such interaction could significantly change the relevant damage areas. Due to this, in the industrial safety framework, empirical integral models elaborating only the free jet scenario could resolve in unreliable evaluations. Assuming the importance to correctly approach the scenario of a jet interacting with a series of obstacles the only numerical model able to properly evaluate any obstacle influence is the Computational Fluid Dynamics (CFD). The aim of this work is to investigate how a series of obstacles, in different configurations, can influence the jet cloud extent. Realistic case-studies of industrial plant are analysed: a stationary jet at various pressure impinging a series of cylindrical vertical tanks placed along the axis release. Sensitivity investigation on the obstacles size and distance is performed with CFD simulations through the software ANSYS® CFX®.