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
Changfa Tao, Bin Liu, Yuling Dou, Yejian Qian, Yu Zhang, Shun Meng
Summary: The study examined the flame height and lift-off height of a turbulent jet diffusion flame under different conditions. Experimental results showed that the flame height initially increased and then decreased with an increase in CO2 concentration, while the lift-off height increased with CO2 concentration.
Article
Thermodynamics
Francisco Cepeda, Luke Di Liddo, Marek Serwin, Ahmet E. Karatas, Seth B. Dworkin
Summary: This study investigates the effects of adding oxygen to laminar co-flow DME diffusion flames, and reveals a reversal phenomenon in soot production. The chemical effects of adding oxygen are found to be more important than the thermal and dilution effects. It is concluded that the reversal occurs when nearly all DME disassociated before exiting the fuel tube, indicating a sudden transition from a partially premixed DME flame to one which primarily burns C1 fuel fragments. This study provides important insights into the control mechanisms of soot production in DME combustion.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
M. A. Ashraf, H. A. Ahmed, S. Steinmetz, M. J. Dunn, A. R. Masri
Summary: The experimental investigation in an axisymmetric ethylene laminar coflow diffusion flame showed that increasing the oxygen concentration in the oxidizer stream leads to an increase in precursor nanoparticles and structural growth in these nanoparticles. The study also found similarities in particle evolution and a shift in structural transformation from aliphatic to aromatic features with increasing coflow oxygen concentration. The soot volume fraction and primary soot particle diameter increase with coflow oxygen enrichment up to a threshold, beyond which they decrease.
Article
Thermodynamics
Yiqing Wang, Wang Han, Antonio Attili, Zheng Chen
Summary: This study investigates the impact of soot formation on flame speed measurements under fuel-rich conditions by simulating one-dimensional outwardly propagating spherical flames. The results show that soot dynamics and morphology are highly sensitive to changes in equivalence ratio and flame radius.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Applied
Xiaokang Nie, Jiawei Qi, Shunjie Feng, Ya Liu, Bingbing Qiu, Huaqiang Chu
Summary: In this study, the mixture of n-heptane and toluene was used as a surrogate fuel for diesel. The flame morphology, particle size, and soot deposition of three kinds of fuel blends were investigated using various microscopy techniques. The results showed that the addition of toluene promoted the formation of soot and influenced its morphology and structure.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Applied
Xiaokang Nie, Jiawei Qi, Shunjie Feng, Ya Liu, Bingbing Qiu, Huaqiang Chu
Summary: This study investigated the particle size, nanostructure, microcrystalline size, and soot deposition morphology of three different fuel laminar diffusion flames of n-heptane and toluene blends using TEM, HRTEM, XRD, and FESEM. Results showed that with an increase in toluene content, flame height increased, temperature decreased, PAH content increased, promoting soot formation with larger particle size. Additionally, the graphitization degree of soot increased with toluene content, leading to larger fringe length and microcrystalline width.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Energy & Fuels
Yang Liu, Yishu Xu, Kai Zhang, Pu Zhang, Xiaobei Cheng
Summary: In this study, the effects of NH3 addition on the morphology and nanostructures of soot particles in ethylene co-flow diffusion flames were investigated. The results showed that NH3 addition resulted in changes in flame height and temperature, as well as a decrease in the size and number of soot particles. The investigation of soot nanostructures indicated that NH3 delayed the process of particle inception and surface growth.
Article
Energy & Fuels
Shunjie Feng, Run Hong, Jiawei Qi, Wenlong Dong, Bingbing Qiu, Xianyao Yan, Huaqiang Chu
Summary: The influence of ammonia on the morphology of soot and the evolution of nanoparticle structure in the laminar flame of ethylene was studied. The experimental results showed that the addition of ammonia can inhibit the growth of soot nuclei and delay the formation of incipient soot, and has different effects on the evolution of soot morphology and structure in the ethylene flame. The main reason may be the chemical and thermal effects of ammonia on the nanostructure and morphology of soot at different stages of soot formation.
Article
Crystallography
Hiroshi Sakurai, Naruki Tsuji, Yoshio Zama, Kosuke Suzuki, Kazushi Hoshi, Daisuke Hiramoto, Yoshiharu Sakurai, Tomohiko Furuhata
Summary: X-ray Compton scattering was used to measure the temperature distribution and chemical state distribution of a laminar diffusion flame, showing its potential as a novel nondestructive measurement method for temperature and chemical states in combustion reactions.
Article
Energy & Fuels
Yang Liu, Xiaobei Cheng, Yuchen Ya, Bowen Wang, Pu Zhang, Kai Zhang, Yishu Xu
Summary: This study specifically investigates the impact of PODE3 addition on soot, and the results show that PODE3 substitution can reduce the soot generation region, increase flame temperatures, and improve the oxidation reactivity of soot particles.
Article
Thermodynamics
Yuling Dou, Haiqiang Liu, Bin Liu, Yu Zhang, Yongqiang Liu, Xiaozhang Cheng, Changfa Tao
Summary: The study investigated the flame radiation fraction of a turbulent jet diffusion flame of propane and carbon dioxide mixed gas with different nozzle diameters. The results indicated that the flame radiation fraction decreases with increasing carbon dioxide concentration for a given heat release rate. Theories of soot formation and laminar flame speed were used to explain the variation in radiation fraction under different volume fractions of carbon dioxide.
Article
Thermodynamics
Felipe Escudero, Juan J. Cruz, Ignacio Verdugo, Nicolas Gutierrez, Fengshan Liu, Jerome Yon, Andres Fuentes
Summary: The auto-compensating laser-induced incandescence (AC-LII) technique is commonly used to measure soot volume fraction (fv) in flames. This study proposes a correction to the AC-LII measured fv based on the soot maturity coefficient β and absorption function E(m,λ) in a laminar coflow ethylene diffusion flame. The corrected AC-LII results are in good agreement with those measured by MW-LOSA/EMI. Rating: 9 points
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Abhee Singh, Nicholas Tsolas
Summary: Recent advancements in metabolic engineering have shown that isopropanol-butanol-ethanol (IBE) can be produced cost-effectively from switchgrass biomass. This makes IBE a promising fuel for the future, allowing for a transition to renewable biofuels in the transportation sector. Experimental measurements and numerical modeling studies were conducted to examine the sooting tendency of IBE when blended with a diesel surrogate. The results showed that increasing the IBE content led to a decrease in soot formation and suggested potential mechanisms for reducing soot through the perturbation of reaction intermediates and the augmentation of oxidation reactions.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Peng Liu, Hafiz Ahmad, Xuesong Jiang, Hongyu Chen, Yan Lin, Bowen Mei, Yuyang Li
Summary: This study investigated the structure and oxidation reactivity of soot sampled from an ethylene flame, showing that residence time is crucial in modifying surface functional groups and that as soot matures, the oxidation reaction transitions into a unimodal process.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Jorge Contreras, Jean-Louis Consalvi, Andres Fuentes
COMBUSTION AND FLAME
(2018)
Article
Thermodynamics
N. Hernandez, A. Fuentes, J. L. Consalvi, J. C. Elicer-Cortes
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2018)
Article
Thermodynamics
N. Hernandez, A. Fuentes, P. Reszka, A. C. Fernandez-Pello
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2019)
Article
Thermodynamics
J. Yon, F. Liu, J. Moran, A. Fuentes
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2019)
Article
Energy & Fuels
D. Cortes, J. Moran, F. Liu, F. Escudero, J. -L. Consalvi, A. Fuentes
Article
Energy & Fuels
A. Jerez, J. J. Cruz Villanueva, L. F. Figueira da Silva, R. Demarco, A. Fuentes
Article
Computer Science, Interdisciplinary Applications
J. Moran, A. Fuentes, F. Liu, J. Yon
COMPUTER PHYSICS COMMUNICATIONS
(2019)
Article
Thermodynamics
J. J. Cruz, Luis Fernando Figueira da Silva, F. Escudero, F. Cepeda, J. C. Elicer-Cortes, A. Fuentes
Summary: A multi-wavelength pyrometry method is developed to evaluate soot temperature for laminar axisymmetric non-premixed flames. The method combines a single radiative model with three detection wavelengths to increase the accuracy of soot temperature determination. The method is robust and reliable, and can evaluate soot temperature without the need for additional measurements of the soot absorption coefficient.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Thermodynamics
F. Escudero, J. J. Cruz, F. Liu, A. Fuentes
Summary: This work introduces a novel method to correct the trapping effect of laser-induced incandescence (LII) signals inside flames, aiming to obtain soot volume fraction distributions. The method is validated in 2D and 3D flames, demonstrating the importance of considering signal trapping in measurements of soot volume fraction.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Agricultural Engineering
Tito Andre Arevalo-Ramirez, Andres Hernan Fuentes Castillo, Pedro Sebastian Reszka Cabello, Fernando A. Auat Cheein
Summary: Vegetation indices can be used to assess vegetation cover quantitatively and qualitatively by predicting biophysical properties of leaves through their reflectance features. Different indices can describe the same biophysical parameter, with at least sixteen indices capable of inferring vegetation water content. A machine learning regressor can predict leaf reflectance at specific spectral bands using leaf moisture content and a single vegetation index.
BIOSYSTEMS ENGINEERING
(2021)
Article
Chemistry, Physical
Yabei Xu, Hongyu Wang, Xiaoya Chang, Andres Fuentes, Rodrigo Demarco, Dongping Chen
Summary: The introduction of functional groups at high coverage levels can significantly influence the band structures of polycyclic aromatic hydrocarbon (PAH) clusters. The HOMO-LUMO gaps are highly sensitive to the type and distribution of functional groups. This study proposes an in-house method to build PAH clusters with surface functionalization of -OH, -COOH, and -CHO groups using the DFT method. It is found that the -CHO groups have the greatest impact in reducing the gap value, though exceptions exist due to the spatial distribution of functional groups. PAH clusters with oxygenated functions still exhibit characteristics of an indirect band gap material. The coupling effect of PAH stacking and PAH size on band structures is also discussed.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Thermodynamics
Maria Thomsen, Juan Jose Cruz, Felipe Escudero, Andres Fuentes, Carlos Fernandez-Pello, Michael Gollner, David L. Urban, Gary A. Ruff
Summary: The spread of fire inside a spacecraft is a constant concern for space travel. This study aims to understand the combustion processes in microgravity and investigate the role of thermal radiation in flame spread. The experiments conducted as part of the NASA project Saffire IV provide valuable data and insights for future space facilities' fire safety.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Felipe Escudero, Juan J. Cruz, Ignacio Verdugo, Nicolas Gutierrez, Fengshan Liu, Jerome Yon, Andres Fuentes
Summary: The auto-compensating laser-induced incandescence (AC-LII) technique is commonly used to measure soot volume fraction (fv) in flames. This study proposes a correction to the AC-LII measured fv based on the soot maturity coefficient β and absorption function E(m,λ) in a laminar coflow ethylene diffusion flame. The corrected AC-LII results are in good agreement with those measured by MW-LOSA/EMI. Rating: 9 points
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Jose Ignacio Rivera, Fernando Ebensperger, Francisco Valenzuela, Leonardo Escandar, Pedro Reszka, Andres Fuentes
Summary: This study investigates the role of fire retardant treatments on the discontinuous ignition of wildland fuels through theoretical and experimental research. The research finds that an increase in the concentration of fire retardant delays the ignition time. The fire retardant modifies the thermophysical properties of the fuel bed, resulting in a delayed thermal response while the critical heat flux remains unchanged. The study provides valuable insights for forest services worldwide on the optimal concentrations and delivery methods of fire retardants during wildfire response. © 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Civil
Carlos Alvarez, Gabriela Moreno, Francisco Valenzuela, Jose Ignacio Rivera, Fernando Ebensperger, Pedro Reszka, Andres Fuentes
Summary: The Idealized-Firebrand Ignition Test (I-FIT) protocol was used to evaluate the piloted ignition delay times of fuel beds composed of leaves of Eucalyptus globulus. A theoretical model based on thermal ignition theory was developed to describe the heating and ignition of the fuel beds. The model accurately predicts the ignition delay time for different fuel layer sizes, but shows poorer accuracy for temperature evolution.
FIRE SAFETY JOURNAL
(2023)
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)