A model based on similarity transformation, for the nitrogen-diluted, H2-air opposed-jet laminar counterflow diffusion flame (CFDF), was developed independently of earlier models, and numerically solved to study flame location and flame structure and extinction limits. Numerical stiffness is handled by a special treatment of the species production term. Flame location with respect to the stagnation plane is identified as an important parameter that governs H2-air diffusion flames, and physical explanations are given to show how flame location is affected by fuel dilution, strain rate, and Lewis number. Results show very good agreement with experimental extinction conditions. The effect of thermal diffusion on the flame is found to be negligible. The simpler, constant Lewis number model produced extinction at half the strain rate compared to the species-dependent Lewis number model. The hydrogen-air CFDF exhibits several characteristics not observed for hydrocarbon flames. The underlying reasons are discussed in terms of the fluid dynamic and chemical kinetic aspects.


Mechanical and Aerospace Engineering

Publication Status

Full Access

International Standard Serial Number (ISSN)

1533-3876; 0748-4658

Document Type

Article - Journal

Document Version


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Publication Date

01 Jan 1996