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.

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.

A Numerical Study on the Low Limit Auto-Ignition Temperature of Syngas and Modification of Chemical Kinetic Mechanism

2019 ◽  
Author(s):  
Seung Eon Jang ◽  
Jin Park ◽  
Sang Hyeon Han ◽  
Hong Jip Kim ◽  
Ki Sung Jung ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Region ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Numerical Results ◽  
Auto Ignition ◽  
Chemical Kinetic Mechanism

Abstract In this study, the auto ignition with low limit temperature of syngas has been numerically investigated using a 2-D numerical analysis. Previous study showed that auto ignition was observed at above 860 K in co-flow jet experiments using syngas and dry air. However, the auto ignition at this low temperature range could not be predicted with existing chemical mechanisms. Inconsistency of the auto ignition temperature between the experimental and numerical results is thought to be due to the inaccuracy of the chemical kinetic mechanism. The prediction of ignition delay time and sensitivity analysis for each chemical kinetic mechanism were performed to verify the reasons of the inconsistency between the experimental and numerical results. The results which were calculated using the various mechanisms showed significantly differences in the ignition delay time. In this study, we intend to analyze the reason of discrepancy to predict the auto ignition with low pressure and low temperature region of syngas and to improve the chemical kinetic mechanism. A sensitive analysis has been done to investigate the reaction steps which affected the ignition delay time significantly, and the reaction rate of the selected reaction step was modified. Through the modified chemical kinetic mechanism, we could identify the auto ignition in the low temperature region from the 2-D numerical results. Then CEMA (Chemical Explosive Mode Analysis) was used to validate the 2-D numerical analysis with modified chemical kinetic mechanism. From the validation, the calculated λexp, EI, and PI showed reasonable results, so we expect that the modified chemical kinetic mechanism can be used in various low temperature region.

RON and MON chemical kinetic modeling derived correlations with ignition delay time for gasoline and octane boosting additives

2020 ◽  
Vol 219 ◽  
pp. 359-372
Author(s):  
Julius A. Corrubia ◽  
Jonathan M. Capece ◽  
Nicholas P. Cernansky ◽  
David L. Miller ◽  
Russell P. Durrett ◽  
...  
Keyword(s):  
Kinetic Modeling ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Chemical Kinetic

Chemical Kinetic Model Reduction and Analysis of Tetrahydrofuran Combustion Using Stochastic Species Elimination

2020 ◽  
Author(s):  
Mazen A. Eldeeb ◽  
Malshana Wadugurunnehalage
Keyword(s):  
Kinetic Model ◽  
Model Reduction ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Laminar Flame ◽  
Chemical Kinetic ◽  
Reduced Model ◽  
Chemical Kinetic Model ◽  
Parameter Modification

Abstract In this work, a chemical kinetic modeling study of the high-temperature ignition and laminar flame behavior of Tetrahydrofuran (THF), a promising second-generation transportation biofuel, is presented. Stochastic Species Elimination (SSE) model reduction approach (Eldeeb and Akih-Kumgeh, Proceedings of ASME Power Conference 2018) is implemented to develop multiple skeletal versions of a detailed chemical kinetic model of THF (Fenard et al., Combustion and Flame, 2018) based on ignition delay time simulations at various pressures and temperature ranges. The detailed THF model contains 467 species and 2390 reactions. The developed skeletal versions are combined into an overall reduced model of THF, consisting of 193 species and 1151 reactions. Ignition delay time simulations are performed using detailed and reduced models, with varying levels of agreement observed at most conditions. Sensitivity analysis is then performed to identify the most important reactions responsible for the observed performance of the reduced model. Reaction rate parameter modification is performed for such reactions in order to improve the agreement of detailed and reduced model predictions with literature experimental ignition data. The work contributes toward improved understanding and modeling of the oxidation kinetics of potential transportation biofuels, especially cyclic ethers.

Ignition Delay Times of High Pressure Oxy-Methane Combustion With High Levels of CO2 Dilution

2017 ◽  
Author(s):  
Owen Pryor ◽  
Batikan Koroglu ◽  
Samuel Barak ◽  
Joseph Lopez ◽  
Erik Ninnemann ◽  
...  
Keyword(s):  
Shock Tube ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Current Data ◽  
Validation Data ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Kinetic Mechanisms ◽  
Time Histories

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.

A detailed chemical kinetic modeling, ignition delay time and jet-stirred reactor study of methanol oxidation

2016 ◽  
Vol 165 ◽  
pp. 125-136 ◽  
Author(s):  
Ultan Burke ◽  
Wayne K. Metcalfe ◽  
Sinead M. Burke ◽  
K. Alexander Heufer ◽  
Philippe Dagaut ◽  
...  
Keyword(s):  
Methanol Oxidation ◽  
Kinetic Modeling ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Chemical Kinetic ◽  
Stirred Reactor ◽  
Detailed Chemical

scholarly journals The Impact of NOx Addition on the Ignition Behavior of N-Pentane

2021 ◽  
Author(s):  
Mark Edward Fuller ◽  
Philipp Morsch ◽  
Franklin Goldsmith ◽  
Karl Alexander Heufer
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Rapid Compression Machine ◽  
Chemical Kinetic Mechanism ◽  
Rapid Compression ◽  
The Impact

This article details new ignition delay time experiments carried out on blends of n-pentane and either NO or NO<sub>2</sub> in the rapid compression machine facility at RWTH Aachen University. Further, a new chemical kinetic mechanism is developed which is able to well-reproduce the experiments and significantly improve over recently published mechanisms. <br>This work has particular value for publication as it adopts a systematic, class-based approach to mechanism development for interactions with nitrogenated species. <br>

scholarly journals The Impact of NOx Addition on the Ignition Behavior of N-Pentane

2021 ◽  
Author(s):  
Mark Edward Fuller ◽  
Philipp Morsch ◽  
Franklin Goldsmith ◽  
Karl Alexander Heufer
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Rapid Compression Machine ◽  
Chemical Kinetic Mechanism ◽  
Rapid Compression ◽  
The Impact

This article details new ignition delay time experiments carried out on blends of n-pentane and either NO or NO<sub>2</sub> in the rapid compression machine facility at RWTH Aachen University. Further, a new chemical kinetic mechanism is developed which is able to well-reproduce the experiments and significantly improve over recently published mechanisms. <br>This work has particular value for publication as it adopts a systematic, class-based approach to mechanism development for interactions with nitrogenated species. <br>

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