An Investigation of Various Chemical Kinetic Models for the Prediction of Autoignition in HCCI Engine

2012 ◽  
Author(s):  
A. F. Khan ◽  
A. A. Burluka
Keyword(s):  
Kinetic Models ◽  
Chemical Kinetic ◽  
Compression Ignition Engine ◽  
Engine Model ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Weak Points ◽  
Different Levels

Diverse kinetic models for iso-octane, n-heptane, toluene and ethanol i.e. main gasoline surrogates, have been investigated. The models have different levels of complexity and strong and weak points. Firstly, ignition delay times for various fuel blends have been calculated and compared with published shock tube measurements. Kinetic models which are capable of distinguishing between Primary and Toluene Reference Fuels have been used further on in a zero-dimensional Homogeneous Charge Compression Ignition engine model to predict auto-ignition. The modelling results have been compared to the experimental results obtained in a single cylinder research engine. A discussion has been made on the ability of these models to predict autoignition.

Auto Ignition Study of Methane and Bio Alcohol Fuel Blends

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Xuan Zheng ◽  
Shirin Jouzdani ◽  
Benjamin Akih-Kumgeh
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Dual Fuel ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Alcohol Fuel ◽  
Delay Times

Abstract Methane (CH4) and bio alcohols have different ignition properties. These have been extensively studied and the resulting experimental data have been used to validate chemical kinetic models. Methane is the main component of natural gas, which is of interest because of its relative availability and lower emissions compared to other hydrocarbon fuels. Given growing interest in fuel-flexible systems, there can be situations in which the combustion properties of natural gas need to be modified by adding biofuels such as bio alcohols. This can occur in dual-fuel internal combustion engines or gas turbines with dual-fuel capabilities. The combustion behavior of such blends can be understood by studying the auto ignition properties in fundamental combustion experiments. Studies of the ignition of such blends are very limited in the literature. In this work, the auto ignition of methane and bio alcohol fuel blends is investigated using a shock tube facility. The chosen bio alcohols are ethanol (C2H5OH) and n-propanol (NC3H7OH). Experiments are carried out at 3 atm and 10 atm for stoichiometric and lean mixtures of fuel, oxygen, and argon. The ignition delay times of the pure fuels are first established at conditions of constant oxygen concentration and comparable pressures. The ignition delay times of blends with 50% methane are then measured. The pyrolysis kinetics of the blends is further explored by measuring CO formation during pyrolysis of the alcohol and methane–alcohol blends. The resulting experimental data are compared with the predictions of selected chemical kinetic models to establish the ability of these models to predict the disproportionate enhancement of methane ignition by the added alcohol.

Auto Ignition Study of Methane and Bio Alcohol Fuel Blends

2019 ◽  
Author(s):  
Xuan Zheng ◽  
Shirin Jouzdani ◽  
Benjamin Akih-Kumgeh
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Dual Fuel ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Alcohol Fuel ◽  
Delay Times

Abstract Methane (CH4) and bio alcohols have different ignition properties. These have been extensively studied and the resulting experimental data have been used to validate chemical kinetic models. Methane is the main component of natural gas, which is of interest because of its relative availability and lower emissions compared to other hydrocarbon fuels. Given growing interest in fuel-flexible systems, there can be situations in which the combustion properties of natural gas need to be modified by adding biofuels, such as bio alcohols. This can occur in dual fuel internal combustion engines or gas turbines with dual fuel capabilities. The combustion behavior of such blends can be understood by studying the auto ignition properties in fundamental combustion experiments. Studies of the ignition of such blends are very limited in the literature. In this work, the auto ignition of methane and bio alcohol fuel blends is investigated using a shock tube facility. The chosen bio alcohols are ethanol (C2H5OH) and n-propanol (NC3H7OH). Experiments are carried out at 3 atm and 10 atm for stoichiometric and lean mixtures of fuel, oxygen, and argon. The ignition delay times of the pure fuels are first established at conditions of constant oxygen concentration and comparable pressures. The ignition delay times of blends with 50% methane are then measured. The pyrolysis kinetics of the blends is further explored by measuring CO formation during pyrolysis of the alcohol and methane-alcohol blends. The resulting experimental data are compared with the predictions of selected chemical kinetic models to establish the ability of these models to predict the disproportionate enhancement of methane ignition by the added alcohol.

Experimental Study on Ethane Ignition Delay Times and Evaluation of Chemical Kinetic Models

2015 ◽  
Vol 29 (7) ◽  
pp. 4557-4566 ◽  
Author(s):  
Erjiang Hu ◽  
Yizhen Chen ◽  
Zihang Zhang ◽  
Xiaotian Li ◽  
Yu Cheng ◽  
...  
Keyword(s):  
Experimental Study ◽  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Ignition Delay Times ◽  
Delay Times

Influences of isomeric butanol addition on anti-knock tendency of primary reference fuel and toluene primary reference fuel gasoline surrogates

2019 ◽  
Vol 22 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Yunchu Fan ◽  
Yaozong Duan ◽  
Dong Han ◽  
Xinqi Qiao ◽  
Zhen Huang
Keyword(s):  
Combustion Kinetics ◽  
Molar Percentage ◽  
Research Octane Number ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Primary Reference ◽  
Primary Reference Fuels

The anti-knock tendency of blends of butanol isomers and two gasoline surrogates (primary reference fuels and toluene primary reference fuels) was studied on a single-cylinder cooperative fuel research engine. The effects of butanol molecular structure (n-butanol, i-butanol, s-butanol and t-butanol) and butanol addition percentage on fuel research octane numbers were investigated. The experimental results revealed that butanol addition to either PRF80 or TPRF80 increased research octane numbers, and the research octane numbers of fuel blends showed higher linearity with the molar percentage than with the volumetric percentage of butanol addition. Furthermore, the research octane number boosting effects of butanol isomers were observed to change with the fuel compositions, that is, i-butanol >s-butanol >n-butanol >t-butanol for primary reference fuels and i-butanol >s-butanol >t-butanol >n-butanol for toluene primary reference fuels. In addition, butanol/primary reference fuel blends exhibited higher research octane numbers than butanol/toluene primary reference fuel blends. We thereafter tried to elucidate the underlying fuel combustion kinetics for the observed anti-knock quality of different butanol/gasoline surrogate blends. It was found that the measured research octane numbers of fuel blends showed the best correlation with the calculated ignition delay times at the thermodynamic condition of 770 K and 2 MPa, and the reaction sensitivity analysis in auto-ignition at this condition revealed that the H-abstraction reactions of butanol isomers by OH radical suppressed fuel reactivity, thus elevating the fuel research octane numbers when butanol was added to the gasoline surrogates. Compared with the butanol/primary reference fuel blends, the positive sensitive reactions related to n-heptane were of higher importance, while the inhibitive effects of sensitive reactions related to butanol and iso-octane decreased for the toluene primary reference fuel/butanol blends, thus leading to lower research octane numbers of the toluene primary reference fuel/butanol blends than those of the butanol/primary reference fuel blends.

Reduced Chemical Kinetic Models of C1 - C4 Alcohols Using the Alternate Species Elimination Approach

2019 ◽  
Author(s):  
Apeng Zhou ◽  
Shirin Jouzdani ◽  
Ben Akih-Kumgeh
Keyword(s):  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Chemical Kinetic Model ◽  
Detailed Model ◽  
Elementary Reactions ◽  
Reduced Models ◽  
Ignition Delay Times ◽  
Combustion Properties ◽  
Delay Times

Abstract This study presents four separate reduced chemical kinetic models of methanol/ethanol, propanol isomers, n- and iso-butanol, and n- and s-butanol isomers, derived from a comprehensive chemical kinetic model of C1-C5 alcohols using the Alternate Species Elimination approach. It is motivated by complexity of the detailed model (comprising 600 species and 4100 elementary reactions) and the need for simpler kinetic models for analysis of combustion of smaller alcohols. The reduced models are obtained on the basis of ignition delay time simulations with imposed thresholds on the resulting normalized changes in ignition delay times. The following reduced models are obtained: methanol/ethanol: 38 species and 197 reactions; propanol isomers: 68 species and 419 reactions; n- and iso-butanol: 140 species and 745 reactions; and n- and s-butanol: 134 species and 739 reactions. Predictions of ignition delay times by the reduced models are found to be in good with the detailed models. The reduced models are further tested against other relevant combustion properties. These properties include burning velocities of laminar premixed flames, global pyrolysis time scales, and heat release timing in Homogeneous Charge Compression Ignition engines. This verification shows that reduced models can replace the comprehensive model in combustion analysis without loss of predictive performance. The reduced models can also serve as starting models for developing combined chemical kinetic models of gasoline/diesel and alcohol blends.

scholarly journals Numerical investigations on hydrogen-enhanced combustion in ultra-lean gasoline spark-ignition engines

2019 ◽  
pp. 146808741987068 ◽  
Author(s):  
Nicolas Iafrate ◽  
Mickael Matrat ◽  
Jean-Marc Zaccardi
Keyword(s):  
Ignition Delay ◽  
Combustion Process ◽  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Numerical Investigations ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Combustion Speed

Performance of lean-burn gasoline spark-ignition engines can be enhanced through hydrogen supplementation. Thanks to its physicochemical properties, hydrogen supports the flame propagation and extends the dilution limits with improved combustion stability. These interesting features usually result in decreased emissions and improved efficiencies. This article aims at demonstrating how hydrogen can support the combustion process with a modern combustion system optimized for high dilution resistance and efficiency. To achieve this, chemical kinetics calculations are first performed in order to quantify the impacts of hydrogen addition on the laminar flame speed and on the auto-ignition delay times of air/gasoline mixtures. These data are then implemented in the extended coherent flame model and tabulated kinetics of ignition combustion models in a specifically updated version of the CONVERGE code. Three-dimensional computational fluid dynamics engine calculations are performed at λ = 2 with 3% v/v of hydrogen for two operating points. At low load, numerical investigations show that hydrogen enhances the maximal combustion speed and the flame growth just after the spark which is a critical aspect of combustion with diluted mixtures. The flame front propagation is also more isotropic when supported with hydrogen. At mid load, hydrogen improves the combustion speed and also extends the auto-ignition delay times resulting in a better knocking resistance. A maximal indicated efficiency of 48.5% can thus be reached at λ = 2 thanks to an optimal combustion timing.

scholarly journals Aerosol Shock Tube Designed for Ignition Delay Time Measurements of Low-Vapor-Pressure Fuels and Auto-Ignition Flow-Field Visualization

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 683
Author(s):  
Erwei Liu ◽  
Qin Liao ◽  
Shengli Xu
Keyword(s):  
Flow Field ◽  
Vapor Pressure ◽  
Shock Tube ◽  
Ignition Delay ◽  
Pressure Sensors ◽  
Local Pressure ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Sequential Images

An aerosol shock tube has been developed for measuring the ignition delay times (tig) of aerosol mixtures of low-vapor-pressure fuels and for visualization of the auto-ignition flow-field. The aerosol mixture was formed in a premixing tank through an atomizing nozzle. Condensation and adsorption of suspended droplets were not observed significantly in the premixing tank and test section. A particle size analyzer was used to measure the Sauter mean diameter (SMD) of the aerosol droplets. Three pressure sensors and a photomultiplier were used to detect local pressure and OH emission respectively. Intensified charge-coupled device cameras were used to capture sequential images of the auto-ignition flow-field. The results indicated that stable and uniform aerosol could be obtained by this kind of atomizing method and gas distribution system. The averaged SMD for droplets of toluene ranged from 2 to 5 μ m at pressures of 0.14–0.19 MPa of dilute gases. In the case of a stoichiometric mixture of toluene/O2/N2, ignition delay times ranged from 77 to 1330 μs at pressures of 0.1–0.3 MPa, temperatures of 1432–1716 K and equivalence ratios of 0.5–1.5. The logarithm of ignition delay times was approximately linearly correlated to 1000/T. In contrast to the reference data, ignition delay times of aerosol toluene/O2/N2 were generally larger. Sequential images of auto-ignition flow-field showed the features of flame from generation to propagation.

scholarly journals Simulation of the Oxidation and Combustion of Mixed Diesel-Biodiesel Fuel

2018 ◽  
Vol 156 ◽  
pp. 03008
Author(s):  
Yuswan Muharam ◽  
Danny Leonardi ◽  
Alisya P Ramadhania
Keyword(s):  
Kinetic Model ◽  
Kinetic Models ◽  
Equivalence Ratio ◽  
Biodiesel Fuel ◽  
Ignition Delay Times ◽  
Simulation Based ◽  
Delay Times ◽  
Set Up ◽  
Biodiesel Fuels ◽  
Good Agreement

A comparative simulation-based research has been set up to obtain valid kinetic models of the oxidation and combustion of biodiesel surrogate and diesel surrogate, as well as mixed diesel-biodiesel surrogates which is used to predict their ignition delay times (IDT). The research consists of the development of the detailed kinetic models of the oxidation and combustion of biodiesel surrogate and diesel surrogate, the validation of the two models with the corresponding experimental IDT data, the merging and the validation of the two models for mixed diesel-biodiesel surrogates. The biodiesel surrogate kinetic model was validated with the experimental IDT data of methyl 9-decenoate at 20 atm and three equivalence ratios. The diesel surrogate kinetic model was validated with the experimental IDT data of n-hexadecane at the pressure ranging from 2 atm to 5 atm and the equivalence ratio of 1.0. The diesel-biodiesel surrogate kinetic model was validated with the experimental IDT data of real diesel-biodiesel fuels for four compositions and at 1.18 atm. The validation results of all models show that the models and the experiments are in good agreement.

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