Introduction

• Modeling of the dispersion of toxic gases, due to accidental releases have tremendous importance in chemical process safety and hazard analysis.
• Traditional dispersion models can be roughly categorized into two types: Integral models and Computational Fluid Dynamics (CFD) models.
• Integral models like Gaussian model, box model, DEGADIS model etc. are fast and easy to implement, but as they do not take terrain conditions and wind fluctuations into account, their accuracy is not reliable in complex terrains or weather conditions.
• On the other hand, CFD models take full terrain conditions into account and shows outstanding accuracy even in complex terrains. But their high computation time make them unsuitable for an emergency response scenario.