Hydrogen jet flames

作者：Molkov Vladimir^*; Saffers Jean Bernard

来源：International Journal of Hydrogen Energy, 2013, 38(19): 8141-8158.

DOI：10.1016/j.ijhydene.2012.08.106

• Hydrogen safety engineering
• Under-expanded jet theory
• Jet flame length
• The similarity law
• Dimensionless correlation
• Flame tip location

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 0.1-90.0 MPa, temperatures 80-300 K, and leak diameters 0.4-51.7 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%-16%) not stoichiometric 29.5%. All three conservative separation distances for jet fire are shown to be longer than separation distance for non-reacting jet.

• 出版日期2013-6-27