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Combustion rate limits of hydrogen plus hydrocarbon fuel: Air diffusion flames from an opposed jet burner techniqueCombustion of H2/hydrocarbon (HC) fuel mixtures may be considered in certain volume-limited supersonic airbreathing propulsion applications. Effects of HC addition to H2 were evaluated, using a recent argon-bathed, coaxial, tubular opposed jet burner (OJB) technique to measure the extinction limits of counterflow diffusion flames. The OJB flames were formed by a laminar jet of (N2 and/or HC)-diluted H2 mixture opposed by a similar jet of air at ambient conditions. The OJB data, derived from respective binary mixtures of H2 and methane, ethylene, or propane HCs, were used to characterize BLOWOFF and RESTORE. BLOWOFF is a sudden breaking of the dish-shaped OJB flame to a stable torus or ring shape, and RESTORE marks sudden restoration of the central flame by radial inward flame propagation. BLOWOFF is a measure of kinetically-limited flame reactivity/speed under highly stretched, but relatively ideal impingement flow conditions. RESTORE measures inward radial flame propagation rate, which is sensitive to ignition processes in the cool central core. It is concluded that relatively small molar amounts of added HC greatly reduce the reactivity characteristics of counterflow hydrogen-air diffusion flames, for ambient initial conditions.
Document ID
Document Type
Conference Paper
Pellett, Gerald L. (NASA Langley Research Center Hampton, VA, United States)
Guerra, Rosemary (NASA Langley Research Center Hampton, VA, United States)
Wilson, Lloyd G. (NASA Langley Research Center Hampton, VA, United States)
Reeves, Ronald N. (NASA Langley Research Center Hampton, VA, United States)
Northam, G. Burton (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 13, 2013
Publication Date
October 1, 1987
Publication Information
Publication: Johns Hopkins Univ., The 24th JANNAF Combustion Meeting, Volume 2
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.