Article
Thermodynamics
Hamed Shariatmadar, Pavlos G. Aleiferis, R. P. Lindstedt
Summary: This study presents experimental data on the size distribution of soot particles and investigates the variation of particle size distribution in turbulent flames under different conditions.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Can Shao, Felipe Campuzano, Yitong Zhai, Haoyi Wang, Wen Zhang, S. Mani Sarathy
Summary: This study investigated particle size distributions and chemical compositions of soot in ethylene-oxygen flames with and without ammonia doping. The results showed that ammonia doping inhibits soot formation and decreases the size and volume fraction of soot particles. This was attributed to the generation of C-N species in ethylene-ammonia flames, which prevented carbon from participating in soot precursor formation.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
H. Shariatmadar, F. Hampp, R. P. Lindstedt
Summary: This study quantifies the impact of equivalence ratio and rate of strain on the spatial distribution of major species and soot precursors in premixed turbulent ethylene flames crossing the soot inception limit. The results show that rate of strain exerts a dominant impact on the growth of soot particles and acetylene, 1-methylnaphthalene are correlated with soot formation. The study suggests that the equivalence ratio is the controlling PAH growth parameter.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Chen Zhang, Yimeng Wu, Biaojie Liu, Ziwen Wang, Lei Zhou
Summary: This study investigates the morphology and structure of soot particles in laminar diffusion flames of anisole/n-heptane, and proposes a set of fractal-based distribution analysis algorithms. The addition of anisole greatly influences the soot formation process, resulting in formation at a lower position in the flame and larger primary particle diameters.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Francisco Cepeda, Rodrigo Demarco, Felipe Escudero, Juan Jose Cruz Villanueva, Gonzalo Carvajal, Andres Fuentes
Summary: This study investigated the relationship between soot concentration and temperature, and provided new data for time-dependent numerical simulations by measuring local radiative heat flux on transient laminar flames. Results showed that forced condition significantly changed soot production, temperature distribution, and radiative properties, enhancing flame radiation.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Zhixuan Zhang, Xu Han, Mingda Wang, Zhengjie Wu, Xiang Sun, Shaohua Wu
Summary: A new and robust numerical approach, called the hybrid sectional moment projection method, is proposed for solving the population balance equations in laminar premixed flames. This approach combines the fixed sectional method and moment projection method, and adopts a number of quadrature nodes within each section to describe complex particle interactions. Testing and simulation results show that the new approach outperforms the conventional fixed sectional method in terms of numerical accuracy and computational efficiency.
Article
Energy & Fuels
Hong-Quan Do, Luc-Sy Tran, Laurent Gasnot, Xavier Mercier, Abderrahman El Bakali
Summary: Experimental investigation on methane premixed flames with and without hydrogen showed that the introduction of hydrogen has insignificant impact on the maximum mole fractions of small species in the flame.
Article
Thermodynamics
Christopher Betrancourt, Damien Aubagnac-Karkar, Xavier Mercier, Abderrahman El-Bakali, Pascale Desgroux
Summary: This study investigates nucleation flames and their contribution to soot formation and growth. Experimental measurements and modeling simulations of flames with different equivalence ratios were conducted. The results show that nucleation flames produce very small-sized soot particles with negligible growth. The study validates the capability of the combustion model to predict soot volume fraction and emphasizes the need for improvements in particle inception modeling.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Hong-Quan Do, Alessandro Faccinetto, Luc-Sy Tran, Pascale Desgroux, Laurent Gasnot, Abderrahman El Bakali, Xavier Mercier
Summary: This study reports new experimental data on the impact of H-2 on slightly sooting methane flames. It shows that the introduction of H-2 strongly influences the formation of aromatic species and soot, as well as the nucleation and growth processes of the soot particles. The study also presents a novel analytical methodology for determining the volume fraction and size density function of soot particles.
Article
Thermodynamics
A. V. Drakon, E. V. Gurentsov, A. V. Eremin, R. N. Kolotushkin, E. S. Khodyko, H. Jander
Summary: This paper presents the experimental and calculated results of investigating the soot formation in a premixed ethylene/air flame with the addition of dimethyl ether. The experimental results show that the addition of dimethyl ether affects the soot volume fraction. The kinetic modeling and analysis reveal the importance of benzene formation as a precursor to soot.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Hope A. Michelsen, Emeric Boigne, Paul E. Schrader, K. Olof Johansson, Matthew F. Campbell, Ray P. Bambha, Matthias Ihme
Summary: We have developed a new method for extracting particulates and gas-phase species from flames by directing a small jet of inert gas through the flame to collect the sample. This approach allows for quenching and diluting the sample during extraction while minimizing the perturbations to the flame. Experimental results, TEM analysis, and numerical simulations demonstrate the significant advantages of this jet-entrainment sampling technique.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Mengting Si, Qiang Cheng, Lin Yuan, Zixue Luo, Zuwei Xu, Haibo Zhao
Summary: The chemical composition, oxidation reactivity, nanostructure, and particle size of two coal-derived soot were investigated experimentally. The soot samples were collected from single coal combustion flames and analyzed using various techniques. The results showed differences in surface chemistry and oxidation reactivity between the two kinds of soot. Furthermore, the nanostructure and particle size distribution of the soot were influenced by flame height.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Myunggeun Ahn, Taesung Kim, Youngbin Yoon
Summary: A comparative study was conducted on the response characteristics of non-premixed and premixed flames under acoustic excitation conditions. The study found that the flame fluctuation amplitude in non-premixed flames is influenced by the forcing frequency and velocity perturbation intensity, while in premixed flames, there is a linear correlation between flame height and Strouhal number and FTF gain. Furthermore, introducing flame height perturbation parameters can simplify the analysis of heat-release rate.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Energy & Fuels
R. Jalain, J. Bonnety, G. Legros, A. Matynia
Summary: This study investigated the impact of adding alcohols to fuel mixtures on soot emissions in internal combustion engines. Analysis using gas chromatography revealed differences in intermediate species and alkene production due to the addition of different alcohols. The results provide new insights into the effects of alcohols on combustion processes and emissions.
Article
Energy & Fuels
Chinonso Ezenwajiaku, Midhat Talibi, Ramanarayanan Balachandran
Summary: This study focuses on the formation and growth characteristics of polycyclic aromatic hydrocarbons (PAHs) in inverse diffusion flames of various hydrocarbon fuels enriched with H-2. The results show that only the addition of H-2 to CH4 significantly reduces PAH concentrations as the flame length increases. Additionally, the growth rate of PAHs remains relatively stable regardless of the fuel bonding, molecular structure, and H:C ratio.
Article
Chemistry, Physical
Nathan A. Mahynski, Harold W. Hatch, Matthew Witman, David A. Sheen, Jeffrey R. Errington, Vincent K. Shen
Summary: By combining statistical mechanical principles with biased sampling techniques, it is possible to predict the thermodynamic properties of systems more accurately and achieve precise estimates across a wide range of conditions. These extrapolations significantly increase the amount of accurate information that can be extracted from simulations, providing data for data-intensive algorithms.
MOLECULAR SIMULATION
(2021)
Article
Thermodynamics
Hossein Janbazi, Christof Schulz, Irenaus Wlokas, Hai Wang, Sebastian Peukert
Summary: This paper investigates the thermochemical properties of Si-C-H radicals and molecules in silicon-organic compounds through quantum-chemical calculations and isodesmic reaction schemes, providing group additivity values. By revising stable Si-C-H species data, refining GAVs, and deriving GAVs for Si-C-H containing radicals, this study offers a detailed analysis of the influence of Si-C-H species in flame chemistry.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Kevin Wan, Xian Shi, Hai Wang
Summary: This study modeled the electronic and optical properties of flame-generated carbon nanoparticles, analyzing the ionization energies and optical band gaps of particles of different sizes. It found a dependence of the refractive index on particle size, with the imaginary component being particularly sensitive. The study highlights the importance of considering size effects in refractive index for laser diagnostics of soot in flames.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Jackson Crane, Xian Shi, Jonathan T. Lipkowicz, Andreas M. Kempf, Hai Wang
Summary: A geometric model with low computational complexity is proposed to simulate detonation behavior in physical systems. Based on 1D simulations in hydrogen-oxygen mixtures, a detonation cell stabilization mechanism is identified, which relies on the gap between pressure and temperature fronts. Serial analysis of blasts leads to a unique stable blast kernel size for any mixture.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Gianluigi De Falco, Giancarlo Mattiello, Mario Commodo, Patrizia Minutolo, Xian Shi, Andrea D'Anna, Hai Wang
Summary: This study determines the electronic band gap of flame-formed carbon nanoparticles for the first time using scanning tunneling spectroscopy, showing a clear size-dependency and matching results within experimental uncertainty with optical band gap measurements. The absence of over potential in CNP samples compared to PAH samples may indicate stronger intermolecular interactions among the PAHs in CNPs.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Nanoscience & Nanotechnology
Chris J. Peacock, Connor Lamont, David A. Sheen, Vincent K. Shen, Laurent Kreplak, John P. Frampton
Summary: By studying the pairwise mixing behavior of 68 water-soluble compounds and using machine learning classifiers to predict their miscibility, the random forest classifier emerged as the most successful with high levels of accuracy, specificity, and sensitivity under different scenarios. The potential of this machine learning approach to improve the design of screening experiments for aqueous two-phase systems for various scientific and industrial applications was demonstrated.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Thermodynamics
Kun Wang, Rui Xu, Craig T. Bowman, Hai Wang
Summary: Flow reactors are commonly used for investigating the pyrolysis and oxidation chemistry of fuels, with either electrical heaters or vitiation heaters providing energy. This study examines the impact of vitiation on flow reactor studies of fuel combustion chemistry, finding that vitiation decreases reaction time scales but does not significantly affect product yields at fixed fuel conversion rates.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Rui Xu, Hai Wang
Summary: The HyChem approach combines lumped reaction steps with detailed chemistry for predicting high-temperature combustion of real fuels. The accuracy of HyChem model predictions depends on the availability and accuracy of speciation data. Results show that speciation data are necessary for reliable predictions of laminar flame speed and ignition delay time at temperatures above 1200 K.
COMBUSTION AND FLAME
(2021)
Biographical-Item
Thermodynamics
Katharina Kohse-Hoinghaus, Hai Wang
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Physical
Paolo Fortugno, Stanislav Musikhin, Xian Shi, Hai Wang, Hartmut Wiggers, Christof Schulz
Summary: In this study, the role of oxygen in gas-phase synthesis of graphene in atmospheric hydrocarbon-fed microwave plasmas was systematically investigated. It was found that ethanol resulted in the formation of pure few-layer graphene, while ethylene produced a mixture of carbon allotropes. The addition of water or reduction of ethylene flow rate promoted the formation of graphene.
Article
Thermodynamics
Stefano Veronesi, Mario Commodo, Luca Basta, Gianluigi De Falco, Patrizia Minutolo, Nikolaos Kateris, Hai Wang, Andrea D'Anna, Stefan Heun
Summary: In this study, the morphological and electronic properties of incipient soot particles formed during combustion were investigated using STM and STS techniques. The results revealed the size and semiconductor behavior of the incipient soot particles.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Jackson Crane, Xian Shi, Rui Xu, Hai Wang
Summary: The study found that natural gas has significantly smaller detonation induction length and lower detonation pressure limit compared to high purity methane, suggesting a wider operating range when used as a fuel in detonation-based engines. Additionally, the variability in detonation and combustion behaviors between natural gases and commercial methane is expected to be similar, highlighting the importance of using natural gas in safety-related studies instead of neat methane.
COMBUSTION AND FLAME
(2022)
Article
Multidisciplinary Sciences
Qi Zheng, Xian Shi, Jinyang Jiang, Haiyan Mao, Nicholas Montes, Nikolaos Kateris, Jeffrey A. Reimer, Hai Wang, Haimei Zheng
Summary: This study investigates the influences of small sizes and defects on cubic diamond nanostructures using transmission electron microscopy, electron diffraction, multislice simulations, and other techniques. The experimental and simulation results reveal that cubic nanodiamonds smaller than 5 nm and with defects can display forbidden reflections, providing insights into the structural complexity and the impact of defects on nanodiamond structures.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Medicine, General & Internal
Kexue Deng, Lu Wang, Yuchan Liu, Xin Li, Qiuyang Hou, Mulan Cao, Nathan Norton Ng, Huan Wang, Huanhuan Chen, Kristen W. Yeom, Mingfang Zhao, Ning Wu, Peng Gao, Jingyun Shi, Zaiyi Liu, Weimin Li, Jie Tian, Jiangdian Song
Summary: A deep learning-based system was developed and validated to predict the survival benefits of EGFR-TKIs and ICIs in stage IV NSCLC patients using pre-therapy CT images, facilitating optimized and individualized treatment strategies.
Article
Chemistry, Analytical
Evan P. Jahrman, Lee L. Yu, William P. Krekelberg, David A. Sheen, Thomas C. Allison, John L. Molloy
Summary: The speciation of arsenic plays a crucial role in its toxicity and bioavailability. This study explores the use of X-ray spectroscopies to determine arsenic speciation profiles in materials related to public health initiatives, such as food safety. The results provide insights into the efficacy of X-ray spectroscopy and the accuracy of analysis. The study also introduces the lasso regression method to improve the statistical inferences and reduce overfitting.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2022)
Article
Thermodynamics
Yifan Yang, Haodong Zhang, Linye Li, Mingming Gu, Xi Xia, Fei Qi
Summary: This paper investigates the formation of a blue whirl by controlling tangential and radial airflows. By using a unique fire whirl apparatus, the blue whirl can be formed directly upon ignition without going through the transient phase. The study also discovers new flame regimes and explores the mechanism behind the formation and transition of the blue whirl.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Xiaobin Qi, Songyan Gao, Zhiping Zhu, Qinggang Lyu, Haixia Zhang
Summary: This study experimentally investigated the propagation characteristics of reverse combustion under oxygen-limited and enriched conditions. The contribution of volatiles gas-phase oxidation and char surface oxidation to reverse combustion was evaluated. The results showed that oxygen enrichment expanded the operating range of oxygen flow rate for reverse combustion and enhanced the low-temperature oxidation of the solid fuel. The findings provide a better understanding of the driving mechanism of reverse combustion and have important implications for efficient thermal conversion of solid fuels.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Bingjie Chen, Peng Liu, Bingzhi Liu, Zhandong Wang, Xiang Gao, William L. Roberts
Summary: In this study, the low temperature oxidation of 1,2,4-trimethylbenzene was investigated using experiments and numerical simulations. The results showed the presence of toxic oxygenated aromatic compounds and proposed potential formation pathways. The numerical simulations accurately predicted the mole fractions of most compounds, but some compounds were missing.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Meng Sui, Zhiheng Zhu, Fashe Li, Hua Wang
Summary: The effect of adding ferrocene as a combustion catalyst to Jatropha biodiesel on its pyrolysis and combustion performance is investigated. The results show that adding ferrocene reduces activation energy and harmful emissions while improving combustion efficiency.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Manaf Sheyyab, Mohammed Abdulrahman, Subharaj Hossain, Patrick T. Lynch, Eric K. Mayhew, Kenneth Brezinsky
Summary: Fuel surrogates, simplified representations of complex fuels, accurately model speciation results and reaction kinetics, reproduce the ignition quality and chemical functional group compositions of their parent fuels.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Yan Wang, Shumeng Xie, Hannes Bottler, Yiqing Wang, Xinyi Chen, Arne Scholtissek, Christian Hasse, Zheng Chen
Summary: This study investigates how flow affects the ignition and transition process of a cool flame. The results show that the ignition energy determines the highest temperature and the strain rate influences the flame propagation and the transition from cool flame to hot flame.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Tanusree Chatterjee, Mengyuan Wang, Goutham Kukkadapu, Chih-Jen Sung, William J. Pitz
Summary: Cycloalkanes, including cyclohexane, are important hydrocarbons in transportation fuels. However, limited oxidation data at low-to-intermediate temperatures and inadequate predictive ability of kinetic models have hindered the understanding and improvement of cyclohexane oxidation. This study provides experimental and modeling results to develop a more accurate kinetic model for cyclohexane oxidation.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Tao Wu, Erik Hagen, Haiyang Wang, Dylan J. Kline, Michael R. Zachariah, Carole Rossi
Summary: It was found that incorporating CuO into Al/I2O5 can significantly reduce the ignition time and enhance the combustion performance. The optimum composition of 80/20 wt% of I2O5/CuO shows a 30 times shorter ignition time and produces a peak pressure and pressurization rate 4 and 26 times greater than traditional Al/I2O5. A series of characterizations helped unravel the cause of improvement and propose a reaction mechanism for this ternary Al/I2O5/CuO system. This study proposes a facile, inexpensive, and efficient way to enhance the combustion performance of Al/I2O5 biocidal nanoenergetic materials.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Mahmoud Gadalla, Shervin Karimkashi, Islam Kabil, Ossi Kaario, Tianfeng Lu, Ville Vuorinen
Summary: In this study, the flame initiation process in dual-fuel spray assisted combustion is explored through scale-resolved simulations, providing numerical evidence on the initiation of premixed flames. It is found that there is a transient mixed-mode combustion phase after ignition, followed by a primarily deflagrative combustion mode. The interactions between turbulence and premixed flame front are characterized in the corrugated regime.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Neeraj Kumar Pradhan, Arindrajit Chowdhury, Debasis Chakraborty, Neeraj Kumbhakarna
Summary: In this study, a modified model for predicting the burn rate of composite solid propellants is proposed. The model has been validated against experimental and theoretical results, and it outperforms existing models in all cases considered. The model is highly robust and provides results quickly, making it highly efficient in terms of time, effort, and computational resources.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Lili Ye, Zhihe Zhang, Fan Wang, Xiaodong Wang, Yiming Lu, Lei Zhang
Summary: This study investigated the pyrolysis mechanism of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) explosive using ab initio and kinetic modeling simulations. The results showed that N-NO2 bond fission and C-H beta-scission are important channels in the decomposition of HMX.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Andrei N. Lipatnikov, Hsuchew Lee, Peng Dai, Minping Wan, Vladimir A. Sabelnikov
Summary: This study investigates the importance of thermodiffusive and hydrodynamic instabilities of laminar flames in turbulent flows through numerical simulations. The analysis suggests that laminar flame instabilities play a minor role at sufficiently high Karlovitz numbers.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Shijie Xu, Yue Qiu, Leilei Xu, Jianqing Huang, Shen Li, Elna J. K. Nilsson, Zhongshan Li, Weiwei Cai, Marcus Alden, Xue-Song Bai
Summary: Metal powder is a promising carbon-free and recyclable energy carrier. In this study, a computational model for the combustion and phase change of micron-sized iron particles was proposed and validated. The model successfully captures the melting, surface reactions, cooling, and solidification processes. The study also reveals a two-stage solidification phenomenon and identifies a diffusion-controlled mechanism during the melting process. The reaction between iron and CH4/O2/N2 flame products is found to play a significant role in the iron combustion process.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Khalid Aljohani, Abd El-Sabor Mohamed, Haitao Lu, Henry J. Curran, S. Mani Sarathy, Aamir Farooq
Summary: This study investigates the impact of exhaust gas recirculation (EGR) and NOx on the ignition delay time of oxygenated gasoline. A gasoline surrogate model is developed and the experimental data are useful for predicting fuel ignition behavior in internal combustion engines. The results show that EGR inhibits gasoline reactivity, while NOx has a promoting effect at high temperatures. This research is important for understanding the combustion behavior of gasoline in engines.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Chengcheng Ao, Jia Yan, Tong Yan, Lidong Zhang, Pan Wang
Summary: This study investigates the inhibitory effect of ammonia blended with hydrocarbon fuels on soot formation. The results show that there is a chemical interaction between ammonia and polycyclic aromatic hydrocarbons (PAHs), blocking the formation of larger PAHs.
COMBUSTION AND FLAME
(2024)
