Validated F-T Fuel Surrogate Model for Simulation of Jet-Engine Combustion

2010 ◽  
Author(s):  
Chitralkumar V. Naik ◽  
Karthik V. Puduppakkam ◽  
Abhijit Modak ◽  
Cheng Wang ◽  
Ellen Meeks
Keyword(s):  
Laminar Flame ◽  
Laboratory Data ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Reduction Techniques ◽  
Auto Ignition ◽  
Wide Range ◽  
Fuel Behavior ◽  
Detailed Kinetics ◽  
Surrogate Fuel

Validated surrogate models have been developed for two Fisher-Tropsch (F-T) fuels. The models started with a systematic approach to determine an appropriate surrogate fuel composition specifically tailored for the two alternative jet-fuel samples. A detailed chemical kinetic mechanism has been assembled for these model surrogates starting from literature sources, and then improved to ensure self-consistency of the kinetics and thermodynamic data. This mechanism has been tested against fundamental laboratory data on auto-ignition times, laminar flame-speeds, extinction strain rates, and NOx emissions. Literature data used to validate the mechanism include both the individual surrogate-fuel components and actual F-T fuel samples where available. As part of the validation, simulations were performed for a wide variety of experimental configurations, as well as a wide range of temperatures and equivalence ratios for fuel/air mixtures. Comparison of predicted surrogate-fuel behavior against data on real F-T fuel behavior also show the effectiveness of the surrogate-matching approach and the accuracy of the detailed-kinetics mechanisms. The resulting validated mechanism has been also reduced through application of automated mechanism reduction techniques to provide progressively smaller mechanisms, with different degrees of accuracy, that are reasonable for use in CFD simulations employing detailed kinetics.

Reaction Model Development of Selected Aromatics as Relevant Molecules of a Kerosene Surrogate – The Importance of M-Xylene Within the Combustion of 1,3,5-Trimethylbenzene

2021 ◽  
Author(s):  
Astrid Ramirez Hernandez ◽  
Trupti Kathrotia ◽  
Torsten Methling ◽  
Marina Braun-Unkhoff ◽  
Uwe Riedel
Keyword(s):  
Atmospheric Pressure ◽  
Burning Velocity ◽  
Model Development ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Reaction Model ◽  
Pollutant Emissions ◽  
Similar Species ◽  
Ignition Delay Times ◽  
Wide Range

Abstract The development of advanced reaction models to predict pollutant emissions in aero-engine combustors usually relies on surrogate formulations of a specific jet fuel for mimicking its chemical composition. 1,3,5-trimethylbenzene is one of the suitable components to represent aromatics species in those surrogates. However, a comprehensive reaction model for 1,3,5-trimethylbenzene combustion requires a mechanism to describe the m-xylene oxidation. In this work, the development of a chemical kinetic mechanism for describing the m-xylene combustion in a wide parameter range (i.e. temperature, pressure, and fuel equivalence ratios) is presented. The m-xylene reaction submodel was developed based on existing reaction mechanisms of similar species such as toluene and reaction pathways adapted from literature. The sub-model was integrated into an existing detailed mechanism that contains the kinetics of a wide range of n-paraffins, iso-paraffins, cyclo-paraffins, and aromatics. Simulation results for m-xylene were validated against experimental data available in literature. Results show that the presented m-xylene mechanism correctly predicts ignition delay times at different pressures and temperatures as well as laminar burning velocities at atmospheric pressure and various fuel equivalence ratios. At high pressure, some deviations of the calculated laminar burning velocity and the measured values are obtained at stoichiometric to rich equivalence ratios. Additionally, the model predicts reasonably well concentration profiles of major and intermediate species at different temperatures and atmospheric pressure.

Combustion Simulation of Propane/Oxygen (With Nitrogen/Argon) Mixtures Using Rate-Controlled Constrained-Equilibrium

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Guangying Yu ◽  
Hameed Metghalchi ◽  
Omid Askari ◽  
Ziyu Wang
Keyword(s):  
Experimental Data ◽  
Energy System ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Oxygen Mixture ◽  
Free Valence ◽  
Wide Range ◽  
Constrained Equilibrium ◽  
Rate Controlled ◽  
Good Agreement

The rate-controlled constrained-equilibrium (RCCE), a model order reduction method, has been further developed to simulate the combustion of propane/oxygen mixture diluted with nitrogen or argon. The RCCE method assumes that the nonequilibrium states of a system can be described by a sequence of constrained-equilibrium states subject to a small number of constraints. The developed new RCCE approach is applied to the oxidation of propane in a constant volume, constant internal energy system over a wide range of initial temperatures and pressures. The USC-Mech II (109 species and 781 reactions, without nitrogen chemistry) is chosen as chemical kinetic mechanism for propane oxidation for both detailed kinetic model (DKM) and RCCE method. The derivation for constraints of propane/oxygen mixture starts from the eight universal constraints for carbon-fuel oxidation. The universal constraints are the elements (C, H, O), number of moles, free valence, free oxygen, fuel, and fuel radicals. The full set of constraints contains eight universal constraints and seven additional constraints. The results of RCCE method are compared with the results of DKM to verify the effectiveness of constraints and the efficiency of RCCE. The RCCE results show good agreement with DKM results under different initial temperature and pressures, and RCCE also reduces at least 60% CPU time. Further validation is made by comparing the experimental data; RCCE shows good agreement with shock tube experimental data.

Skeletal Kinetic Modeling for the Combustion of Endothermic Hydrocarbon Fuel in Hypersonic Vehicle

2021 ◽  
pp. 1-24
Author(s):  
Hui-Sheng Peng ◽  
Bei-Jing Zhong
Keyword(s):  
Surrogate Model ◽  
Laminar Flame ◽  
Combustion Process ◽  
Hydrocarbon Fuel ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Vital Role ◽  
Reacting Flow ◽  
Combustion Properties ◽  
Endothermic Hydrocarbon Fuel

Abstract Chemical kinetic mechanism plays a vital role in the deep learning of reacting flow in practical combustors, which can help obtain many details of the combustion process. In this paper, a surrogate model and a skeletal mechanism for an endothermic hydrocarbon fuel were developed for further investigations of the combustion performance in hypersonic vehicles: (1) The surrogate model consists of 81.3 mol% decalin and 18.7 mol% n-dodecane, which were determined by both the composition distributions and key properties of the target endothermic hydrocarbon fuel. (2) A skeletal kinetic mechanism only containing 56 species and 283 reactions was developed by the method of “core mechanism​ sub mechanism”. This mechanism can be conveniently applied to the simulation of practical combustors for its affordable scale. (3) Accuracies of the surrogate model and the mechanism were systematically validated by the various properties of the target fuel under pressures of 1-20atm, temperatures of 400-1250K, and equivalence ratios of 0.5-1.5. The overall errors for the ignition and combustion properties are no more than 0.4 and 0.1, respectively. (4) Laminar flame speeds of the target fuel and the surrogate model fuel were also measured for the validations. Results show that both the surrogate model and the mechanism can well predict the properties of the target fuel. The mechanism developed in this work is valuable to the further design and optimization of the propulsion systems.

Detailed kinetics of hydrogen abstraction from trans-decalin by OH radicals: the role of hindered internal rotation treatment

2020 ◽  
Vol 22 (44) ◽  
pp. 25740-25746
Author(s):  
Tam V.-T. Mai ◽  
Lam K. Huynh
Keyword(s):  
Master Equation ◽  
Hydrogen Abstraction ◽  
Kinetic Mechanism ◽  
Oh Radicals ◽  
Rate Model ◽  
Wide Range ◽  
Detailed Kinetics ◽  
Kinetics Of ◽  
Detailed Kinetic Mechanism

The detailed kinetic mechanism of the trans-decalin + OH reaction is firstly investigated for a wide range of conditions (T = 200–2000 K & P = 0.76–76000 Torr) using the M06-2X/aug-cc-pVTZ level and stochastic RRKM-based Master equation rate model.

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.

Investigating Trends in Simulated Ignition Timing Across a Wide Range of Conditions Including Fuel Reactivity

2012 ◽  
Author(s):  
Michael V. Johnson ◽  
S. Scott Goldsborough ◽  
Timothy A. Smith ◽  
Steven S. McConnell
Keyword(s):  
Ignition Delay ◽  
Equivalence Ratio ◽  
Computational Cost ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Ignition Timing ◽  
Ignition Delay Times ◽  
Wide Range ◽  
Initial Work ◽  
Ci Engines

Continued interest in kinetically-modulated combustion regimes, such as HCCI and PCCI, poses a significant challenge in controlling the ignition timing due to the lack of direct control of combustion phasing hardware available in traditional SI and CI engines. Chemical kinetic mechanisms, validated based on fundamental data from experiments like rapid compression machines and shock tubes, offer reasonably accurate predictions of ignition timing; however utilizing these requires high computational cost making them impractical for use in engine control schemes. Empirically-derived correlations offer faster control, but are generally not valid beyond the narrow range of conditions over which they were derived. This study discusses initial work in the development of an ignition correlation based on a detailed chemical kinetic mechanism for three component gasoline surrogate, composed of n-heptane, iso-octane and toluene, or toluene reference fuel (TRF). Simulations are conducted over a wide range of conditions including temperature, pressure, equivalence ratio and dilution for a range of tri-component blends in order to produce ignition delay time and investigate trends in ignition as pressure, equivalence ratio, temperature and fuel reactivity are varied. A modified, Arrhenius-based power law formulation will be used in a future study to fit the computed ignition delay times.

Detailed Chemical Kinetic Modeling of JP-8/Jet-A Ignition and Combustion

2005 ◽  
Author(s):  
M. A. Mawid ◽  
T. W. Park ◽  
B. Sekar ◽  
C. Arana
Keyword(s):  
Reaction Mechanism ◽  
Air Force ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Us Air Force ◽  
The Us ◽  
Chemical Kinetic Mechanism ◽  
Ignition And Combustion ◽  
Surrogate Fuel ◽  
Detailed Chemical

Significant progress towards development and validation of a detailed chemical kinetic mechanism for the US Air Force JP-8 fuel is presented in this article. Three detailed chemical kinetic mechanisms for three JP-8 surrogate fuels, as given in Table I, were developed and reported in this study. The main objective is to investigate the performance of the developed three mechanisms for three different surrogate fuel blends and determine the suitability of each mechanism to chemically model the US Air Force petroleum-derived JP-fuel. The detailed JP-8 chemical kinetic reaction mechanism, we have been developing [1–3] for a 12-component surrogate fuel blend, has been used as a basis for the development of two additional detailed reaction mechanisms for the other two surrogate fuel mixtures. Submechanisms for the monosubstituted aromatics such as toluene, m-xylene, butylbenzene, and for the bicyclic aromatics such as 1-methylnaphthalene were all assembled and integrated with the detailed JP-8 reaction mechanism [1–3]. Pressure-dependent rate parameters up to 10 atmospheres for 41 reactions were also included. The three mechanisms were evaluated by predicting the ignition and combustion characteristics of a JP-8 fuel-air mixture in Plug Flow Reactor (PFR) and a Perfectly-Stirred Reactor (PSR) over a temperature range of 933–1020 K and pressure of 1 atm. The results indicated that overall the mechanism for the 6-component JP-8 surrogate 3 (Table I) can predict similar ignition-delay periods as those predicted by the 12-component JP-8 surrogate fuel 1 for atmospheric pressure condition. However, the PSR calculations pointed out to the existence of differences in lighter hydrocarbon species concentration profiles such as CH4, C2H4, C3H6, and C4H8 and important emission species such as CO and CO2 as predicted by the mechanisms that exhibited comparable ignition delay times. The study suggests that, for the conditions considered here, that the developed mechanisms still require further evaluation under various combustion environments, including transport phenomena, to determine the suitability of the chemical kinetic mechanism for either surrogate fuel 1 or 3 to chemically simulate the actual US Air Force JP-8 fuel.

A Detailed and Reduced Reaction Mechanism of Biomass-Based Syngas Fuels

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Marina Braun-Unkhoff ◽  
Nadezhda Slavinskaya ◽  
Manfred Aigner
Keyword(s):  
Reaction Mechanism ◽  
Laminar Flame ◽  
Chemical Kinetic ◽  
Laminar Flame Speed ◽  
Predictive Capability ◽  
Kinetic Reaction ◽  
Auto Ignition ◽  
Combustion Properties ◽  
Detailed Chemical ◽  
Good Agreement

In the present work, the elaboration of a reduced kinetic reaction mechanism is described, which predicts reliably fundamental characteristic combustion properties of two biogenic gas mixtures consisting mainly of hydrogen, methane, and carbon monoxide, with small amounts of higher hydrocarbons (ethane and propane) in different proportions. From the in-house detailed chemical kinetic reaction mechanism with about 55 species and 460 reactions, a reduced kinetic reaction mechanism was constructed consisting of 27 species and 130 reactions. Their predictive capability concerning laminar flame speed (measured at T0=323 K, 373 K, and 453 K, at p=1 bar, 3 bars, and 6 bars for equivalence ratios φ between 0.6 and 2.2) and auto ignition data (measured in a shock tube between 1035 K and 1365 K at pressures around 16 bars for φ=0.5 and 1.0) are discussed in detail. Good agreement was found between experimental and calculated values within the investigated parameter range.

Prediction of Premixed Laminar Flame Structure and Burning Velocity of Aviation Fuel-Air Mixtures

2001 ◽  
Author(s):  
A. G. Kyne ◽  
P. M. Patterson ◽  
M. Pourkashanian ◽  
C. W. Wilson ◽  
A. Williams
Keyword(s):  
Reaction Mechanism ◽  
Laminar Flame ◽  
Burning Velocity ◽  
Flame Structure ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Aviation Fuel ◽  
Measured Temperature ◽  
Premixed Laminar ◽  
Increasing Temperature

The structure of a rich burner stabilised kerosene/O2/N2 flame is predicted using a detailed chemical kinetic mechanism where the kerosene is represented by a mixture of n-decane and toluene. The chemical reaction mechanism, consisting of 440 reactions between 84 species, is capable of predicting the experimentally determined flame structure of Douté et al. (1995) with good success using the measured temperature profile as input. Sensitivity and reaction rate analyses are carried out to identify the most significant reactions and based on this the reaction mechanism was reduced to one with only 165 reactions without any loss of accuracy. Burning velocities of kerosene-air mixtures were also determined over an extensive range of equivalence ratios at atmospheric pressure. The initial temperature of the mixture was also varied and burning velocities were found to increase with increasing temperature. Burning velocities calculated using both the detailed and reduced mechanisms were essentially identical.

scholarly journals Development of a Chemical-Kinetic Mechanism of a Four-Component Surrogate Fuel for RP-3 Kerosene

ACS Omega ◽  
2021 ◽  
Vol 6 (36) ◽  
pp. 23485-23494
Author(s):  
Binbin Yu ◽  
Xinsheng Jiang ◽  
Donghai He ◽  
Chunhui Wang ◽  
Zituo Wang ◽  
...  
Keyword(s):  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Chemical Kinetic Mechanism ◽  
Surrogate Fuel
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