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Microgravity n-Heptane Droplet Combustion in Oxygen-Helium Mixtures at Atmospheric Pressure

Published on Jan 1, 1998in AIAA Journal1.951
· DOI :10.2514/2.557
Vedha Nayagam15
Estimated H-index: 15
,
John B. Haggard5
Estimated H-index: 5
+ 4 AuthorsForman A. Williams54
Estimated H-index: 54
Abstract
Results are presented from experiments on the combustion of freely floated n-heptane droplets in helium-oxygen environments conducted in Spacelab onboard the Space Shuttle Columbia during the first launch (STS-83) of the Microgravity Science Laboratory mission in April 1997. During this shortened flight, a total of eight droplets were burned successfully in nominally 300 K oxygen-helium atmospheres having oxygen mole fractions of 25, 30, and 35% at a total pressure of 1 atm. Initial droplet sizes ranged from about 2 to 4 mm. The results demonstrated both radiative and diffusive flame extinction during burning, whereas droplet surface regression followed the d-square law. The full range of possible droplet-burning behaviors was thus observed. The results provide information for testing future theoretical and computational predictions of burning rates, soot and flame characteristics, and extinction conditions.
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