Leigh Nash
University of Central Florida
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Journal of Energy Resources Technology-transactions of The Asme | 2017
Leigh Nash; Jennifer L.S. Klettlinger; Subith Vasu
Thermal stability is an important characteristic of alternative fuels that must be evaluated before they can be used in aviation engines. Thermal stability refers to the degree to which a fuel breaks down when it is heated prior to combustion. This characteristic is of great importance to the effectiveness of the fuel as a coolant and to the engines combustion performance. The thermal stability of Sasol IPK, a synthetic alternative to Jet-A, with varying levels of naphthalene has been studied on aluminum and stainless steel substrates at 300 to 400 °C. This was conducted using a spectroscopic ellipsometer to measure the thickness of deposits left on the heated substrates. Ellipsometry is an optical technique that measures the changes in a light beams polarization and intensity after it reflects from a thin film to determine the films physical and optical properties. It was observed that, as would be expected, increasing the temperature minimally increased the deposit thickness for a constant concentration of naphthalene on both substrates. The repeatability of these measurements was verified using multiple trials at identical test conditions. Lastly, the effect of increasing the naphthalene concentration at a constant temperature was found to also minimally increase the deposit thickness.
54th AIAA Aerospace Sciences Meeting | 2016
Batikan Koroglu; Owen Pryor; Jospeh Lopez; Leigh Nash; Subith Vasu
Propanal is an aldehyde intermediate formed during hydrocarbon combustion process. In this paper, we provide ignition delay time measurements behind reflected shock waves for stochiometric (Φ = 1) mixtures of propanal (CH3CH2CHO) and oxygen (O2) in argon bath gas at temperatures of 1100 < T < 1500 K and pressures around 1 atm. The measurements were conducted using the kinetics shock tube facility at UCF. The results were compared to data available in the literature as well as the predictions of three different aldehyde kinetic models. In addition, we used the laser absorption diagnostics for measuring methane (CH4) time-histories behind the reflected shock waves using a continuous wave distributed feedback interband cascade laser centered at 3403.4 nm. Methane concentration time histories were obtained for pyrolysis of propanal at 1300 K and around atmospheric pressures.
Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration Applications; Organic Rankine Cycle Power Systems | 2017
Leigh Nash; Subith Vasu
Thermal stability is an important characteristic of alternative fuels that must be evaluated before they can be used in aviation engines. Thermal stability refers to the degree to which a fuel breaks down when it is heated prior to combustion. This characteristic is of great importance to the effectiveness of the fuel as a coolant and to the engine’s combustion performance. The thermal stability of Sasol IPK, a synthetic alternative to Jet-A, with varying levels of naphthalene has been studied on aluminum and stainless steel substrates at 300 to 400 °C. This was conducted using a spectroscopic ellipsometer to measure the thickness of deposits left on the heated substrates. Ellipsometry is an optical technique that measures the changes in a light beam’s polarization and intensity after it reflects from a thin film to determine the film’s physical and optical properties. It was observed that, as would be expected, increasing the temperature increased the deposit thickness for a constant concentration of naphthalene on both substrates. The repeatability of these measurements was verified using multiple trials at identical test conditions. Lastly, the effect of increasing the naphthalene concentration at a constant temperature was found to also increase the deposit thickness.Copyright
55th AIAA Aerospace Sciences Meeting | 2017
Leigh Nash; Jennifer L.S. Klettlinger; Subith Vasu
Jet fuels are typically used for endothermic cooling in practical engines where their thermal stability is very important. In this work the thermal stability of Sasol IPK (a synthetic jet fuel) with varying levels of naphthalene has been studied on stainless steel substrates using spectroscopic ellipsometry in the temperature range 385-400 K. Ellipsometry is an optical technique that measures the changes in a light beam’s polarization and intensity after it reflects off of a thin film to determine the film’s thickness and optical properties. All of the tubes used were rated as thermally unstable by the color standard portion of the Jet Fuel Thermal Oxidation Test, and this was confirmed by the deposit thicknesses observed using ellipsometry. A new amorphous model on a stainless steel substrate was used to model the data and obtain the results. It was observed that, as would be expected, increasing the temperature of the tube increased the overall deposit amount for a constant concentration of naphthalene. The repeatability of these measurements was assessed using multiple trials of the same fuel at 385 K. Lastly, the effect of increasing the naphthalene concentration in the fuel at a constant temperature was found to increase the deposit thickness.
Combustion and Flame | 2016
Batikan Koroglu; Owen Pryor; Joseph Lopez; Leigh Nash; Subith Vasu
Combustion and Flame | 2018
Erik Ninnemann; Batikan Koroglu; Owen Pryor; Samuel Barak; Leigh Nash; Zachary Loparo; Jonathan Sosa; Kareem Ahmed; Subith Vasu
Journal of Energy Resources Technology-transactions of The Asme | 2017
Owen Pryor; Samuel Barak; Joseph Lopez; Erik Ninnemann; Batikan Koroglu; Leigh Nash; Subith Vasu
51st AIAA/SAE/ASEE Joint Propulsion Conference | 2015
Batikan Koroglu; Owen Pryor; Joseph Lopez; Leigh Nash; Subith Vasu
52nd AIAA/SAE/ASEE Joint Propulsion Conference | 2016
Owen Pryor; Ghazal Barari; Batikan Koroglu; Joseph Lopez; Leigh Nash; Subith Vasu
Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems | 2018
Leigh Nash; Jennifer L.S. Klettlinger; Subith Vasu