LES of high pressure hydrogen jet fire

Brennan, Síle; Makarov, Dmitriy; Molkov, Vladimir

doi:10.1016/j.jlp.2008.12.007

Cited by 66 publications

(28 citation statements)

References 19 publications

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“…to average axial velocity is 0.25 AE 10% as derived in 1953 by Thring and Newby [9] from experiments of Corrsin [10]. This high level of turbulence in under-expanded jets has been confirmed recently by the application of the large eddy simulation (LES) technique [11] to process experimental data on jet fires by Sandia National Laboratories.…”

mentioning

confidence: 65%

“…The similarity law (11) for concentration decay in a unignited momentum-controlled jets requires the use of hydrogen mass fraction and not volumetric fraction as mistakenly used by some researchers. The mass fraction (C M ) can be calculated by the volumetric (mole) fraction (C V ) by equation 1/C M ¼ 1 þ (1/C V À 1)M S /M N , where M S and M N are molecular mass of surrounding gas and nozzle gas respectively.…”

Section: Separation Distances From a Hydrogen Leakmentioning

confidence: 99%

“…The application of the similarity law (11) to axial concentration decay in expanded jet is straight forward with the use of a constant hydrogen density in a nozzle, e.g. r N ¼ 0.0838 kg/ m 3 at normal temperature and pressure (NTP).…”

mentioning

confidence: 99%

“…11 correspond to the dimensionless distance x/D to location of particular axial hydrogen concentration, C ax , as a function of the density in the nozzle, r N , (recalculated to the storage pressure, p in atmospheres, in Fig. 11) and calculated using the similarity law (11).…”

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confidence: 99%

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Hydrogen jet flames

Molkov

Saffers

2013

International Journal of Hydrogen Energy

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Jet flame length The similarity law Dimensionless correlation Flame tip location a b s t r a c t A critical review and rethinking of hydrogen jet flame research is carried out. Froude number only based correlations are shown to be deficient for under-expanded jet fires. The novel dimensionless flame length correlation is developed accounting for effects of Froude, Reynolds, and Mach numbers. The correlation is validated for pressures 0.1e90.0 MPa, temperatures 80e300 K, and leak diameters 0.4e51.7 mm. Three distinct jet flame regimes are identified: traditional buoyancy-controlled, momentum-dominated "plateau" for expanded jets, and momentum-dominated "slope" for under-expanded jets. The statement "calculated flame length may be obtained by substitution the concentration corresponding to the stoichiometric mixture in equation of axial concentration decay for non-reacting jet"is shown to be incorrect. The correct average value for non-premixed turbulent flames is 11% by volume of hydrogen in air (range 8%e16%) not stoichiometric 29.5%. All three conservative separation distances for jet fire are shown to be longer than separation distance for non-reacting jet.

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mentioning

confidence: 65%

Section: Separation Distances From a Hydrogen Leakmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Hydrogen jet flames

Molkov

Saffers

2013

International Journal of Hydrogen Energy

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“…Turbulence and chemical reactions have also been included using different methods. Simulations of hydrogen safety problems were performed by Brennan et al [17] and Middha [18], among others. Brennan investigated hydrogen jets using Large Eddy Simulation (LES), and showed that the flame length varied with initial nozzle turbulence.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of DDT in hydrogen–Air behind a single obstacle

Gaathaug

Vaagsaether

Bjerketvedt

2012

International Journal of Hydrogen Energy

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Experimental and numerical studies of premixed methane‐hydrogen/air mixtures flame propagation in closed duct

Zhang

Cao

et al. 2018

Can J Chem Eng

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In order to reveal flame propagation behaviour and the mechanism of premixed methane-hydrogen/air mixtures (PMHAM), a pressure recording device was used for testing explosion pressure with different volume fractions of methane-hydrogen in a closed duct. Results showed that the explosion pressure and pressure rise rate increased with volume fraction up to an optimum fraction of 10 % for a maximum explosion pressure (P max ) of 0.60 MPa and a pressure rise rate ((dP/dt) max ) of 54.93 MPa/s. Meanwhile, a high-speed video camera was used for testing flame propagation behaviour with the optimum fraction. Results showed that the flame propagation process consisted four dynamic stages-spherical flame, finger-shape flame, flame touching sidewalls, and tulip flame. Comparison of the numerical and experimental results showed reasonable qualitative and quantitative agreement. Additionally, the numerical simulation was used for addressing technical difficulties of understanding the mechanism of flame propagation. The simulated results confirmed the existence of two large-scale vortices nearby sidewalls generated by the gas-flow reflection and back-streaming; these increased vortices made speed of the flame front touching sidewalls exceed that of the middle, which ultimately resulted in reversal of flame front. This meant that the interactions of gas-flow reflection, back-streaming, and vortex motions were the immediate reason of tulip flame.

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LES of high pressure hydrogen jet fire

Cited by 66 publications

References 19 publications

Hydrogen jet flames

Hydrogen jet flames

Experimental and numerical investigation of DDT in hydrogen–Air behind a single obstacle

Experimental and numerical studies of premixed methane‐hydrogen/air mixtures flame propagation in closed duct

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