Article
Energy & Fuels
Guoxing Li, Youjun Lu, Hamid Hashemi, Peter Glarborg
Summary: A detailed chemical kinetic model was developed for high-pressure methanol oxidation in the gas phase and supercritical water, with updated kinetic parameters for key reactions. The model was validated against experimental data and showed good agreement overall, with discrepancies attributed to experimental artifacts. A comparative kinetic analysis explored the characteristic similarities and differences of methanol oxidation under the two conditions.
Article
Thermodynamics
Lingfeng Dai, Yi Yuan, Qianjin Lin, Wenyu Li, Chun Zou, Jiacheng Liu, Jianghui Luo
Summary: The ignition delay times (IDTs) of NH3/DMM mixtures at different DMM blending ratios were measured under specific conditions. A detailed DMM-NH3 model was proposed, which accurately predicted the IDTs and laminar flame speeds of NH3/DMM mixtures. The effects of various reactions, such as prompt NO and reburn reactions, recombination reactions, H-abstraction reactions, and disproportionation reactions, on ignition were discussed in detail.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Xin Li, Xianglin Chu, Zhihao Ma, Yifan Jin, Xin Wang, Zhideng Xi, Shiji Hu, Hao Chen
Summary: In this study, the ignition delay times (IDTs) of ammonia/ethanol mixtures with different ethanol fractions were measured and analyzed. The results showed that ethanol had a nonlinear and strong ignition-enhancing effect on the IDT of ammonia. A new ammonia/ethanol model was proposed to predict the experimental results reliably.
Article
Thermodynamics
Jinhu Liang, Chen Zhao, Ziwen Zhao, Xinhui Wang, Ming-Xu Jia, Quan-De Wang, Yang Zhang, Fengqi Zhao
Summary: This study investigates the high-temperature ignition and pyrolysis characteristics of cyclohexylamine through experimental and kinetic modeling approaches. The results show that the ignition delay times and pyrolysis product distributions of cyclohexylamine are influenced by temperature, pressure, and equivalence ratio. A detailed kinetic mechanism accurately predicts the experimental results. Sensitivity analysis identifies the most sensitive reaction as O2 + H = O + OH, and the abstraction reaction of cyclohexylamine with OH radical also exhibits significant sensitivity coefficients. Reaction path analysis reveals the control role of abstraction reactions in the initial oxidation of cyclohexylamine.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Can Yang, Weiye Wang, Yuhang Li, Xiaobei Cheng
Summary: This study evaluates the conversion of nitrogen oxides from NO to NO2 in the presence of oxygen and applies the results to simulations. Experimental results show that the addition of NO/NO2 promotes ignition, especially at lower temperatures and higher concentrations. The kinetic analysis suggests that certain reactions involving NO and NO2 may effectively produce OH radicals and promote ignition.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Lei Shi, Ping Xu, Rui Wang, Weixin Tang, Tao Ding, Rongpei Jiang, Changhua Zhang
Summary: The ignition delay times of JP-10 in air and the effect of NO2 on JP-10 autoignition were investigated in this study. Experimental results showed that the ignition delay times were influenced by pressure and equivalence ratio. The addition of NO2 promoted or inhibited the ignition of JP-10, depending on the pressure conditions. A chemical kinetic mechanism was developed and validated, and kinetics analyses were performed to further understand the ignition and vitiation effects.
Article
Thermodynamics
Chao Peng, Chun Zou, Wenxiang Xia, Qianjin Lin, Jianghui Luo, Haiyang Shi, Lixin Lu, Shusen Wang
Summary: Pressurized oxy-fuel combustion is considered an advanced technique with lower cost and little decrease in efficiency compared to conventional PC systems without CO2 capture. Experimental and modeling work on n-butane ignition delay times under different conditions validates the updated chemical kinetic model Oxymech2.0 Plus, which shows improved prediction accuracy for butane combustion in O2 / CO2 atmospheres. The effects of equivalence ratios and CO2 concentrations on the ignition delay times of n-butane were analyzed.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Yingtao Wu, Xiangdong Kong, Tao Yu, Zhaoming Mai, Shutong Cao, Qingwei Yu, Jinhu Liang, Shashank S. Nagaraja, S. Mani Sarathy, Zuohua Huang, Chenglong Tang
Summary: This study investigates the reactions between Tetramethylethylenediamine (TMEDA) and O2 under ignition conditions. Significant low-temperature reactivity and autoignition of 2% TMEDA/O2 mixtures were observed. Ignition delay times were measured in a rapid compression machine and a high-pressure shock tube, and TMEDA pyrolysis products were obtained in a single pulse shock tube. A hierarchical chemical kinetic model of TMEDA was developed and validated using experimental data, showing good predictions across different conditions.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Carolina S. Mergulhao, Yann Fenard, Goutham Kukkadapu, Scott W. Wagnon, Guillaume Vanhove
Summary: This study investigates the octane hyperboosting effect of prenol through experimental and kinetic modeling approaches. The results show that prenol addition reduces ignition phenomena and improves knock resistance. This behavior is attributed to gas-phase reactivity of prenol and a catalytic nature that cannot be captured by kinetic modeling.
Article
Energy & Fuels
Rui Wang, Ping Xu, Weixin Tang, Tao Ding, Changhua Zhang, Xiangyuan Li
Summary: This study investigated the autoignition characteristics of cyclopropane and found that temperature, pressure, and equivalence ratio have an impact on ignition delay time. Quantitative relationships were obtained through regression analysis, and a high-temperature combustion mechanism was developed. Reaction pathway and sensitivity analyses were conducted to determine key reactions affecting ignition delay time. Finally, comparisons and kinetic analyses were performed to interpret the ignition differences between cyclopropane and other fuels.
Article
Thermodynamics
Tao Ding, Weixin Tang, Rui Wang, Ping Xu, Dongxian Li, Changhua Zhang
Summary: Phenylacetylene plays a critical role in the formation of polycyclic aromatic hydrocarbons during petroleum combustion. In this study, the autoignition characteristics of phenylacetylene were investigated using reflected shock wave experiments. Ignition delay times were measured under different conditions, and quantitative relationships were obtained through regression analysis. The detailed oxidation mechanism of phenylacetylene was proposed and verified, and significant reaction pathways and key reactions affecting ignition delay time were investigated. A comparison of the ignition delay times of ethylbenzene, styrene, and phenylacetylene was also conducted, along with an analysis of the impact of different side chains on aromatic ring ignition.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Shangjun Li, Hongbiao Lu, Yebing Mao, Changhua Zhang, Sheng Huang, Rongpei Jiang, Quan Zhu, Huaqing Yang
Summary: Understanding the autoignition characteristics of fuels is crucial for engine design and combustion optimization. This study investigated the autoignition and chemical kinetics of 0# diesel, a typical diesel fuel designed for the Chinese national stage VI emission standard. Ignition delay times were measured over a wide range of conditions, and the effects of pressure and equivalence ratio on ignition delay times were analyzed. A kinetic model and a skeletal mechanism were developed to describe the reaction network of 0# diesel, and they accurately captured the autoignition characteristics. These findings provide valuable insights into the combustion progress of 0# diesel and can be used for numerical simulations.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Jiacheng Liu, Chun Zou, Jianghui Luo
Summary: Ammonia is a promising clean fuel due to its carbon-free nature and high hydrogen density, but its low reactivity and potential high NOx emissions limit its applications. Blending methane into ammonia enhances its reactivity, while lean combustion is an effective approach to control NOx emissions. This study developed a comprehensive kinetic model for ammonia/methane mixtures and found that it performs better than existing models.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Ping Xu, Rui Wang, Weixin Tang, Tao Ding, Dongxian Li, Changhua Zhang
Summary: Propylene glycol, a potential fuel additive, was investigated for its combustion behavior by studying the ignition delay times behind reflected shock waves. The effects of temperature, pressure, fuel and oxygen concentrations were analyzed, and a detailed oxidation mechanism was proposed. H-abstraction reactions were found to be the main consumption channels of propylene glycol, and C-C bond dissociation reactions also played a significant role. Comparison with other fuel compounds was conducted to evaluate the ignition delay time.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Tanusree Chatterjee, Chiara Saggese, Shijun Dong, Vaibhav Patel, Katherine S. Lockwood, Henry J. Curran, Nicole J. Labbe, Scott W. Wagnon, William J. Pitz
Summary: The low temperature oxidation kinetics of pentanol isomers, including 1-pentanol, 2-pentanol, and 3-pentanol, have been studied in this research. A newly developed kinetic mechanism based on recent experimental and theoretical calculations accurately predicts the combustion performance of these three pentanol isomers. The comprehensive validation of the proposed kinetic model shows satisfactory qualitative and quantitative predictions when compared to experimental data.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Wenjun Lin, Wang Han, Jinhua Wang, Runze Mao, Weijie Zhang, Xiao Cai, Zuohua Huang
Summary: The role of low-temperature chemistry/ignition (LTC/LTI) was studied in aero engine-like combustors with confined bluff-body and swirling flows. Experimental investigations were conducted on CH4/DME/air mixtures with varying DME volume fraction (αDME) to consider LTI. It was found that adding DME to lean CH4/air mixtures can introduce low-temperature flames (LTF) in the outer recirculation zone (ORZ) under certain conditions. The flame regimes were classified based on DME enrichment, and the possibility of using LTI to extend the stability margin of lean swirling flames was demonstrated.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Hongchao Dai, Jinhua Wang, Xiao Cai, Shouguo Su, Haoran Zhao, Zuohua Huang
Summary: This study investigates the impact of Lewis number (Le) on laminar and turbulent expanding flames of NH3/H2/air mixtures. The results show that the laminar burning velocity (SL) is significantly affected by the diffusional-thermal instability, which dominates the trend of turbulent burning velocity (ST) with the equivalence ratio (φ) for lean mixtures. The turbulent flame of NH3/H2/air mixtures exhibits self-similar acceleration propagation, with faster propagation observed when Le < 1. A modified correlation considering the effects of Le is proposed, which accurately predicts the propagation of NH3/H2/air mixtures as well as other syngas/air flames.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Yingtao Wu, Xiangdong Kong, Tao Yu, Zhaoming Mai, Shutong Cao, Qingwei Yu, Jinhu Liang, Shashank S. Nagaraja, S. Mani Sarathy, Zuohua Huang, Chenglong Tang
Summary: This study investigates the reactions between Tetramethylethylenediamine (TMEDA) and O2 under ignition conditions. Significant low-temperature reactivity and autoignition of 2% TMEDA/O2 mixtures were observed. Ignition delay times were measured in a rapid compression machine and a high-pressure shock tube, and TMEDA pyrolysis products were obtained in a single pulse shock tube. A hierarchical chemical kinetic model of TMEDA was developed and validated using experimental data, showing good predictions across different conditions.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Hu Liu, Wenjun Lin, Qianqian Li, Haoran Zhao, Zuohua Huang
Summary: The laminar flame speeds of five cyclic hydrocarbon fuels were studied, and the differences among them were identified. The thermal, diffusional, and chemical effects that contribute to the flame speed differences were discussed. A refined model showed good performance in predicting the flame speeds except for one fuel, and a quantitative comparison of the mole fractions of certain elements in the flames provided further insights into the reactivities of the fuels.
Article
Thermodynamics
Bowen Liu, Erjiang Hu, Geyuan Yin, Zuohua Huang
Summary: The laminar burning velocities (LBVs) of ammonia (NH3) blended with ethylene (C2H4) were investigated under different blending ratios, initial temperatures, and initial pressures. The flame morphology showed cellular instability under elevated pressures. The thermal diffusion instability was evaluated using the Lewis number (Le) and was found to be positively correlated with the blending ratio.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Haoran Zhao, Gang Li, Jinhua Wang, Zuohua Huang
Summary: In this study, the turbulent expanding flames of hydrogen/air mixtures were investigated over a wide range of equivalence ratios using a fan-stirred combustion chamber. The effects of molecular transport on turbulent flame propagation were analyzed, including flame morphology, turbulent burning velocity, and their correlations. It was found that the wrinkled degree of the turbulent flame surface was stronger under fuel-lean conditions and the flame morphology became more wrinkled as it propagated outwardly. The peak turbulent burning velocity occurred at fuel-lean conditions and the effects of molecular transport were enhanced under intense turbulent field.
Article
Chemistry, Applied
Zhiyu Yan, Yilan Yang, Qianqian Li, Yingwen Yan, Zemin Tian, Chen Song, Zuohua Huang
Summary: The effects of NH3 and/or H2 addition on soot formation and gas emission in a laminar ethylene diffusion flame were studied. NH3 addition can suppress PAH and soot formation by both dilutive and chemical effects, while H2 addition chemically promotes soot formation. The soot formation of NH3-H2 blends is between flames doped with pure NH3 and H2.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Applied
Yibo Gao, Erjiang Hu, Yang Yi, Geyuan Yin, Zuohua Huang
Summary: In this study, ceria-based catalysts with three morphologies (CeO2-C, CeO2-R, CeO2-S) doped with 3d transition metals have been used in ammonia decomposition reaction (ADR), showing excellent catalytic performance. The FeCo/CeO2-S catalyst exhibited the highest ammonia conversion rate and hydrogen generation rate.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Thermodynamics
Chuansheng Liu, Chenglong Tang, Qingchen Ma, Zuohua Huang, Peng Zhang, Feng Zhang
Summary: Liquid film cooling by jet-wall impingement is commonly used in small rocket engines. A comprehensive analytical model for the liquid film flow is established and validated through experiments. The predicted dimensions of the liquid film agree well with experimental results. The impingement angle and velocity, as well as surface tension and viscosity, have significant effects on the dimensions of the liquid film. An empirical correlation for the film dimensional parameters is proposed.
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER
(2023)
Article
Thermodynamics
Xiao Cai, Shouguo Su, Limin Su, Jinhua Wang, Marcus Alden, Zhongshan Li, Zuohua Huang
Summary: In this study, the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames is demonstrated. It is found that intense turbulence can cause the strong burning of iron-methane hybrid mixture with separated dual-front or merged single-front structures. The formation of iron flame front is attributed to local iron concentration accumulation, enhanced heat transfer of iron particles, and mixing promotion of iron particles with oxidants by strong turbulence. Additionally, strong self-similar propagation of the hybrid flame is observed under different turbulence intensities, which is influenced by flame mode transition and differential diffusion.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Haoran Zhao, Jinhua Wang, Xiao Cai, Hongchao Dai, Xiao Liu, Gang Li, Zuohua Huang
Summary: This study investigates the accelerative propagation of laminar and turbulent premixed hydrogen/air flames in a constant volume combustion chamber. The results show that laminar flame propagation has three distinct stages, while turbulent flame propagation follows a continuous acceleration law without a clear transition point.
Article
Thermodynamics
Rongyuan Ju, Jinhua Wang, Meng Zhang, Haibao Mu, Guanjun Zhang, Jinlu Yu, Zuohua Huang
Summary: This study investigates the effects of rotating gliding arc (RGA) discharge plasma on the flame stability and NOx emission of NH3/air premixed swirling flames. The discharge characteristics of the RGA were studied, and the flame stabilization mechanisms by plasma were revealed and analyzed. The results show that the RGA discharge plasma can enhance flame stability and reduce NOx emissions by affecting flame structure and key intermediate OH radicals distribution.
Article
Mechanics
Xiao Cai, Limin Su, Jinhua Wang, Erjiang Hu, Zuohua Huang
Summary: This study experimentally investigated the transition to cellularity and self-similar propagation of flames in reactive environments. The results show that the critical radius for cellular instability varies non-monotonously with initial pressure, and the critical Peclet number increases non-linearly with the Markstein number. The theory provides a quantitative agreement with the experimental results and predicts the linear dependence of Pe(cr) on Ma.
Article
Energy & Fuels
Ruihan Ge, Erjiang Hu, Xiaoxin Yao, Chenglong Tang, Zuohua Huang
Summary: This experimental study investigates the effects of ignition timings, injection pressures, and hydrogen enrichment on ethanol stratified ultra-lean combustion. The results show that the addition of hydrogen increases the stable ignition limit and improves combustion characteristics. However, delayed ignition timings and high injection pressures may result in incomplete combustion.
Article
Thermodynamics
Longjuan Ji, Jinhua Wang, Weijie Zhang, Deli Li, Guangya Hu, Zuohua Huang
Summary: The nonlinear behavior of thermoacoustic oscillation for premixed swirl flames fueled with CH4/air mixtures is experimentally studied. The study reveals the effects of changing equivalence ratio phi, combustor inlet bulk velocity Uin, and swirl number S on the flame modes and oscillations. The study also shows the relationship between the appearance of flame in the outer circulation zone and the occurrence of quasi-periodic and limit cycle oscillations. Furthermore, the study finds that the lean/rich blow-off limits and oscillation range are extended with a larger S, while the stable combustion regime is wider with a smaller S.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
