A new numerical formulation of gas leakage and spread into a residential space in terms of hazard analysis

• Published in: Journal of hazardous materials 2014-04, Vol.271, p.266-274
• Main Author: Nagaosa, Ryuichi S.
• Format: Article
• Language: English
• Subjects: Air Movements; Applied sciences; Chemical engineering; Computational fluid dynamics; Computational fluid dynamics (CFD); Exact sciences and technology; Extended two-compartment model; Flammable; Flammable gas leakage; Fluid flow; Gas density; Gases; Hazard analysis; Hazardous Substances; Housing; Hydrodynamics; Leakage; Mathematical models; Models, Theoretical; Pollution; Safety; Spreads; Turbulence; Turbulent flow
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.02.033

•A new numerical approach of the spread of leaked gases is proposed.•A computational fluid dynamics technique without a turbulent model is employed.•Numerical solutions without uncertainties produced by turbulent model are shown.•A series of case studies of gas spread is demonstrated. This study proposes a new numerical formulation of the spread of a flammable gas leakage. A new numerical approach has been applied to establish fundamental data for a hazard assessment of flammable gas spread in an enclosed residential space. The approach employs an extended version of a two-compartment concept, and determines the leakage concentration of gas using a mass-balance based formulation. The study also introduces a computational fluid dynamics (CFD) technique for calculating three-dimensional details of the gas spread by resolving all the essential scales of fluid motions without a turbulent model. The present numerical technique promises numerical solutions with fewer uncertainties produced by the model equations while maintaining high accuracy. The study examines the effect of gas density on the concentration profiles of flammable gas spread. It also discusses the effect of gas leakage rate on gas concentration profiles.