Stationary-state and oscillatory combustion of hydrogen in a well-stirred flow reactor
The existence of stationary-state and oscillatory ignition phenomena is established in hydrogen oxidation in a jet-stirred, Pyrex glass reactor (0.55 dm/sup 3/). The experimental observations and their numerical interpretation from a detailed kinetic mechanism are reported. Compositions containing 2H/sub 2/ + O/sub 2/, H/sub 2/ + O/sub 2/, and H/sub 2/ + 2O/sub 2/ were investigated at total pressures mainly in the range 10-20 Torr, with brief excursions up to 80 Torr. The vessel temperature was varied between 670 and 790K and mean residence times were controlled in the range 0.7-8.0 s. Reactant temperatures were measured using a very fine thermocouple in the vessel and light output was monitored by photomultiplier. The experimental conditions straddle events at the second limit. Thus criticality and ignition occurs as the vessel temperature is raised under continuous flow of reactants. Ignition is an oscillatory phenomenon at low pressures, and adiabatic temperature changes occur momentarily during it. Increases of vessel temperature cause oscillatory amplitudes to fall and their frequencies to rise. Eventually the oscillations dwindle to a stable stationary state. In certain circumstances there can be an abrupt transition from low frequency to high frequency oscillations. Detailed investigations show that there can be reaction multiplicity and even birhythmicity in the vicinity of these transition points. The dependences of oscillatory reaction on pressure, temperature, and composition are investigated.
- Research Organization:
- Dept. of Physical Chemistry and Centre for Combustion and Energy, The Univ., Leeds, LS2 9JT (GB)
- OSTI ID:
- 6944035
- Journal Information:
- Combust. Flame; (United States), Vol. 73:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROGEN
COMBUSTION KINETICS
HIGH TEMPERATURE
IGNITION
JETS
OXIDATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELEMENTS
KINETICS
NONMETALS
REACTION KINETICS
080800* - Hydrogen- Properties & Composition
400800 - Combustion
Pyrolysis
& High-Temperature Chemistry