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Opposed jet diffusion flames of nitrogen-diluted hydrogen vs air - Axial LDA and CARS surveys; fuel/air rates at extinctionAn experimental study of H-air counterflow diffusion flames (CFDFs) is reported. Coaxial tubular opposed jet burners were used to form dish-shaped CFDFs centered by opposing laminar jets of H2/N2 and air in an argon bath at 1 atm. Jet velocities for extinction and flame restoration limits are shown versus input H2 concentration. LDA velocity data and CARS temperature and absolute N2, O2 density data give detailed flame structure on the air side of the stagnation point. The results show that air jet velocity is a more fundamental and appropriate measure of H2-air CFDF extinction than input H2 mass flux or fuel jet velocity. It is proposed that the observed constancy of air jet velocity for fuel mixtures containing 80 to 100 percent H2 measure a maximum, kinetically controlled rate at which the CFDF can consume oxygen in air. Fuel velocity mainly measures the input jet momentum required to center an H2/N2 versus air CFDF.
Document ID
19890059524
Document Type
Conference Paper
Authors
Pellett, G. L. (NASA Langley Research Center Hampton, VA, United States)
Northam, G. B. (NASA Langley Research Center Hampton, VA, United States)
Wilson, L. G. (NASA Langley Research Center Hampton, VA, United States)
Jarrett, Olin, Jr. (NASA Langley Research Center Hampton, VA, United States)
Antcliff, R. R. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 14, 2013
Publication Date
July 1, 1989
Subject Category
INORGANIC AND PHYSICAL CHEMISTRY
Report/Patent Number
AIAA PAPER 89-2522
Distribution Limits
Public
Copyright
Other