Ignition delay time measurements for distillate and synthetic jet fuels

Author(s):  
Yu Wang ◽  
Yi Cao ◽  
David F. Davidson ◽  
Ronald K. Hanson
Author(s):  
Sulaiman A. Alturaifi ◽  
Tatyana Atherley ◽  
Olivier Mathieu ◽  
Bing Guo ◽  
Eric L. Petersen

Abstract In recent years, there has been an interest in finding a jet fuel alternative to the crude oil-based kerosene. Gas-to-liquid (GtL) fuel is being derived via Fischer-Tropsch synthesis processes by converting natural gas to longer-chain hydrocarbons which form the basis for jet fuel. In this study, new experimental ignition delay time measurements of GtL jet fuels have been determined at elevated pressures and temperatures. The measurements were conducted in a heated, high-pressure shock-tube facility capable of initial temperatures up to 200°C. Two GtL jet fuels were investigated, Shell GTL and Syntroleum S-8, which can be used in aviation applications at concentrations up to 50% blended with conventional oil-based kerosene. The ignition delay time measurements were conducted behind reflected shock waves for gaseous-phase fuel in air at a pressure around 10 atm and over a temperature range of 966 to 1266 K for two equivalence ratios, fuel lean (ϕ = 0.5) and stoichiometric (ϕ = 1.0). Ignition delay time was determined by observing the pressure and electronically excited OH chemiluminescence around 307 nm at the endwall location. Similar ignition delay times were observed for the two fuels at the fuel lean condition, while Syntroleum S-8 showed shorter ignition delay times at the stoichiometric condition. Comparisons are made with ignition delay time measurements for Jet-A previously conducted in the same facility and showed reasonable agreement over the tested conditions. The predictions from the available literature for GtL fuel surrogate kinetics models were obtained and compared with the experimental measurements.


Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
I. V. Sorokin ◽  
E. A. Selikhova ◽  
...  

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.


Author(s):  
Haoqiang Sheng ◽  
Xiaobin Huang ◽  
Zhijia Chen ◽  
Zhengchuang Zhao ◽  
Hong Liu

2021 ◽  
Vol 230 ◽  
pp. 111426
Author(s):  
Saja Almohammadi ◽  
Mireille Hantouche ◽  
Olivier P. Le Maître ◽  
Omar M. Knio

2021 ◽  
Vol 223 ◽  
pp. 98-109
Author(s):  
Khaiyom Hakimov ◽  
Farhan Arafin ◽  
Khalid Aljohani ◽  
Khalil Djebbi ◽  
Erik Ninnemann ◽  
...  

2013 ◽  
Vol 699 ◽  
pp. 111-118
Author(s):  
Rui Shi ◽  
Chang Hui Wang ◽  
Yan Nan Chang

Based on GRI3.0, we study the main chemical kinetics process about reactions of singlet oxygen O2(a1Δg) and ozone O3 with methane-air combustion products, inherit and further develop research in chemical kinetics process with enhancement effects on methane-air mixed combustion by these two molecules. In addition, influence of these two molecules on ignition delay time and flame speed of laminar mixture are considered in our numerical simulation research. This study validates the calculation of this model which cotains these two active molecules by using experimental data of ignition delay time and the speed of laminar flame propagation. In CH4-air mixing laminar combustion under fuel-lean condition(ф=0.5), flame speed will be increased, and singlet oxygen with 10% of mole fraction increases it by 80.34%, while ozone with 10% mole fraction increase it by 127.96%. It mainly because active atoms and groups(O, H, OH, CH3, CH2O, CH3O, etc) will be increased a lot after adding active molecules in the initial stage, and chain reaction be reacted greatly, inducing shortening of reaction time and accelerating of flame speed. Under fuel rich(ф=1.5), accelerating of flame speed will be weakened slightly, singlet oxygen with 10% in molecular oxygen increase it by 48.93%, while ozone with 10% increase it by 70.25%.


Author(s):  
P. Gokulakrishnan ◽  
M. S. Klassen ◽  
R. J. Roby

Ignition delay times of a “real” synthetic jet fuel (S8) were measured using an atmospheric pressure flow reactor facility. Experiments were performed between 900 K and 1200 K at equivalence ratios from 0.5 to 1.5. Ignition delay time measurements were also performed with JP8 fuel for comparison. Liquid fuel was prevaporized to gaseous form in a preheated nitrogen environment before mixing with air in the premixing section, located at the entrance to the test section of the flow reactor. The experimental data show shorter ignition delay times for S8 fuel than for JP8 due to the absence of aromatic components in S8 fuel. However, the ignition delay time measurements indicate higher overall activation energy for S8 fuel than for JP8. A detailed surrogate kinetic model for S8 was developed by validating against the ignition delay times obtained in the present work. The chemical composition of S8 used in the experiments consisted of 99.7 vol% paraffins of which approximately 80 vol% was iso-paraffins and 20% n-paraffins. The detailed kinetic mechanism developed in the current work included n-decane and iso-octane as the surrogate components to model ignition characteristics of synthetic jet fuels. The detailed surrogate kinetic model has approximately 700 species and 2000 reactions. This kinetic mechanism represents a five-component surrogate mixture to model generic kerosene-type jets fuels, namely, n-decane (for n-paraffins), iso-octane (for iso-paraffins), n-propylcyclohexane (for naphthenes), n-propylbenzene (for aromatics) and decene (for olefins). The sensitivity of iso-paraffins on jet fuel ignition delay times was investigated using the detailed kinetic model. The amount of iso-paraffins present in the jet fuel has little effect on the ignition delay times in the high temperature oxidation regime. However, the presence of iso-paraffins in synthetic jet fuels can increase the ignition delay times by two orders of magnitude in the negative temperature (NTC) region between 700 K and 900 K, typical gas turbine conditions. This feature can have a favorable impact on preventing flashback caused by the premature autoignition of liquid fuels in lean premixed prevaporized (LPP) combustion systems.


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