Methane oxidation behind reflected shock waves: ignition delay times measured by pressure and flame band emission

Conference · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5750392

Brabbs, T A; Robertson, T F

Ignition delay data were recorded for three methane-oxygen-argon mixtures (phi = 0.5, 1.0, 2.0) for the temperature range 1500 to 1920 K. Quiet pressure trances enabled us to obtain delay times for the start of the experimental pressure rise. These times were in good agreement with those obtained from the flame band emission at 3700 A. The data correlated well with the oxygen and methane dependence of Lifshitz, but showed a much stronger temperature dependence (phi = 0.5 delta E = 51.9, phi = 1.0 delta = 58.8, phi = 2.0 delta E = 58.7 Kcal). The effect of probe location on the delay time measurement was studied. It appears that the probe located 83 mm from the reflecting surface measured delay times which may not be related to the initial temperature and pressure. It was estimated that for a probe located 7 mm from the reflecting surface, the measured delay time would be about 10 microseconds too short, and it was suggested that delay times less than 100 microsecond should not be used. The ignition period was defined as the time interval between start of the experimental pressure rise and 50 percent of the ignition pressure. This time interval was measured for three gas mixtures and found to be similar (40 to 60 micro sec) for phi = 1.0 and 0.5 but much longer (100 to 120) microsecond for phi = 2.0. It was suggested that the ignition period would be very useful to the kinetic modeler in judging the agreement between experimental and calculated delay times.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• OSTI ID: 5750392
• Report Number(s): N-86-21635; NASA-TM-87268; E-2956; CONF-860536-1
• Resource Relation: Conference: Technical meeting on fluid mechanics and chemistry of the combustion process, Cleveland, OH, USA, 5 May 1986
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ARGON
IGNITION
METHANE
OXYGEN
EMISSION SPECTRA
EXPERIMENTAL DATA
MIXTURES
OXIDATION
PRESSURE MEASUREMENT
SHOCK TUBES
TEMPERATURE DEPENDENCE
ALKANES
CHEMICAL REACTIONS
DATA
DISPERSIONS
ELEMENTS
FLUIDS
GASES
HYDROCARBONS
INFORMATION
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
RARE GASES
SPECTRA
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry