Show simple item record

dc.contributor.advisorCizmas, Paul G.en_US
dc.creatorJones, Nathanen_US
dc.date.accessioned2012-10-19T15:31:06Zen_US
dc.date.accessioned2012-10-22T18:05:25Z
dc.date.available2014-11-03T19:49:15Z
dc.date.created2012-08en_US
dc.date.issued2012-10-19en_US
dc.date.submittedAugust 2012en_US
dc.identifier.urihttp://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11858en_US
dc.description.abstractMany reaction mechanisms have been developed over the past few decades to predict flame characteristics. A detailed reaction mechanism can predict flame characteristics well, but at a high computational cost. The reason for reducing reaction mechanisms is to reduce the computational time needed to simulate a problem. The focus of this work is on the validity of reduced methane-air combustion mechanisms, particularly pertaining to satisfying the entropy inequality. While much of this work involves a two-step reaction mechanism developed by Dr. Charles Westbrook and Dr. Frederick Dryer, some consideration is given to the four-step and three-step mechanisms of Dr. Norbert Peters. These mechanisms are used to simulate the Flame A experiment from Sandia National Laboratories. The two-step mechanism of Westbrook and Dryer is found to generate results that violate the entropy inequality. Modifications are made to the two-step mechanism simulation in an effort to reduce these violations. Two new mechanisms, Mech 1 and Mech 2, are developed from the original two-step reaction mechanism by modifying the empirical data constants in the Arrhenius reaction form. The reaction exponents are set to the stoichiometric coefficients of the reaction, and the concentrations computed from a one-dimensional flame simulation are matched by changing the Arrhenius parameters. The new mechanisms match experimental data more closely than the original two-step mechanism and result in a significant reduction in entropy inequality violations. The solution from Mech 1 had only 9 cells that violated the entropy inequality, while the original two-step mechanism of Westbrook and Dryer had 22,016 cells that violated the entropy inequality. The solution from Mech 2 did not have entropy inequality violations. The method used herein for developing the new mechanisms can be applied to more complex reaction mechanisms.en_US
dc.format.mimetypeapplication/pdfen_US
dc.language.isoen_USen_US
dc.subjectmethane combustionen_US
dc.subjectentropy inequalityen_US
dc.subjectreduced reaction mechanismen_US
dc.titleThe Importance of the Entropy Inequality on Numerical Simulations Using Reduced Methane-air Reaction Mechanismsen_US
dc.typeThesisen
thesis.degree.departmentAerospace Engineeringen_US
thesis.degree.disciplineAerospace Engineeringen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelMastersen_US
dc.contributor.committeeMemberKarpetis, Adoniosen_US
dc.contributor.committeeMemberSlattery, Johnen_US
dc.contributor.committeeMemberPasciak, Josephen_US
dc.type.genrethesisen_US
dc.type.materialtexten_US
local.embargo.terms2014-10-22en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record