Study of combustion and flame processes initiated by IR laser-induced absorption. Annual progress report, January 1, 1978--December 31, 1978

Technical Report · Thu Sep 21 00:00:00 EDT 1978

DOI:https://doi.org/10.2172/6635534· OSTI ID:6635534

Guillory, W A

Preliminary studies involving vibrational energy dispersion in propynal have shown that collisionless R ..-->.. R relaxation times are approximately 3 ..mu..sec below 2000 cm/sup -1/. In the same energy regime, collisionless intramolecular V ..-->.. V appears to be much longer, approximately 40 ..mu..sec, whereas V ..-->.. T is very long (approximately msec) as expected. At higher levels of vibrational excitation (>3000 cm/sup -1/), where the density of vibrational levels is much greater, it is expected that the internal energy transfer rates will become much faster. The high and low pressure study of methanol have confirmed the origin of characteristic flame components (OH, CH, and C/sub 2/) as well as the initial combustion processes as a function of pressure. The long sought collisional mechanism for C/sub 2/ formation in hydrocarbon systems probably occurs via ..pi..2CH ..-->.. C/sub 2/ + H/sub 2/ as observed in the study of CH/sub 3/OH, CH/sub 3/CN, C/sub 2/H/sub 4/, and c-C/sub 3/H/sub 6/. In the IR photolysis of C/sub 2/H/sub 4/, C/sub 2/ is principally formed at collisionless pressures from a single C/sub 2/H/sub 4/ molecule, whereas its principal formation at collisional pressures is initiated by C = C scission. The low pressure study of CH/sub 3/CN provides a detailed characterization of the stepwise processes occurring during and subsequent to infrared multiphoton absorption. Finally, visible luminescence resulting from the infrared absorption by SO/sub 2/ suggests the first possible IR photolysis of a triatomic molecule.

• Research Organization: Univ. of Utah, Salt Lake City, UT (United States)
• DOE Contract Number: ER-78-S-02-4695
• OSTI ID: 6635534
• Report Number(s): COO-4695-1
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COMBUSTION
RESEARCH PROGRAMS
FLAMES
ALDEHYDES
CARBON DIOXIDE LASERS
ETHYLENE
LASER RADIATION
METHANOL
NITRILES
PHOTOLYSIS
VIBRATIONAL STATES
ALCOHOLS
ALKENES
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
EXCITED STATES
GAS LASERS
HYDROCARBONS
HYDROXY COMPOUNDS
LASERS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
PHOTOCHEMICAL REACTIONS
RADIATIONS
THERMOCHEMICAL PROCESSES
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry