Matthew DeWitt
University of Dayton
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Featured researches published by Matthew DeWitt.
14th AIAA/AHI International Space Planes and Hypersonics Systems Technologies Conference | 2006
Tim Edwards; Wright-Patterson Afb; Matthew DeWitt; Linda Shafer; David Brooks; He Huang; Sean P. Bagley; Jorge O. Oña; Mary J. Wornat
The reactivity and deposition characteristics of a specification jet fuel (Jet A-1) and synthetic jet fuel produced via the Fischer-Tropsch (F-T) process were investigated under supercritical pyrolytic conditions. The latter fuel was comprised solely of straight-chain and branched paraffins. It was found that the F-T fuel was significantly more reactive and more prone to deposit formation than the Jet A-1. These results for the F-T fuel were attributed to the lack of hydrogen-donor capacity and high kinetic chain length. Overall, the decomposition pathways were consistent with free radical pyrolysis at elevated pressures and moderate temperatures. Analytical measurements support the hypothesis that cyclic unsaturates and polycyclic aromatic hydrocarbons (PAH) are formed as intermediates of the deposition process under these reaction conditions. Following initial thermal cracking, the formation of larger PAHs and deposits occur via addition of low molecular weight hydrocarbons and PAH-PAH reactions.
43rd AIAA Aerospace Sciences Meeting and Exhibit | 2005
Scott Stouffer; Benjamin M. Mortimer; David Ostdiek; Matthew DeWitt; Robert Pawlik; Richard Reich; Charles W. Frayne; Wright-Patterson Afb; Howard T. Mayfield; Tyndall Afb
** †† ‡‡ §§ A comprehensive research program involving industry, academia and Government laboratories is developing a fundamental understanding of the complex interactions of fuel additives with the processes leading to particulate matter emissions from military gas turbine engines. The goal of this program is to eventually select promising additive compounds that would reduce particulate matter (PM) emissions. One experimental platform for assessing the performance of additives is the Well-Stirred Reactor (WSR) research combustor at the Air Force Research Laboratory. The WSR provides a unique capability for simulating the chemical kinetics within the primary zone of a gas turbine engine combustor. The current study presents results from six different compounds (nitromethane, nitroethane, nitropropane, cyclohexanone, pyridine, and quinoline) as additives for soot reduction. The effect of the temperature on the chemical kinetics vs. the chemical effect of the additives is addressed for the nitroalkane additives.
49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition | 2011
J. Balagurunathan; Giacomo Flora; Saumitra Saxena; Moshan Kahandawala; Matthew DeWitt; Sukh Sidhu; Edwin Corporan
The ignition delay times in the combustion of jet fuels under fuel-lean conditions provide critical information with regard to the high altitude relight and lean blowout limit (LBO). In this study, the ignition delay times were measured behind reflected shock waves under high pressures and fuel-lean conditions for conventional (JP-8), bio-, and Fischer−Tropsch��~ FT) processed alternate jet fuels. In addition, the ignition delay of several hydrocarbons proposed as components in surrogate jet-fuels - n-heptane, n-dodecane (the normal paraffinic component), m-xylene (the aromatic component), and a blend of n- dodecane and m-xylene (77:23 (liquid vol. %)) - was investigated. One of the primary goals of this study was to evaluate the feasibility of the tested alternate fuels as drop-in replacements for conventional jet fuels. This required an understanding of how differences in fuel composition could affect the ignition characteristics. As a first step, only the chemical ignition delay was considered, and therefore, the fuels were pre-vaporized and pre-mixed prior to ignition. Two single-pulse shock tubes, one heated and another non-heated, were used to obtain the current data set. The experimental conditions covered a temperature range of approximately 1000-1600 K, at a pressure of about 18 (±10%) atm, and at an equivalence ratio of 0.5, using argon as the diluent (93%, volume). The preliminary results show an indiscernible difference between ignition delay times of JP-8, the bio-and FT- processed jet-fuels, n-heptane, n-dodecane and the n-dodecane / m-xylene blend under the fuel-lean conditions of this study over the temperature range investigated. However, the ignition delay times of pure m-xylene were significantly longer under identical conditions. The SERDP kinetic model developed under the Strategic Environmental Research and Development Program (SERDP) was used to simulate the ignition delay times for the single component hydrocarbons and the n-dodecane / m-xylene blend. The SERDP model includes the JetSurf 0.2 mechanism as one of the sub-mechanisms. The sensitivity and reaction path analyses indicate the dominance of light hydrocarbon oxidation chemistry (mainly, C 1-C3) in the pre-ignition reaction domain under fuel-lean conditions irrespective of the parent reactant alkane tested. Preliminary results for sensitivity analysis of the blend indicate that even in the presence of an aromatic like m-xylene, the pre-ignition chemistry of the blend is essentially that of oxidation of n-dodecane fragmentation products since large n-alkanes are a major component in most of these fuels. Therefore, fast fragmentation and oxidation of
40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit | 2004
Tim Edwards; Don Minus; William Harrison; Edwin Corporan; Matthew DeWitt; Steven Zabarnick; Lori M. Balster
40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit | 2004
Tim Edwards; William Harrison; Steven Zabarnick; Matthew DeWitt; C. Bentz
Archive | 2008
Richard C. Striebich; Linda Shafer; Matthew DeWitt; Zachary J. West; Tim Edwards; William Harrison
55th AIAA Aerospace Sciences Meeting | 2017
Edwin Corporan; James T. Edwards; Scott Stouffer; Matthew DeWitt; Zachary J. West; Christopher Klingshirn; Christopher R. Bruening
Archive | 2016
Steven Zabarnick; Matthew DeWitt; Richard C. Striebich; Thusitha S. Gunasekera; Jamie S. Ervin; Alejandro M. Briones; Linda Shafer; Shiral K Fernando; John L. Graham; Zachary J. West; Scott Stouffer; Marlin D. Vangsness; Barbara A. Harruff-Miller
Archive | 2016
Tonghun Lee; Steven Zabarnick; Scott Stouffer; Matthew DeWitt
Archive | 2016
Josh Heyne; Matthew DeWitt; Steven Zabarnick; Alex Briones; Scott Stouffer; Tonghun Lee