Shock Tube Study of Nitric Oxide Addition on Ignition Delay Time of n-Dodecane/Air Mixture

Author(s):  
Jiankun Shao ◽  
Yangye Zhu ◽  
Chris Almodovar ◽  
David F. Davidson ◽  
Ronald K. Hanson
2007 ◽  
Vol 20 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Su Wang ◽  
Hua-jie Gou ◽  
Bing-cheng Fan ◽  
Yu-zhong He ◽  
Sheng-tao Zhang ◽  
...  

2020 ◽  
Vol 212 ◽  
pp. 486-499 ◽  
Author(s):  
Andrew R. Laich ◽  
Erik Ninnemann ◽  
Sneha Neupane ◽  
Ramees Rahman ◽  
Samuel Barak ◽  
...  

Shock Waves ◽  
2009 ◽  
pp. 781-785 ◽  
Author(s):  
A. Abdali ◽  
M. Fikri ◽  
H. Wiggers ◽  
C. Schulz

2020 ◽  
Author(s):  
Joshua Hargis ◽  
Sean Cooper ◽  
Olivier Mathieu ◽  
Bing Guo ◽  
Eric L. Petersen

Author(s):  
Owen Pryor ◽  
Batikan Koroglu ◽  
Samuel Barak ◽  
Joseph Lopez ◽  
Erik Ninnemann ◽  
...  

Ignition delay times and methane species time-histories were measured for methane/O2 mixtures in a high CO2 diluted environment using shock tube and laser absorption spectroscopy. The experiments were performed between 1300 K and 2000 K at pressures between 1 and 31 atm. The experimental mixtures were conducted at an equivalence ratio of 1 with CH4 mole fractions ranging from 3.5%–5% and up to 85% CO2 with a bath of argon gas as necessary. The ignition delay times and methane time histories were measured using pressure, emission, and laser diagnostics. Predictive ability of two literature kinetic mechanisms (GRI 3.0 and ARAMCO Mech 1.3) was tested against current data. In general, both mechanisms performed reasonably well against ignition delay time data. The methane time-histories showed good agreement with the mechanisms for most of the conditions measured. A correlation for ignition delay time was created taking into the different parameters showing that the ignition activation energy for the fuel to be 49.64 kcal/mol. Through a sensitivity analysis, CO2 is shown to slow the overall reaction rate and increase the ignition delay time. To the best of our knowledge, we present the first shock tube data during ignition of methane under these conditions. Current data provides crucial validation data needed for development of future methane/CO2 kinetic mechanisms.


Author(s):  
Samuel Barak ◽  
Owen Pryor ◽  
Joseph Lopez ◽  
Erik Ninnemann ◽  
Subith Vasu ◽  
...  

In this study, syngas combustion was investigated behind reflected shock waves in order to gain insight into the behavior of ignition delay times and effects of the CO2 dilution. Pressure and light emissions time-histories measurements were taken at a 2 cm axial location away from the end wall. High-speed visualization of the experiments from the end wall was also conducted. Oxy-syngas mixtures that were tested in the shock tube were diluted with CO2 fractions ranging from 60% to 85% by volume. A 10% fuel concentration was consistently used throughout the experiments. This study looked at the effects of changing the equivalence ratios (ϕ), between 0.33, 0.5, and 1.0 as well as changing the fuel ratio (θ), hydrogen to carbon monoxide, from 0.25, 1.0, and 4.0. The study was performed at 1.61–1.77 atm and a temperature range of 1006–1162 K. The high-speed imaging was performed through a quartz end wall with a Phantom V710 camera operated at 67,065 frames per second. From the experiments, when increasing the equivalence ratio, it resulted in a longer ignition delay time. In addition, when increasing the fuel ratio, a lower ignition delay time was observed. These trends are generally expected with this combustion reaction system. The high-speed imaging showed nonhomogeneous combustion in the system; however, most of the light emissions were outside the visible light range where the camera is designed for. The results were compared to predictions of two combustion chemical kinetic mechanisms: GRI v3.0 and AramcoMech v2.0 mechanisms. In general, both mechanisms did not accurately predict the experimental data. The results showed that current models are inaccurate in predicting CO2 diluted environments for syngas combustion.


2011 ◽  
Vol 33 (1) ◽  
pp. 251-258 ◽  
Author(s):  
K.-Y. Lam ◽  
Z. Hong ◽  
D.F. Davidson ◽  
R.K. Hanson

Author(s):  
Nicole Donato ◽  
Christopher Aul ◽  
Eric Petersen ◽  
Christopher Zinner ◽  
Henry Curran ◽  
...  

One of the alkanes found within gaseous fuel blends of interest to gas turbine applications is butane. There are two structural isomers of butane, normal butane and iso-butane, and the combustion characteristics of either isomer are not well known. Of particular interest to this work are mixtures of n-butane and iso-butane. A shock-tube experiment was performed to produce important ignition delay time data for these binary butane isomer mixtures which are not currently well studied, with emphasis on 50–50 blends of the two isomers. These data represent the most extensive shock-tube results to date for mixtures of n-butane and iso-butane. Ignition within the shock tube was determined from the sharp pressure rise measured at the endwall which is characteristic of such exothermic reactions. Both experimental and kinetics modeling results are presented for a wide range of stoichiometry (φ = 0.3–2.0), temperature (1056–1598 K), and pressure (1–21 atm). The results of this work serve as validation for the current chemical kinetics model. Correlations in the form of Arrhenius-type expressions are presented which agree well with both the experimental results and the kinetics modeling. The results of an ignition-delay-time sensitivity analysis are provided, and key reactions are identified. The data from this study are compared with the modeling results of 100% normal butane and 100% iso-butane. The 50/50 mixture of n-butane and iso-butane was shown to be more readily ignitable than 100% iso-butane but reacts slower than 100% n-butane only for the richer mixtures. There was little difference in ignition time between the lean mixtures.


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