NASA Logo, External Link
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed AddThis share icon
 

Record Details

Record 30 of 47506
Soot Formation in Laminar Premixed Ethylene/Air Flames at Atmospheric Pressure. Appendix G
Author and Affiliation:
Xu, F.(Michigan Univ., Dept. of Aerospace Engineering, Ann Arbor, MI United States)
Sunderland, P. B.(Michigan Univ., Dept. of Aerospace Engineering, Ann Arbor, MI United States)
Faeth, G. M.(Michigan Univ., Dept. of Aerospace Engineering, Ann Arbor, MI United States)
Urban, D. L. [Technical Monitor]
Abstract: Soot formation was studied within laminar premixed ethylene/air flames (C/O ratios of 0.78-0.98) stabilized on a flat-flame burner operating at atmospheric pressure. Measurements included soot volume fractions by both laser extinction and gravimetric methods, temperatures by multiline emission, soot structure by thermophoretic sampling and transmission electron microscopy, major gas species concentrations by sampling and gas chromatography, concentrations of condensable hydrocarbons by gravimetric sampling. and velocities by laser velocimetry. These data were used to find soot surface growth rates and primary soot particle nucleation rates along the axes of the flames. Present measurements of soot surface growth rates were correlated successfully by predictions based on typical hydrogen-abstraction/carbon-addition (HACA) mechanisms of Frenklach and co-workers and Colket and Hall. These results suavest that reduced soot surface growth rates with increasing residence time seen in the present and other similar flames were mainly caused by reduced rates of surface activation due to reduced H atom concentrations as temperatures decrease as a result of radiative heat losses. Primary soot particle nucleation rates exhibited variations with temperature and acetylene concentrations that were similar to recent observations for diffusion flames; however, nucleation rates in the premixed flames were significantly lower than in, the diffusion flames for reasons that still must be explained. Finally, predictions of yields of major gas species based on mechanisms from both Frenklach and co-workers and Leung and Lindstedt were in good agreement with present measurements and suggest that H atom concentrations (relevant to HACA mechanisms) approximate estimates based on local thermodynamic equilibrium in the present flames.
Publication Date: Dec 15, 2001
Document ID:
20020087748
(Acquired Nov 29, 2002)
Subject Category: INORGANIC, ORGANIC AND PHYSICAL CHEMISTRY
Document Type: Reprint
Publication Information: Soot Formation in Freely-Propagating Laminar Premixed Flames (ISSN 0010-2180); 232-255; (GDL-GMF-01-01)
Contract/Grant/Task Num: N00014-93-0321; NAG3-1245
Financial Sponsor: NASA Lewis Research Center; Cleveland, OH United States
Office of Naval Research; United States
Organization Source: Michigan Univ.; Dept. of Aerospace Engineering; Ann Arbor, MI United States
Description: 23p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: SOOT; LAMINAR FLOW; ETHYLENE; ATMOSPHERIC PRESSURE; FLAMES; PREMIXED FLAMES; GROWTH; GAS CHROMATOGRAPHY; GAS COMPOSITION; GRAVIMETRY; HYDROCARBONS
Imprint And Other Notes: Repr. from Combustion and Flame (Elsevier Science, Inc), v. 108, 1997 p 471-493
Availability Source: Other Sources
› Back to Top
Find Similar Records
NASA Logo, External Link
NASA Official: Gerald Steeman
Site Curator: STI Program
Last Modified: August 22, 2011
Contact Us