Ignition of lean fuel-air mixtures in a premixing-prevaporizing duct at temperatures up to 1000K

Technical Report · Mon Dec 01 04:00:00 EST 1980

OSTI ID:6877800

Tacina, R R

Conditions were determined in a premixing-prevaporizing fuel preparation duct at which ignition occurred. An air-blast-type fuel injector with nineteen fuel injection points was used to provide a uniform spatial fuel-air mixture. The range of inlet conditions where ignition occurred were: inlet air temperatures of 600 to 1000/sup 0/K, air pressures of 180 to 660 kPa, equivalence ratios (fuel-air ratio divided by stoichiometric fuel-air ratio) from 0.13 to 1.05, and velocities from 3.5 to 30 m/s. The duct was insulated and the diameter was 12 cm. Mixing lengths were varied from 16.5 to 47.6 cm and residence times ranged from 4.6 to 107 ms. The fuel was No.2 diesel. Results showed a strong effect of equivalence ratio, pressure and temperature on the conditions where ignition occurred. The data did not fit the most commonly used model of autoignition. In particular, the effect of length or residence time on ignition delay is not clear in these tests. A correlation of the conditions where ignition would occur which apply to this test apparatus over the conditions tested is (p/V)phi/sup 1/ /sup 3/ = 0.62 e/sup 2800/T/ where p is the pressure in kPa, V is the velocity in m/s, phi is the equivalence ratio, and T is the temperature in K. The data scatter was considerable, varying by a maximum value of 5 at a given temperature and equivalence ratio. There was a wide spread in the autoignition data contained in the references. The data from this report are in reasonable agreement with those of the references.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• DOE Contract Number: AI01-77CS51040
• OSTI ID: 6877800
• Report Number(s): DOE/NASA/51040-19; NASA-TM-81645
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000 -- Petroleum-- Combustion
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330800* -- Emission Control-- Alternative Fuels
AUTOMOBILES
AUTOMOTIVE FUELS
DATA
DIESEL FUELS
ENGINES
EXPERIMENTAL DATA
FLASHBACK
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
FUELS
GAS TURBINE ENGINES
HEAT ENGINES
IGNITION
INFORMATION
INTERNAL COMBUSTION ENGINES
NUMERICAL DATA
PETROLEUM PRODUCTS
PRESSURE DEPENDENCE
STIRLING ENGINES
TEMPERATURE DEPENDENCE
VEHICLES