Theoretical Prediction of the Effect of Blending JP-8 With Syngas on the Ignition Delay Time and Laminar Burning Speed

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Guangying Yu ◽  
Omid Askari ◽  
Hameed Metghalchi
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Large Range ◽  
Numerical Study ◽  
Chemical Mechanism ◽  
One Dimensional ◽  
Volume Model ◽  
The Impact ◽  
Laminar Burning Speed

A numerical study has been carried out to investigate the impact of adding syngas into JP-8 fuel. A new chemical mechanism has been assembled from existing mechanism of JP-8 and syngas and has been examined by comparing with the experimental data from literatures. The mechanism was then applied to Cantera zero-dimension constant internal energy and constant volume model and one-dimensional (1D) freely propagating flame model to calculate the ignition delay time and laminar burning speed, respectively. The simulations were carried out over a large range of temperature (700–1000 K), blending ratio (0–20% syngas), and H2/CO ratio (10/90 to 50/50). Simulation results showed that the blending syngas with JP-8 will slightly increase the ignition delay time and laminar burning speed.

Numerical study on laminar burning velocity and ignition delay time of ammonia flame with hydrogen addition

Energy ◽  
2017 ◽  
Vol 126 ◽  
pp. 796-809 ◽  
Author(s):  
Jun Li ◽  
Hongyu Huang ◽  
Noriyuki Kobayashi ◽  
Chenguang Wang ◽  
Haoran Yuan
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Numerical Study ◽  
Burning Velocity ◽  
Laminar Burning Velocity ◽  
Hydrogen Addition

Numerical Study on the Effect of Real Syngas Compositions on Ignition Delay Times and Laminar Flame Speeds at Gas Turbine Conditions

2013 ◽  
Author(s):  
Olivier Mathieu ◽  
Eric L. Petersen ◽  
Alexander Heufer ◽  
Nicola Donohoe ◽  
Wayne Metcalfe ◽  
...  
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Gas Turbines ◽  
Ignition Delay Time ◽  
Laminar Flame ◽  
Numerical Study ◽  
Fuel Mixture ◽  
Flame Speed ◽  
Operating Conditions ◽  
Combustion Properties

Depending on the feedstock and the production method, the composition of syngas can include (in addition to H2 and CO) small hydrocarbons, diluents (CO2, water, and N2), and impurities (H2S, NH3, NOx, etc.). Despite this fact, most of the studies on syngas combustion do not include hydrocarbons or impurities and in some cases not even diluents in the fuel mixture composition. Hence, studies with realistic syngas composition are necessary to help designing gas turbines. The aim of this work was to investigate numerically the effect of the variation in the syngas composition on some fundamental combustion properties of premixed systems such as laminar flame speed and ignition delay time at realistic engine operating conditions. Several pressures, temperatures, and equivalence ratios were investigated. To perform this parametric study, a state-of-the-art C0-C5 detailed kinetics mechanism was used. Results of this study showed that the addition of hydrocarbons generally reduces the reactivity of the mixture (longer ignition delay time, slower flame speed) due to chemical kinetic effects. The amplitude of this effect is however dependent on the nature and concentration of the hydrocarbon as well as the initial condition (pressure, temperature, and equivalence ratio).

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.

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>

scholarly journals A Simplified and Optimized Chemical Mechanism for Combustion of n-Pentane at Atmospheric Pressure

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 884
Author(s):  
Zhiqun Meng ◽  
Jinggang Wang ◽  
Jiawen Qi ◽  
Chuchao Xiong ◽  
Liquan Hou ◽  
...  
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Laminar Flame ◽  
Combustion Process ◽  
Maximum Error ◽  
Chemical Mechanism ◽  
Detailed Mechanism ◽  
Applicable Range ◽  
Simplified Mechanism

In the present study, the detailed mechanism of n-pentane combustion, including 697 species and 3214 reactions, is first simplified to a mechanism with only 26 species and 134 reactions, which is suitable for the pressure of 1 atm, temperatures of 1000–1600 K, and equivalent ratios of 0.5–1.6. However, when the equivalence ratio is 1.0, in the temperature range of 1000–1100 K, compared with the detailed mechanism, the maximum error of the ignition delay time predicted by the simplified mechanism exceeds 20%. Therefore, based on the method of temperature sensitivity analysis, the simplified mechanism is further utilized through reducing the A-factor of 2HO2 = H2O2 + O2 (−1) and 2HO2 = H2O2 + O2 (−2) by 10 times. By comparing with the detailed mechanism and predicting the ignition delay time, laminar flame speed, species profile, and extinction residence time, it is found that the optimized mechanism has good accuracy in the applicable range, and is fully capable of simulating the combustion process of light hydrocarbon gas.

Kinetic Modeling of Plasma-Enhanced Vitiated Combustion

2015 ◽  
Author(s):  
Richard G. Joklik ◽  
Ponnuthurai Gokulakrishnan ◽  
Michael S. Klassen
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Kinetic Mechanism ◽  
Pulsed Plasma ◽  
Direct Production ◽  
Temperature Oxidation ◽  
Electronically Excited ◽  
Combustion Systems ◽  
The Impact

Plasma-enhanced combustion can improve the performance of combustion systems for which ignition and flameholding are issues through augmentation of radical species concentrations. Electron impact generates electronically excited N2 and O2, both of which participate in reactions that create atomic oxygen and nitrogen. OH and H concentrations are also altered, both through equilibration of the radical pool, and through direct production pathways from the excited N2 and O2. In the case of vitiated combustion, it has been demonstrated that the presence of NO in the oxidizer stream enhances ignition. However, the impact of the plasma-enhanced radical pool on the effects of vitiation is unknown. It was the goal of this work to explore the impact of plasma-generated species on vitiated kinetics, and the resulting effect on ignition. In this paper we describe the development and validation of a model for ethylene-air ignition by a nanosecond pulsed-plasma. The model employs a zero-dimensional simulation of the plasma to predict the radical concentrations produced by the plasma. These concentrations are then used as input to an ignition delay time calculation using a kinetic mechanism for vitiated combustion that has been previously developed by the authors. The modeling results show that the O-atom, H-atom, N-atom and C2H3 production by the plasma are important in determining ignition delay. The ignition delay time calculations show that both vitiation and plasma effects are important in determining ignition delay, with the plasma effect becoming dominant as the plasma strength is increased, especially in the low-temperature oxidation regime. Thus in designing practical plasma-assisted combustion systems, an understanding of these effects is important in determining the plasma requirements to achieve the desired level of combustion enhancement.

Understanding the Effect of Oxygenated Additives on Combustion Characteristics of Gasoline

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Shrabanti Roy ◽  
Saeid Zare ◽  
Omid Askari
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Combustion Characteristics ◽  
Characteristic Change ◽  
Time Behavior ◽  
Alternative Source ◽  
Oxygenated Additives ◽  
Wide Range ◽  
Laminar Burning Speed

Laminar burning speed and ignition delay time behavior of iso-octane at the presence of two different biofuels, ethanol and 2,5 dimethyl furan (DMF), was studied in this work. Biofuels are considered as a better alternative source of fossil fuels. There is a potentiality that combustion characteristics of iso-octane can be improved using biofuels as an oxygenated additive. In this study, three different blending ratios of 5%, 25%, and 50% of ethanol/iso-octane and DMF/iso-octane were investigated. For laminar burning speed calculation, equivalence ratio of 0.6–1.4 was considered. Ignition delay time was measured under temperature ranges from 650 K to 1100 K. Two different mechanisms were considered in numerical calculation. These mechanisms were validated by comparing the results of pure fuels with wide range of experimental and numerical data. The characteristic change of iso-octane with the presence of additives was observed by comparing the results with pure fuel. Significant change was observed on behavior of iso-octane at 50% blending ratio. A comparison was also done on the effect of two different additives. It has found that addition of DMF brings significant changes on iso-octane characteristics comparing to ethanol.

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