Experimental investigation of the effect of temperature on ignition of modified kerosene

2021 ◽  
pp. 146808742098819
Author(s):  
Aldin Justin Sundararaj ◽  
K R Guna ◽  
Matthew William
Keyword(s):  
Surface Tension ◽  
Gas Phase ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Pressure Range ◽  
Ignition Delay Time ◽  
Light Emission ◽  
Pressure Rise ◽  
Effect Of Temperature ◽  
Pressure Transducers

Kerosene based hydrocarbon fuels are preferred candidates for the source of energy due to its stable properties. Based on the requirement of the combustor and the growing concern over pollutant, kerosene based fuels are modified. The fuel under investigation is a modified form of kerosene with ultra-low sulphur content. The effect of temperature on modified kerosene is studied for viscosity, surface tension, specific heat, density and ignition delay. The time delay for ignition of gas-phase mixtures of modified kerosene/oxygen have been measured using a shock tube facility. The experiments are conducted in the temperature range of 1200–1877 K, pressure range of 4–12 atm and equivalence ratio of Ø = 1.5, 1 and 0.5. The ignition delay time measurements were carried out using piezoelectric pressure transducers, which records the pressure rise due to ignition and simultaneously recording the light emission during the process of ignition using a photodiode. The ignition delay is represented as τign = 0.168841 × P−1.49 × Ø0.72 × e(14310/T)

scholarly journals Numerical Simulations and Experiments of Ignition of Solid Particles in a Laminar Burner: Effects of Slip Velocity and Particle Swelling

2020 ◽  
Author(s):  
Antonio Attili ◽  
Pooria Farmand ◽  
Christoph Schumann ◽  
Sima Farazi ◽  
Benjamin Böhm ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ignition Delay ◽  
Delay Time ◽  
Slip Velocity ◽  
Ignition Delay Time ◽  
Flame Structure ◽  
Particle Diameter ◽  
Point Particle ◽  
Solid Particles ◽  
Experimental Measurements

Abstract Ignition and combustion of pulverized solid fuel is investigated in a laminar burner. The two-dimensional OH radical field is measured in the experiments, providing information on the first onset of ignition and a detailed characterization of the flame structure for the single particle. In addition, particle velocity and diameter are tracked in time in the experiments. Simulations are carried out with a Lagrangian point-particle approach fully coupled with an Eulerian solver for the gas-phase, which includes detailed chemistry and transport. The numerical simulation results are compared with the experimental measurements in order to investigate the ignition characteristics. The effect of the slip velocity, i.e. the initial velocity difference between the gas-phase and the particle, is investigated numerically. For increasing slip velocity, the ignition delay time decreases. For large slip velocities, the decrease in ignition delay time is found to saturate to a value which is about 40% smaller than the ignition delay time at zero slip velocity. Performing a simulation neglecting the dependency of the Nusselt number on the slip velocity, it is found that this dependency does not play a role. On the contrary, it is found that the decrease of ignition delay time induced by the slip velocity is due to modifications of the temperature field around the particle. In particular, the low-temperature fluid related to the energy sink due to particle heating is transported away from the particle position when the slip velocity is non-zero; therefore, the particle is exposed to larger temperatures. Finally, the effect of particle swell is investigated using a model for the particle swelling based on the CPD framework. With this model, we observed negligible differences in ignition delay time compared to the case in which swelling is not included. This is related to the negligible swelling predicted by this model before ignition. However, this is inconsistent with the experimental measurements of particle diameter, showing a significant increase of diameter even before ignition. In further simulations, the measured swelling was directly prescribed, using an analytical fit at the given conditions. With this approach, it is found that the inclusion of swelling reduces the ignition delay time by about 20% for small particles while it is negligible for large particles.

scholarly journals Numerical Investigation of Combustion Characteristics of a Wave Rotor Combustor Based on a Reduced Reaction Mechanism of Ethylene

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Jianzhong Li ◽  
Li Yuan ◽  
Wei Li ◽  
Kaichen Zhang
Keyword(s):  
Reaction Mechanism ◽  
Flame Propagation ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Wave Rotor ◽  
Elementary Reactions ◽  
Coupling Time

To improve simulations of the flame and pressure wave propagation process and investigate the combustion characteristics of a wave rotor combustor (WRC), direct relation graphs with error propagation (DRGEP), quasi-steady-state assumption (QSSA), and sensitivity analysis were used to establish a reduced reaction mechanism comprised of 23 species and 55 elementary reactions, based on the LLNL N-Butane mechanism. The reduced reaction mechanism of ethylene was combined with an eddy dissipation concept (EDC) model to simulate the flame propagation characteristics in a simplified WRC channel. The effects of spoilers with different blockage ratios and hot-jets of different species on combustion characteristics of flame propagation and pressure rise in the WRC channel were investigated. When the heated inert air was used as hot-jet, the ignition delay time of WRC would increase, which indicated that the activity of the burned gas from the hot-jet igniter would affect the ignition delay time. The spoiler facilitates the coupling of flame and shock waves to reduce the coupling time and distance. With the blockage ratio of the spoiler increasing, the coupling time and distance would be reduced.

Experimental and Kinetic Modeling of Kerosene-Type Fuels at Gas Turbine Operating Conditions

2006 ◽  
Vol 129 (3) ◽  
pp. 655-663 ◽  
Author(s):  
P. Gokulakrishnan ◽  
G. Gaines ◽  
J. Currano ◽  
M. S. Klassen ◽  
R. J. Roby
Keyword(s):  
Low Temperature ◽  
Gas Turbine ◽  
Ignition Delay ◽  
Delay Time ◽  
Equivalence Ratio ◽  
Ignition Delay Time ◽  
Flow Reactor ◽  
Fuel Oil ◽  
Stirred Reactor ◽  
Lean Conditions

Experimental and kinetic modeling of kerosene-type fuels is reported in the present work with special emphasis on the low-temperature oxidation phenomenon relevant to gas turbine premixing conditions. Experiments were performed in an atmospheric pressure, tubular flow reactor to measure ignition delay time of kerosene (fuel–oil No. 1) in order to study the premature autoignition of liquid fuels at gas turbine premixing conditions. The experimental results indicate that the ignition delay time decreases exponentially with the equivalence ratio at fuel-lean conditions. However, for very high equivalence ratios (>2), the ignition delay time approaches an asymptotic value. Equivalence ratio fluctuations in the premixer can create conditions conducive for autoignition of fuel in the premixer, as the gas turbines generally operate under lean conditions during premixed prevaporized combustion. Ignition delay time measurements of stoichiometric fuel–oil No. 1∕air mixture at 1 atm were comparable with that of kerosene type Jet-A fuel available in the literature. A detailed kerosene mechanism with approximately 1400 reactions of 550 species is developed using a surrogate mixture of n-decane, n-propylcyclohexane, n-propylbenzene, and decene to represent the major chemical constituents of kerosene, namely n-alkanes, cyclo-alkanes, aromatics, and olefins, respectively. As the major portion of kerosene-type fuels consists of alkanes, which are relatively more reactive at low temperatures, a detailed kinetic mechanism is developed for n-decane oxidation including low temperature reaction kinetics. With the objective of achieving a more comprehensive kinetic model for n-decane, the mechanism is validated against target data for a wide range of experimental conditions available in the literature. The data include shock tube ignition delay time measurements, jet-stirred reactor reactivity profiles, and plug-flow reactor species time–history profiles. The kerosene model predictions agree fairly well with the ignition delay time measurements obtained in the present work as well as the data available in the literature for Jet A. The kerosene model was able to reproduce the low-temperature preignition reactivity profile of JP-8 obtained in a flow reactor at 12 atm. Also, the kerosene mechanism predicts the species reactivity profiles of Jet A-1 obtained in a jet-stirred reactor fairly well.

Ignition and Oxidation of 50/50 Butane Isomer Blends

2009 ◽  
Author(s):  
Nicole Donato ◽  
Christopher Aul ◽  
Eric Petersen ◽  
Christopher Zinner ◽  
Henry Curran ◽  
...  
Keyword(s):  
Shock Tube ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Ignition Time ◽  
Pressure Rise ◽  
Time Data ◽  
Kinetics Modeling ◽  
Time Sensitivity ◽  
Wide Range

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.

Understanding the Effect of Oxygenated Biofuels Addition on Combustion Characteristics of Gasoline

2018 ◽  
Author(s):  
Shrabanti Roy ◽  
Saeid Zare ◽  
Omid Askari
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Equivalence Ratio ◽  
Ignition Delay Time ◽  
Combustion Characteristics ◽  
Wide Range ◽  
Oxygenated Fuels ◽  
Laminar Burning Speed

The change in laminar burning speed and ignition delay time of iso-octane with the addition of oxygenated fuels are investigated. As oxygenated fuels, ethanol and 2,5 dimethyle furan (DMF) are used. To confirm the process and mechanism a detailed validation is done on laminar burning speed and ignition delay time. Further, three different blending ratios of 5%, 25% and 50% for both ethanol/iso-octane and DMF/iso-octane are investigated separately. Wide range of equivalence ratio from 0.6–1.4 is considered in calculating laminar burning speed. Ignition delay time is measured under various temperatures from 650 K to 1100 K. Results of each blending are compared with the pure fuels. A comparison is also done between the effects of these two oxygenates. It has found that for each blending case presence of DMF brings larger change in the behavior of iso-octane than ethanol. This observation refers to further study on comparison of these two oxygenates.

The Effect of Multi-Component Fuel Evaporation on the Ignition of JP-8

2010 ◽  
Author(s):  
R. Joklik ◽  
C. Fuller ◽  
B. Turner ◽  
P. Gokulakrishnan
Keyword(s):  
Gas Phase ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Chemical Kinetic ◽  
Component Model ◽  
Fuel Composition ◽  
Discrete Component ◽  
Kinetic Mechanisms ◽  
Fuel Evaporation

In this work distillation curve (DC) and probability distribution function (PDF) models of multi-component droplet evaporation were investigated in order to determine the feasibility of recovering information about the gas-phase composition from a minimal number of variables associated with the droplet. Both models were assessed against a discrete component model based on the classic B-number formulation using a 63 component model of JP-8. The results indicate that, although the gas-phase fuel composition may undergo large changes during the droplet lifetime, it is possible to recover composition information in terms of the major classes of species present with reasonable accuracy (+/− 5%) using the DC and PDF models. The potential impact of variation in gas-phase fuel composition was investigated by performing ignition delay time (IDT) calculations using two detailed chemical kinetic mechanisms for JP-8. The results indicate that, especially in the low temperature region (700 K – 900 K), variation in gas-phase fuel composition can have a large impact on the ignition delay time. Experimental IDT measurements at 900 and 950 K showed a larger variation in IDT due to composition than that predicted by the models.

Investigation on the Ignition Conditions From a Comparison Between Reacting and Non-Reacting Diesel Spray Experiments

2002 ◽  
Author(s):  
T. Kim ◽  
J. B. Ghandhi
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
High Speed ◽  
Equivalence Ratio ◽  
Ignition Delay Time ◽  
Ignition Time ◽  
Liquid Core ◽  
Injection Pressure ◽  
Lift Off ◽  
Injection Pressures

Natural luminosity images from reacting diesel sprays were acquired in a combustion-type constant-volume spray chamber. Using an ambient condition of 15 kg/m3 and 1000 K, the effects of peak injection pressures (60, 90 and 150 MPa) and nozzle hole sizes (140, 158 and 200 μm) were investigated. From high-speed natural luminosity cinematography, macroscopic reacting spray characteristics such as flame lift-off height and ignition delay time were obtained. For increasing injection pressures the ignition delay time decreased, and the flame lift off height increased. For increasing hole diameter the ignition time delay decreased, and the flame lift-off height decreased. The authors’ previous results of the fuel concentration measurement from non-reacting spray experiments were used to ascertain the local equivalence ratio for the reacting spray during the ignition and initial flame development period. The first detection of the luminosity (believed to be chemiluminescence) signal was found to occur in fuel-rich vapor regions near the boundary of the liquid core with an equivalence ratio near 2 and a temperature of approximately 800 K. These conditions were found to be independent of injection pressure and nozzle diameter for the condition tested (15 kg/m3 and 1000 K ambient), suggesting that this is a kinetically controlled process.

scholarly journals Towards quantitative prediction of ignition-delay-time sensitivity on fuel-to-air equivalence ratio

2020 ◽  
Vol 214 ◽  
pp. 103-115 ◽  
Author(s):  
Richard A. Messerly ◽  
Mohammad J. Rahimi ◽  
Peter C. St. John ◽  
Jon H. Luecke ◽  
Ji-Woong Park ◽  
...  
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Equivalence Ratio ◽  
Ignition Delay Time ◽  
Quantitative Prediction ◽  
Time Sensitivity
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