Combustion and Flame最新文献

{"title":"An experimental and kinetic study of quadricyclane autoignition at high temperatures","authors":"Yuting Ye ,&nbsp;Jianbing Cai ,&nbsp;Wenbin Tang ,&nbsp;Yiwei Li ,&nbsp;Dongxian Li ,&nbsp;Xu Li ,&nbsp;Meng Xu ,&nbsp;Changhua Zhang ,&nbsp;Jijun Zou ,&nbsp;Chuanfeng Yue ,&nbsp;Jingbo Wang","doi":"10.1016/j.combustflame.2024.113813","DOIUrl":"10.1016/j.combustflame.2024.113813","url":null,"abstract":"<div><div>Quadricyclane, with high density and net heat value, can provide more energy to extend the flight distance and enhance the payload capacity of aircraft. The autoignition characteristics of quadricyclane have been investigated behind reflected shock waves in this study. With argon as the diluent gas, experiments are conducted at pressures of 2, 4, and 10 atm, equivalence ratios of 0.5, 1.0, and 2.0, fuel concentrations of 0.2% and 0.4%, and temperatures ranging from 1276 to 1773 K. The results indicate that the ignition delay time decreases with increasing pressure and fuel concentration, and increases with increasing equivalence ratio, showing a strong positive dependence with the equivalence ratio. Regression analysis of the experimental data has yielded quantitative relationships. To clarify the combustion process, a high-temperature kinetic model based on the NUIGMech1.1 mechanism has been developed, and the validation demonstrates that the model can accurately describe the autoignition characteristics of quadricyclane. Sensitivity and reaction pathways analyses have been conducted, the results reveal that quadricyclane primarily undergoes ring-opening isomerization to produce 2,5-norbornadiene at high temperature. Furthermore, to demonstrate the effect of the strained structure on fuel ignition, the ignition delay times of quadricyclane/air mixture are measured within a temperature range from 952 to 1113 K, pressure of 10 atm, and equivalence ratio of 1.0. When compared with the ignition delay times of JP-10 and Jet A, quadricyclane exhibits the shortest ignition delay time due to its exothermic ring-opening reaction occurring at the initial stage.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113813"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial distribution and temporal evolution of wall-stabilized DME/O2 premixed cool flames","authors":"Meng Zhou ,&nbsp;Minhyeok Lee ,&nbsp;Yiguang Ju ,&nbsp;Yuji Suzuki","doi":"10.1016/j.combustflame.2024.113814","DOIUrl":"10.1016/j.combustflame.2024.113814","url":null,"abstract":"<div><div>The low-temperature oxidation of dimethyl ether (DME) was investigated in premixed wall-stabilized cool flames at two equivalence ratios (<em>ϕ</em>) of 0.2 and 0.5. Using a time-of-flight mass spectrometry (TOF-MS) coupled with gas chromatography (GC), the spatial distributions of major intermediate species, including DME, CH₂O (formaldehyde), CO, CO₂, and CH₃OCHO (methyl formate), were quantified under well-controlled boundary conditions. Moreover, the temporal evolutions of multiple intermediate species in the wall-stabilized cool flame ignition process were measured via TOF-MS, while the wall temperature was gradually ramped up from 550 K to 730 K. Several kinetic models were examined herein to assess the estimated low-temperature reactivity of DME by comparing the one-dimensional axisymmetric simulation results with the experimental data. Wall-stabilized cool flame structures at equivalence ratios <em>ϕ</em> of 0.2 and 0.5 were quantitatively examined with the major intermediate species. It is found that the kinetic models reasonably predict the onset of the reaction zone near the wall. Among these models, Kurimoto et al.’s model gives better predictions for the distributions of CH₂O and CO, which are characteristic species of cool flames. In addition, time-resolved measurements of the unsteady cool flames identified the negative temperature coefficient (NTC) turnover points for different species across various temperature regions. It is also found that the Kurimoto et al. model still indicates a slightly higher reactivity of DME in the low-temperature range, resulting in earlier DME consumption and a shift of NTC window to lower temperatures at <em>ϕ</em> = 0.2.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113814"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Premixed flame behaviors of H2/CH4/C3H8 mixtures in a narrow-gap disk burner and effective Lewis numbers","authors":"Sang Min Lee,&nbsp;Nam Il Kim","doi":"10.1016/j.combustflame.2024.113799","DOIUrl":"10.1016/j.combustflame.2024.113799","url":null,"abstract":"<div><div>Hydrogen combustion is receiving significant interest as a carbon-free energy resource. However, the distinctive combustion characteristics of hydrogen have yet to be explored sufficiently. This study experimentally investigated the effects of hydrogen blending with methane and propane using a narrow-gap disk burner (NGDB). Three representative flame characteristics were considered: the quenching distance, the flame propagation velocity, and the number of cellular structures. It was confirmed that the quenching Peclet number and the number of cellular structures were significantly affected by the addition of hydrogen, primarily due to the Lewis number. However, defining the Lewis number was somewhat ambiguous, especially for multi-component fuel mixtures. Although various effective Lewis numbers have been suggested, their reliability must be adequately assessed. Six representative Lewis numbers were evaluated based on previous studies, and their correlations with flame characteristics were discussed. Conclusively, the previous Lewis numbers were only partly acceptable and had some exceptions. Therefore, a revised effective Lewis number for the hydrogen-blended flames was suggested, using the maximum laminar burning velocity as a new criterion for determining the deficient species, which showed improved correlations with representative flame propagation characteristics.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113799"},"PeriodicalIF":5.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing the oxidation kinetics of n-dodecane, ethylcyclohexane and n-butylbenzene blended fuels","authors":"Meirong Zeng ,&nbsp;Jigang Gao ,&nbsp;Yuwen Deng ,&nbsp;Peiqi Liu ,&nbsp;Zhongyue Zhou ,&nbsp;Jiuzhong Yang ,&nbsp;Wenhao Yuan ,&nbsp;Fei Qi","doi":"10.1016/j.combustflame.2024.113806","DOIUrl":"10.1016/j.combustflame.2024.113806","url":null,"abstract":"<div><div>The oxidation chemistry of single component has been widely explored, which motivates us to investigate the oxidation chemistry of blended fuels. Here, <em>n</em>-dodecane, ethylcyclohexane and <em>n</em>-butylbenzene have been selected as fuel components for representing <em>n</em>-alkane, cyclic alkane and aromatic, respectively. The oxidation experiments of blended <em>n</em>-dodecane, ethylcyclohexane and <em>n</em>-butylbenzene fuels were performed in an atmospheric jet stirred reactor, temperatures ranging from 450 to 850 K, equivalence ratios of 0.5 and 1.0. The synchrotron vacuum ultraviolet radiation photoionization mass spectrometry was applied to measure the featured intermediates, such as hydroperoxides and highly oxygenated molecules (HOMs) with characteristic functional groups. Subsequently, a kinetic model for the blended fuels was developed and validated, which was used to reveal the crucial coupled oxidation chemistry that drives the global oxidation reactivity and products distribution. It is revealed that the active chain initiators, such as OH radicals, produced by the oxidation reactions of <em>n</em>-dodecane and ethylcyclohexane, significantly enhance the oxidation reactivity of <em>n</em>-butylbenzene. Furthermore, the hydroperoxides and ketohydroperoxides, acting as key experimental evidence for the existence of first O₂ addition and second O₂ addition, contribute to the formation of active chain initiators, such as OH radicals. This work extends the existing conceptual reaction schemes proposed for the oxidation of single fuel towards the coupled oxidation chemistry of blended fuels. This, in turn, improves our understanding towards the complicated oxidation chemistry of real fuels.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113806"},"PeriodicalIF":5.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrolysis and kinetic modeling investigation of 1-methoxy-2-propanol","authors":"Zhi-Min Wang ,&nbsp;Du Wang ,&nbsp;Ahmed E. Mansy ,&nbsp;Zhen-Yu Tian","doi":"10.1016/j.combustflame.2024.113804","DOIUrl":"10.1016/j.combustflame.2024.113804","url":null,"abstract":"&lt;div&gt;&lt;div&gt;1-Methoxy-2-propanol (PM, CC(O)COC) is a simple and representative hydroxyl ether that has gained attention as an alternative biofuel. In this study, the pyrolysis of PM was investigated in an atmospheric pressure flow reactor within the temperature range of 573 to 1173 K. Gas chromatographs were utilized to detect the species produced during the pyrolysis experiment. Acetaldehyde, &lt;em&gt;n&lt;/em&gt;-butene, &lt;em&gt;i&lt;/em&gt;-butene, and acetone were newly identified among the eighteen products and intermediates in PM pyrolysis. &lt;em&gt;Ab initio&lt;/em&gt; calculations were employed to investigate the potential energy surface and pressure-dependent rate coefficients of PM unimolecular decomposition. The energetically favored channel for unimolecular initiation reactions is found to be H&lt;sub&gt;2&lt;/sub&gt;O elimination. Based on the bond dissociation energies of PM, a detailed kinetic model consisting of 608 species and 3160 reactions was proposed with reasonable predictions against the experimental results. Rate-of-production analysis reveals that the consumption of PM is mainly controlled by H-abstractions involving H and CH&lt;sub&gt;3&lt;/sub&gt; radicals at three different carbon sites to generate radicals C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;-1, C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;-2 and C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;9&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;-3, respectively. At 1023 K, the conversion rate of PM reaches around 75%, and the reaction 2CH&lt;sub&gt;3&lt;/sub&gt; (+M) = C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt; (+M) exhibits the greatest inhibition effect, while the reaction C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;10&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;=C&lt;sub&gt;3&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;OH2-1+CH&lt;sub&gt;3&lt;/sub&gt;O has the greatest promotion effect on PM consumptions. The results contribute to better understand the pyrolysis behavior, enhancing the utilization of PM as a sustainable energy source.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Novelty and significance statement&lt;/h3&gt;&lt;div&gt;1-Methoxy-2-propanol (PM) is an alternative biofuel, yet there is a significant lack of research exploring its kinetic behavior. The novelty of this work focuses on the atmospheric-pressure pyrolysis of PM. The PM pyrolysis experiments were carried out with newly detected intermediates and products involved in the process. To further enhance the understanding of PM kinetic behavior, a new kinetic model consisting of 608 species and 3160 reactions was developed. This model was utilized to predict the mole fractions of PM, H&lt;sub&gt;2&lt;/sub&gt;, CO and important intermediates and products during the pyrolysis process. Additionally, the ROP and analyses were conducted to shed light on the reaction routes. Before this work, there was a lack of comprehensive investigation into the kinetics of PM pyrolysis, making this study significant in bridging the knowledge gap in this field. The findings of this investigation not only contribute to our understanding of PM pyrolysis kinetics but also serve as a foundation for further exploration of oxygenated additives fuel. By elucidating the mechanisms and pathways involved in the pyro","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113804"},"PeriodicalIF":5.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An experimental and kinetic modeling study on the ignition property of an alternative gas to liquid jet fuel","authors":"Quan-De Wang ,&nbsp;Bi-Yao Wang ,&nbsp;Qian Yao ,&nbsp;Jinhu Liang ,&nbsp;Ping Zeng ,&nbsp;Jian-Gang Liu ,&nbsp;Zu-Xi Xia","doi":"10.1016/j.combustflame.2024.113805","DOIUrl":"10.1016/j.combustflame.2024.113805","url":null,"abstract":"<div><div>Alternative jet fuel from Fischer-Tropsch (FT) synthesis represents an important kind of aviation fuel in the near future. However, the combustion properties of FT jet fuel have not been fully explored yet. Herein, this work reports an experimental and kinetic modeling study on the ignition characteristics of a coal-derived FT jet fuel. To facilitate its usage as a “drop-in” fuel in current aircraft and infrastructure, a blended fuel of the present FT fuel with a traditional RP-3 jet fuel with relatively high aromatic hydrocarbons is also prepared and studied. Specifically, a shock tube facility is employed to measure the ignition delay times (IDTs) of the FT, RP-3, and the blended jet fuels under the combustion conditions, i.e., temperature ranging from 1000–1800 K, pressure at 3 and 10 bar, equivalence ratio at 0.5, 1.0, and 2.0. Two-dimensional gas chromatography (GC × GC) analysis is adopted to determine the chemical compositions of the FT and RP-3 jet fuels, which is then used to aid the development of surrogate models. Most importantly, the contemporary combustion chemical kinetic mechanism via detailed generation, automatic generation, lumping, decoupling and HyChem methods are employed to model the IDTs, and the mechanism reproducibility of these mechanisms are systematically compared. The present work should be valuable to understand the chemical structure effect on alternative jet fuels and also provides important information for the development of different kinds of combustion kinetic mechanisms.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113805"},"PeriodicalIF":5.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ignition and combustion properties of NGO coated AlH3","authors":"Xiaoyong Ding ,&nbsp;Yitong Fang ,&nbsp;Siqi Wang ,&nbsp;Yao Zhou ,&nbsp;Qiangqiang Liu ,&nbsp;Yingle Liu ,&nbsp;Ning Liu","doi":"10.1016/j.combustflame.2024.113802","DOIUrl":"10.1016/j.combustflame.2024.113802","url":null,"abstract":"<div><div>AlH₃ is a highly promising additive for energetic materials and has gained considerable attention as a substitute fuel for aluminum in solid propellants. In order to improve its compatibility with energetic materials and oxidants, carbon coating materials are often used. Nitrated graphene oxide (NGO) was prepared and used as a surface modifier of <em>α</em>-AlH₃ in our study. Various analytical techniques were utilized to examine its structure and morphology, including Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), particle size distribution (PSD) and X-ray diffraction (XRD). The oxidization, ignition characteristics, flame propagation behavior and heat of combustion of AlH₃ and AlH₃/NGO powder were investigated using differential thermal analysis (DTA), a laser igniter, a high-speed camera and an oxygen bomb calorimetry. Results show that NGO coating agent catalyzes the thermal decomposition and hydrogenation process of AlH₃, and accelerates the oxidation process of AlH₃. The addition of 4 % NGO decreases the oxidation activation energy of AlH₃ by about 8.94 %. The laser ignition energy of AlH₃/NGO is much lower than that of AlH₃, and the ignition energy decreases linearly as NGO is added from 1 % to 10 %. The flame development process supports the good thermal conductivity assistance effect of an appropriate amount of NGO in the combustion process of AlH₃ in air, which is consistent with the result of oxygen bomb test, indicating that the addition of NGO leads to an improvement in the combustion efficiency of AlH₃.This may provide valuable insights for the development of new high-energy solid propellants.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113802"},"PeriodicalIF":5.8,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solid-to-gas phase transition kinetics of diverse potassium occurrence forms during biomass pellet combustion: Time-resolved detection and multi-step modeling","authors":"Sun Cen ,&nbsp;Wei Xiaolin ,&nbsp;Liu Huimin ,&nbsp;Li Sen ,&nbsp;Li Fei ,&nbsp;Li Teng","doi":"10.1016/j.combustflame.2024.113750","DOIUrl":"10.1016/j.combustflame.2024.113750","url":null,"abstract":"<div><div>The solid-to-gas phase transition of potassium during biomass combustion significantly impacts ash-related issues in bioenergy systems, affecting operational efficiency and equipment longevity. However, the specific mechanisms and kinetics of this transition process remain inadequately understood. This work investigates the time-resolved transition of solid-phase potassium to the gas phase during the combustion of rice husk and wheat straw pellets, combining experimental measurements with theoretical modeling. Tunable diode laser absorption spectroscopy (TDLAS) was employed to measure atomic potassium concentrations 15 mm above burning pellets tray, where gas-phase equilibrium is approached. Key combustion characteristics including thermogravimetric profiles, spectral radiation, and temperature were simultaneously monitored. A novel multi-step model was developed to describe the transition of different forms of solid-phase potassium (organic, exchangeable, and inorganic) to the gas phase. This model integrates TDLAS measurements, observed combustion characteristics, and biomass physicochemical properties. Thermodynamic equilibrium calculations were used to estimate the atomic potassium fraction from total gaseous potassium. The results showed that the solid-to-gas phase transition of organic potassium synchronizes with volatiles release. In contrast, the maximum emission rates of inorganic and exchangeable potassium occurred at the onset of char combustion. The developed model agrees well with the online detection experiments and were further validated by offline ICP analysis of residual ash. While not directly simulating gas-solid interface reactions near the particle surface, this work lays groundwork for future multi-scale modeling of particle-laden flows and reactor-scale phenomena in biomass combustion systems.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113750"},"PeriodicalIF":5.8,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An experimental and modeling study of hydrogen/n-decane blends","authors":"Shangkun Zhou ,&nbsp;A. Abd El-Sabor Mohamed ,&nbsp;Shashank S. Nagaraja ,&nbsp;Pengzhi Wang ,&nbsp;Yuki Murakami ,&nbsp;Jiaxin Liu ,&nbsp;Peter K. Senecal ,&nbsp;Henry J. Curran","doi":"10.1016/j.combustflame.2024.113792","DOIUrl":"10.1016/j.combustflame.2024.113792","url":null,"abstract":"<div><div>In this study, a new mechanism is developed to simulate hydrogen/<em>n</em>-decane blends. It is validated in the temperature range 650–1500 K, at <em>p</em> = 30 bar, for equivalence ratios of 0.5, 1.0, and 2.0 in ‘air’ for 99/1, 95/5 and 80/20 (mol%) blends of hydrogen/<em>n</em>-decane using ignition delay time (IDT) data recorded in both an RCM and in a shock tube. Additionally, the mechanism's performance is assessed against existing literature data for both pure hydrogen and pure <em>n</em>-decane, demonstrating overall satisfactory agreement compared to the experimental measurements.</div><div>This study also explores the effects of <em>n</em>-decane addition to hydrogen at different temperatures (600 K, 900 K, and 1500 K) at <em>p</em> = 30 bar pressure for a stoichiometric mixture (<em>φ</em> = 1.0). At 600 K, where pure hydrogen fails to ignite, the introduction of 1% <em>n</em>-decane initiates ignition, albeit with considerably extended IDTs. At 900 K, the addition of 1% <em>n</em>-decane enhances reactivity, while at 1500 K, it diminishes reactivity and extends the IDT. The underlying reasons for these observed effects are reported.</div><div>We provide valuable insights into the reactivity of dual fuel mixtures of hydrogen and <em>n</em>-decane encompassing low (600–800 K), intermediate (800–1200 K), and high (&gt; 1200 K) temperature ranges. At low and intermediate temperatures, the inclusion of <em>n</em>-decane enhances reactivity. Consequently, for application in practical road transport combustion systems, the use of <em>n</em>-decane or extended-chain <em>n</em>-alkanes is recommended as suitable pilot fuels. Conversely, at high-temperature combustion conditions, the utilization of pilot fuels composed of linear alkanes is observed to impede reactivity.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113792"},"PeriodicalIF":5.8,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental characterization and 3D simulations of turbulent flames assisted by nanosecond plasma discharges","authors":"Victorien P. Blanchard,&nbsp;Yacine Bechane,&nbsp;Nicolas Q. Minesi,&nbsp;Stéphane Q.E. Wang,&nbsp;Benoît Fiorina,&nbsp;Christophe O. Laux","doi":"10.1016/j.combustflame.2024.113709","DOIUrl":"10.1016/j.combustflame.2024.113709","url":null,"abstract":"<div><div>This paper presents quantitative experimental data generated for the validation of plasma-assisted combustion (PAC) simulations. These data are then used to validate the phenomenological model of Castela et al. They are also useful to test other PAC models. In the experiment presented here, Nanosecond Repetitively Pulsed (NRP) discharges are applied to a lean-premixed turbulent methane-air flame initially near the lean blow-off limit. The discharges significantly enhance the combustion and stabilize the flame after a few pulses. Electrical and optical diagnostics are employed to extensively quantify the transient and steady state of the plasma-stabilization process. The flame shape is characterized by OH* chemiluminescence imaging. In the discharge region, OH density profiles are obtained by 1D laser-induced fluorescence, and the gas temperature is measured by optical emission spectroscopy measurements. The local gas temperature increases by 1250 K, and the OH number density rises sevenfold when NRP discharges are applied. These results evidence the cumulative thermal and chemical effects of NRP discharges, which are especially challenging to replicate numerically. A Large Eddy Simulation (LES) of the experiment is performed. Combustion chemistry is modeled by an analytically reduced mechanism, while the plasma discharge is described by the low-CPU cost phenomenological model of Castela et al., which aims to capture the main thermal and chemical effects induced by the discharges. The model of Castela et al. is validated in the burnt gases by the remarkable agreement between the simulations and the experiments regarding the flame shape, the local gas temperature, and the OH number density. More generally, this work demonstrates the relevance of simplified plasma models in LES solvers to simulate complex plasma-assisted burners.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113709"},"PeriodicalIF":5.8,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}