Turbulent Buoyant Jet of a Low-Density Gas Leaks into High-Density Ambient: Hydrogen Leakage in Air

摘要: The low-density gas jet injected into a high-density ambient has particular interest in several industrial applications such as fuel leaks, engine exhaust, diffusion flames, materials processing, well natural phenomena fires and volcanic eruptions. most interesting application of this problem nowaday is the hydrogen leaks air; since when it mixes with air, fire or explosion can result. expected extensive usage increases probability its accidental release from vessel infrastructure. Hydrogen energy much promise new clean to replace fossil fuels; however, leakage considered be an important safety issue serious that researchers must address. may occur loose fittings, o-ring seals, pinholes, vents on hydrogen-containing vehicles, buildings, storage facilities, other hydrogen-based systems. divided two classes, first rapid leak causing combustion, while unignited slow-leak. However, ignited air by some source ignition static electricity (autoignition) any external source. Classic turbulent flame models used model class leakage; cf. (Schefer et al., 2006; Houf & Schefer, 2007; Swain Takeno 2007). This work focused second slow-leaks. Previous introduced boundary layer theory approach concentration adjacent ceiling wall at impinging far regions both planar axisymmetric cases for small-scale El-Amin al. (2008); Kanayama (2009a; 2008). kind buoyant jets ’plume’ classed non-Boussinesq; initial fractional density difference high, which defined as, Δρ0 = (ρ∞ − ρ0) , where ρ0 centerline (density source) ρ∞ density. Generally, binary selected low-densities gases temperature 15◦C, differences are 0.93 H2 Air, 0.86 He− 0.43 CH4 Air 0.06 C2H2 N2. (Crapper Baines, 1977) suggested upper bound applicability Boussinesq approximation Δρ0/ρ∞ 0.05. In general, one say valid small difference, << 1. these invalid equation used. Moreover, discussion classification given (Spiegel Veronis, 1960); M.F. Shuyu Sun King Abdullah University Science Technology (KAUST), Thuwal Kingdom Saudi Arabia 2