An Ignition Delay Study of Category A and C Aviation Fuel

2015 ◽  
Author(s):  
Kyungwook Min ◽  
Daniel Valco ◽  
Anna Oldani ◽  
Tonghun Lee
Keyword(s):  
Ignition Delay ◽  
Cetane Number ◽  
Test Chamber ◽  
Combustion Characteristics ◽  
Aviation Fuel ◽  
Jet Fuels ◽  
Fuel Blend ◽  
Auto Ignition ◽  
Alternative Aviation Fuels ◽  
Pressure Trace

Ignition delay of category A and C alternative aviation fuels have been investigated using a rapid compression machine (RCM). Newly introduced alternative jet fuels are not yet comprehensively understood in their combustion characteristics. Two of the category C fuels that will be primarily investigated in this study are Amyris Farnesane and Gevo Jet Fuel Blend. Amyris direct sugar to hydrocarbon (DSHC) fuel (POSF 10370) come from direct fermentation of bio feedstock sugar. Amyris DSHC is mainly composed of 2,6,10-trymethly dodecane, or farnesane. Gevo jet blend stock fuel is alcohol to jet (ATJ) fuel (POSF 10262) produced from bio derived butanol. Gevo jet blend stock is composed with iso-dodecane and iso-cetane, and has significantly low derived cetane number of 15. The experimental results are compared to combustion characteristics of conventional jet A fuels, including JP-8. Ignition delay, the important factor of auto ignition characteristic, is evaluated from pressure trace measured from the RCM at University of Illinois, Urbana-Champaign. The measurements are made at compressed pressure 20bar, intermediate and low compressed temperature, and equivalence ratio of unity and below. Direct test chamber charge method is used due to its reliable reproducibility of results. Compared to category A fuels, different combustion characteristics has been observed from category C fuels due to their irregular chemical composition.

Effects of branch structure of alkylbenzenes on spray auto-ignition of n-decane and alkylbenzenes blends

2020 ◽  
pp. 146808742091471 ◽  
Author(s):  
Yaozong Duan ◽  
Wang Liu ◽  
Xin Liang ◽  
Dong Han
Keyword(s):  
Ignition Delay ◽  
Cetane Number ◽  
Methyl Groups ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Combustion Duration ◽  
Ignition Characteristics ◽  
Ignition Propensity

Spray auto-ignition characteristics of the blends of n-decane and several alkylbenzenes were carried out on a heated constant-volume spray combustion chamber. The derived cetane numbers of the fuel blends were determined, and the temperature-dependent ignition delay times and combustion durations were measured across a range of temperatures from 808 to 911 K. The results reveal that blending alkylbenzene to n-decane inhibits fuel spray auto-ignition propensity. For mono-alkylbenzenes, the fuel blend containing toluene has a higher derived cetane number than those with ethylbenzene and n-propylbenzene, but has a lower derived cetane number than the fuel blend containing n-butylbenzene. For those binary fuels containing ethylbenzene, n-propylbenzene and n-butylbenzene, their derived cetane numbers increase with the side alkyl chain length. The derived cetane numbers of the fuel blends with C8H10 isomers follow the trend of n-decane/ o-xylene >  n-decane/ethylbenzene >  n-decane/ m-xylene ∼ n-decane/ p-xylene, given the alkylbenzene blending fraction. For the blends with C9H12 isomers, those containing 1,2,3-trimethylbenzene and 1,3,5-trimethylbenzene have the highest and lowest derived cetane numbers, respectively, while the fuel blends containing 1,2,4-trimethylbenzene, n-propylbenzene and i-propylbenzene have comparatively intermediate derived cetane numbers. The blending effects of alkylbenzenes on ignition delay time are consistent with the observation on fuel derived cetane numbers. Both the number and proximity of substituted methyl groups significantly affect fuel auto-ignition propensity, and the adjacent methyl groups could increase the auto-ignition propensity. The combustion duration for the test fuels, except for n-decane and the n-decane/ n-butylbenzene blend, monotonically decreases with increased temperature. The non-monotonic dependence of combustion duration on temperature, for neat n-decane and the n-decane/ n-butylbenzene blend, may result from the increased diffusive burnt fraction. Finally, the comparison between gas-phase and spray auto-ignition reactivity of the test fuels highlights the contribution of both fuel physics and chemistry in spray auto-ignition.

Relation between Cetane Number and the Ignition Delay of Jet Fuels

2022 ◽  
Author(s):  
Paxton W. Wiersema ◽  
Keunsoo Kim ◽  
Tonghun Lee ◽  
Eric Mayhew ◽  
Jacob Temme ◽  
...  
Keyword(s):  
Ignition Delay ◽  
Cetane Number ◽  
Jet Fuels

scholarly journals Influence of Combustion Characteristics and Fuel Composition on Exhaust PAHs in a Compression Ignition Engine

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2575 ◽  
Author(s):  
Hamisu Adamu Dandajeh ◽  
Midhat Talibi ◽  
Nicos Ladommatos ◽  
Paul Hellier
Keyword(s):  
Environmental Protection Agency ◽  
Ignition Delay ◽  
Combustion Characteristics ◽  
Exhaust Emission ◽  
Fuel Composition ◽  
Particulate Phase ◽  
Compression Ignition Engine ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Methyl Decanoate

This paper reports an experimental investigation into the effects of fuel composition on the exhaust emission of toxic polycyclic aromatic hydrocarbons (PAHs) from a diesel engine, operated at both constant fuel injection and constant fuel ignition modes. The paper quantifies the US EPA (United State Environmental Protection Agency) 16 priority PAHs produced from combustion of fossil diesel fuel and several model fuel blends of n-heptane, toluene and methyl decanoate in a single-cylinder diesel research engine based on a commercial light duty automotive engine. It was found that the level of total PAHs emitted by the various fuel blends decreased with increasing fuel ignition delay and premixed burn fraction, however, where the ignition delay of a fuel blend was decreased with use of an ignition improving additive the level of particulate phase PAH also decreased. Increasing the level of toluene present in the fuel blends decreased levels of low toxicity of two to four ring PAH, while displacing n-heptane with methyl decanoate increased particulate phase adsorbed PAH. Overall, the composition of the fuels investigated was found to have more influence on the concentration of exhaust PAHs formed than that of combustion characteristics, including ignition delay, peak heat release rate and the extent of the premixed burn fractions.

ERRATUM: Derived Cetane Number, Distillation and Ignition Delay Properties of Diesel and Jet Fuels Containing Blended Synthetic Paraffinic Mixtures

2016 ◽  
Vol 10 (1) ◽  
pp. 249-249
Author(s):  
Sylvester Abanteriba ◽  
Ulas Yildirim ◽  
Renee Webster ◽  
David Evans ◽  
Paul Rawson
Keyword(s):  
Ignition Delay ◽  
Cetane Number ◽  
Jet Fuels

Development of a Numerical Model for Ignition Phenomena in a Micro Pilot Ignited Dual Fuel Engine With External Mixture Formation

2017 ◽  
Author(s):  
Michael Schiffner ◽  
Marcus Grochowina ◽  
Thomas Sattelmayer
Keyword(s):  
Flame Propagation ◽  
Ignition Delay ◽  
Cfd Simulation ◽  
Injection Pressure ◽  
Optical Measurements ◽  
Effect Of Temperature ◽  
Dual Fuel ◽  
Ignition Process ◽  
Fuel Blend ◽  
Auto Ignition

In this paper, a numerical investigation of the ignition process of dual fuel engines is presented. Optical measurements revealed that a homogeneous natural gas charge ignited by a small diesel pilot comprises the combustion phenomena of compression ignition of the pilot fuel as well as premixed flame propagation. The 3-Zones Extended Coherent Flame Model (ECFM3Z) was selected, since it can treat auto-ignition, pre-mixed flame propagation and diffusion flame aspects. Usually combustion models in multi-dimensional computational fluid dynamics (CFD) software packages are designed to handle only one reactive species representing the fuel concentration. In the context of the ECFM3Z model the concept of a multi-component fuel is applied to dual fuel operation. Since the available ignition models were not able to accurately describe the ignition characteristics of the investigated setup, a new dual fuel auto-ignition model was developed. Ignition delay times of the fuel blend are tabulated using a detailed reaction mechanism for n-heptane. Thereby, the local progress of pre-ignition reactions in the CFD simulation can be calculated. The ignition model is validated against experiments conducted with a periodically chargeable constant volume combustion chamber. The proposed model is capable to reproduce the ignition delay as well as the location of the flame kernels. The CFD simulations show the effect of temperature stratification and variations in the injection pressure on the apparent ignition delay of the micro pilot.

Gas-to-Liquid Sprays at Different Injection and Ambient Conditions

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Dung Ngoc Nguyen ◽  
Hiroaki Ishida ◽  
Masahiro Shioji
Keyword(s):  
Oxygen Concentration ◽  
Ignition Delay ◽  
Alternative Fuels ◽  
Ambient Pressure ◽  
Cetane Number ◽  
Combustion Characteristics ◽  
Gas Oil ◽  
Ambient Conditions ◽  
Ignition Quality ◽  
Gas To Liquid

Alternative fuels exhibit potential as a clean fuel and suitable to address problems of energy security and environmental pollution. The main objective of this research was to provide the fundamental data of ignition delay and combustion characteristics for gas-to-liquid (GTL) fuels. Experiments were carried out in a constant-volume vessel under diesel-engine conditions to study the effects of various injection and ambient conditions on ignition and combustion characteristics. The results showed that all tested fuels exhibited similar ignition-delay trends: Ignition delay increased as ambient temperature, ambient pressure, and oxygen concentration decreased. The result of changing injection pressures and nozzle-hole diameters did not significantly affect ignition-delay values for all tested fuels. The variation in ignition-delay values was small at temperatures higher than 700 K but large at temperatures less than 700 K. In addition, the result showed that GTL fuels with high cetane number corresponded to shorter ignition delay and smoother heat-release rate than those for gas-oil (conventional diesel fuel) at the same temperature, pressure, and oxygen concentration. The blend GTL fuel improved ignition quality and combustion than that of gas-oil. Shadowgraph images showed that GTL fuels exhibited shorter spray penetration and mixed with the hot air quicker than gas-oil. In addition, GTL fuels showed suitability for premixed charge compression-ignition operations owing to ignitability at low temperature. The obtained results provide useful information for finding the optimal conditions for the design and control of diesel engines fuelled by synthetic GTL fuels.

Characteristics of Deposits in Gas Turbine Combustion Chambers Using Synthetic and Conventional Jet Fuels

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Greg Pucher ◽  
William Allan ◽  
Pierre Poitras
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Alternative Fuels ◽  
Large Scale ◽  
Aviation Fuel ◽  
Jet Fuels ◽  
Combustion Chambers ◽  
Fuel Blend ◽  
Synthetic Fuel ◽  
Camelina Oil

The synthetic fuel industry is poised to experience large-scale growth and profoundly affect current aviation fuel infrastructure. New candidate technologies, such as Camelina oil-derived synthetic fuel have been demonstrated to not only provide satisfactory quasi drop-in characteristics for conventional fuels, but in life cycle analysis studies have also been shown to potentially offer positive improvements relative to conventional feedstocks with respect to economic, environmental, and land use considerations. As part of a multiyear study at the Royal Military College of Canada to evaluate combustion related parameters of fuel additives and alternative fuels for gas turbine applications, a Camelina-derived synthetic fuel blend was assessed to determine potential combustion related benefits as compared to conventional and other synthetic blends. The Combustion Chamber Sector Rig (CCSR) which houses a Rolls Royce T-56-A-15 combustion section was utilized for the evaluation of emissions and deposits. Following combustion testing, several combustion system components, including the combustion chamber, fuel nozzle, and igniter plug were analyzed for relative levels of deposit build-up. As with other Fischer Tropsch derived synthetic fuels, there were positive benefits found with Camelina blends in terms of emissions performance and deposit production tendencies.

Investigation on the spray development, the combustion characteristics and the emissions of Fischer–Tropsch fuel and diesel fuel from direct coal liquefaction

2017 ◽  
Vol 231 (13) ◽  
pp. 1829-1837 ◽  
Author(s):  
Yiqiang Pei ◽  
Jing Qin ◽  
Yuli Dai ◽  
Kun Wang
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Cetane Number ◽  
Combustion Process ◽  
Physicochemical Characteristics ◽  
Combustion Characteristics ◽  
Coal Liquefaction ◽  
Fischer Tropsch ◽  
Planar Laser ◽  
Direct Coal Liquefaction

Diesel fuel is largely consumed by transportation services, and diesel fuel from direct coal liquefaction and Fischer–Tropsch fuel have been produced as alternatives in coal-rich areas. However, the physicochemical characteristics of the two fuels are not quite the same as those of diesel fuel derived from crude oil. Therefore, the spray development, the combustion characteristics and the emissions of diesel fuel from direct coal liquefaction, Fischer–Tropsch fuel and commercial diesel fuel were studied in this paper. The spray development was investigated by using planar laser-induced fluorescence, and the results showed that the spray characteristics of coal-liquefied fuel were similar to those of commercial diesel fuel. Diesel fuel from direct coal liquefaction has a longer ignition delay and a higher heat release rate from premixed combustion than commercial diesel fuel does because of its lower cetane number at low loads. However, the same combustion characteristics with commercial diesel fuel can be achieved by mixing diesel fuel from direct coal liquefaction and Fischer–Tropsch fuel in a ratio of 3 to 1. With increasing engine load, the in-cylinder temperature and the pressure increased which reduced the effect of the cetane number on the ignition delay and the combustion process. The regulated emissions from Fischer–Tropsch fuel were the lowest of these fuels; the unregulated emissions measured by Fourier transform infrared spectroscopy, however, were slightly higher than those of the other two fuels.

Effect of Inlet Air Temperature on Auto-Ignition of Fuels With Different Cetane Number and Volatility

2011 ◽  
Author(s):  
Chandrasekharan Jayakumar ◽  
Ziliang Zheng ◽  
Umashankar M. Joshi ◽  
Walter Bryzik ◽  
Naeim A. Henein ◽  
...  
Keyword(s):  
Air Temperature ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Cetane Number ◽  
Delay Period ◽  
Inlet Temperature ◽  
Ignition Process ◽  
Ultra Low Sulfur Diesel ◽  
Auto Ignition ◽  
Ignition Delay Period

This paper investigates the effect of air inlet temperature on the auto-ignition of fuels that have different CN and volatility in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 44.1 & 31) and F-T SPK. Detailed analysis is made of the rate of heat release during the ignition delay period, to determine the effect of fuel volatility and CN on the auto-ignition process. A STAR-CD CFD model is applied to simulate the spray behavior and gain more insight into the processes that immediately follow the fuel injection including evaporation, start of exothermic reactions and the early stages of combustion. The mole fractions of different species are determined during the ignition delay period and their contribution in the auto-ignition process is examined. Arrhenius plots are developed to calculate the global activation energy for the auto-ignition reactions of these fuels. Correlations are developed for the ID and the mean air temperature and pressure.

Diethyl Ether as an Ignition Enhancer for Naphtha Creating a Drop in Fuel for Diesel

2016 ◽  
Author(s):  
R. Vallinayagam ◽  
S. Vedharaj ◽  
S. Mani Sarathy ◽  
Robert W. Dibble
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ignition Delay ◽  
Cetane Number ◽  
Cylinder Pressure ◽  
Auto Ignition ◽  
Peak Heat Release Rate ◽  
Ignition Characteristics ◽  
Ci Engines

Direct use of naphtha in compression ignition (CI) engines is not advisable because its lower cetane number negatively impacts the auto ignition process. However, engine or fuel modifications can be made to operate naphtha in CI engines. Enhancing a fuel’s auto ignition characteristics presents an opportunity to use low cetane fuel, naphtha, in CI engines. In this research, Di-ethyl ether (DEE) derived from ethanol is used as an ignition enhancer for light naphtha. With this fuel modification, a “drop-in” fuel that is interchangeable with existing diesel fuel has been created. The ignition characteristics of DEE blended naphtha were studied in an ignition quality tester (IQT); the measured ignition delay time (IDT) for pure naphtha was 6.9 ms. When DEE was added to naphtha, IDT decreased and D30 (30% DEE + 70% naphtha) showed comparable IDT with US NO.2 diesel. The derived cetane number (DCN) of naphtha, D10 (10% DEE + 90% naphtha), D20% DEE + 80% naphtha) and D30 were measured to be 31, 37, 40 and 49, respectively. The addition of 30% DEE in naphtha achieved a DCN equivalent to US NO.2 diesel. Subsequent experiments in a CI engine exhibited longer ignition delay for naphtha compared to diesel. The peak in-cylinder pressure is higher for naphtha than diesel and other tested fuels. When DEE was added to naphtha, the ignition delay shortened and peak in-cylinder pressure is reduced. A 3.7% increase in peak in-cylinder pressure was observed for naphtha compared to US NO.2 diesel, while D30 showed comparable results with diesel. The pressure rise rate dropped with the addition of DEE to naphtha, thereby reducing the ringing intensity. Naphtha exhibited a peak heat release rate of 280 kJ/m3deg, while D30 showed a comparable peak heat release rate to US NO.2 diesel. The amount of energy released during the premixed combustion phase decreased with the increase of DEE in naphtha. Thus, this study demonstrates the suitability of DEE blended naphtha mixtures as a “drop-in” replacement fuel for diesel.

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