Raman measurement of mixing and finite-rate chemistry in a supersonic hydrogen-air diffusion flame
- Vanderbilt Univ., Nashville, TN (United States). Dept. of Mechanical Engineering
- NASA, Hampton, VA (United States). Langley Research Center
Ultraviolet (UV) spontaneous vibrational Raman scattering and laser-induced predissociative fluorescence (LIPF) from a KrF excimer laser are combined to simultaneously measure temperature, major species concentrations (H[sub 2], O[sub 2], N[sub 2], H[sub 2]O), and OH radical concentration in a supersonic lifted co-flowing hydrogen-air diffusion flame. The axisymmetric flame is formed when a sonic jet of hydrogen mixes with a Mach 2 annular jet of vitiated air. Mean and rms profiles of temperature, species concentrations, and mixture fraction are obtained throughout the supersonic flame. Simultaneous measurements of the chemical species and temperature are compared with frozen chemistry and equilibrium chemistry limits to assess the local state of the mixing and chemistry. Upstream of the lifted flame base, a very small amount of reaction occurs form mixing with hot vitiated air. Downstream of the lifted flame base, strong turbulent mixing leads to sub equilibrium values of temperature and OH concentration. Due to the interaction of velocity and temperature in supersonic compressible flames, the fluctuations of temperature and species concentrations are found to be higher than subsonic flames. Farther downstream, slow three-body recombination reactions result in super equilibrium OH concentrations that depress temperatures below their equilibrium values.
- OSTI ID:
- 6961385
- Journal Information:
- Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 99:1; ISSN CBFMAO; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simultaneous temperature and multispecies measurement in a lifted hydrogen diffusion flame
Simultaneous temperature and multi-species measurement in a lifted hydrogen diffusion flame by a KrF excimer laser
Related Subjects
083000* -- Hydrogen-- Combustion-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
AIRCRAFT
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENGINES
FLUID FLOW
GAS ANALYSIS
HEAT ENGINES
HYDROGEN
HYDROXYL RADICALS
INTERNAL COMBUSTION ENGINES
KINETICS
LASER SPECTROSCOPY
MONITORING
NONMETALS
RADIATIONS
RADICALS
RAMAN SPECTROSCOPY
RAMJET ENGINES
REACTION KINETICS
SPECTROSCOPY
SUPERSONIC FLOW
TEMPERATURE MONITORING
ULTRAVIOLET RADIATION