Combustion and Flame最新文献

{"title":"Terpene speciation: Analytical insights into the oxidation and pyrolysis of limonene and 1,8-cineole via molecular-beam mass spectrometry","authors":"Thomas Bierkandt,&nbsp;Nina Gaiser,&nbsp;Jasmin Bachmann,&nbsp;Patrick Oßwald,&nbsp;Markus Köhler","doi":"10.1016/j.combustflame.2024.113854","DOIUrl":"10.1016/j.combustflame.2024.113854","url":null,"abstract":"<div><div>Comprehensive speciation datasets for the stoichiometric oxidation and pyrolysis of the two monoterpenes limonene (C₁₀H₁₆) and 1,8-cineole (C₁₀H₁₈O) are measured in an atmospheric laminar flow reactor using electron-ionization molecular-beam mass spectrometry. This setup allows direct sampling from the reactive flow and preserves the actual gas composition. Furthermore, clear determination of the exact elemental composition of the formed species is possible with the used time-of-flight mass spectrometer. Limonene is a monocyclic terpene and 1,8-cineole is a saturated bicyclic terpene ether and both terpenes might be potential biofuel candidates. Focus in this study is the intermediate temperature region between 673 and 1173 K to obtain insights into the first fuel decomposition steps and the formation of typical soot precursors. The obtained mole fraction profiles for over 40 species in each of the investigated terpenes are a first step for future development and validation of chemical kinetic combustion mechanisms. While the overall species pool is similar, significant concentration differences can be observed for certain combustion intermediates. For limonene, larger quantities of C₈–C₁₀ hydrocarbons are detected and most of them are probably substituted benzenes or cyclohexadienes formed from hydrogen abstraction. Some reaction steps in the decomposition of limonene may also involve initial isomerization of the fuel molecule. In contrast, direct formation of C₇H₁₁ radicals and acetone (C₃H₆O) is identified as an important decomposition step of 1,8-cineole. C₇H₁₁ is then a source of toluene (C₇H₈) and cyclohexadienes (C₆H₈). Generally, a higher sooting propensity of limonene compared to 1,8-cineole can be expected due to the higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in the investigated temperature range. During limonene oxidation, formation of oxygenated species larger than the fuel molecule are observed and might represent carbonyls or cyclic ethers from the first oxygen addition due to low-temperature chemistry.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113854"},"PeriodicalIF":5.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704918","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":"Publication / Copyright Information","authors":"","doi":"10.1016/S0010-2180(24)00527-3","DOIUrl":"10.1016/S0010-2180(24)00527-3","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113818"},"PeriodicalIF":5.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704515","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":"Extended Fourier Neural Operators to learn stiff chemical kinetics under unseen conditions","authors":"Yuting Weng ,&nbsp;Han Li ,&nbsp;Hao Zhang ,&nbsp;Zhi X. Chen ,&nbsp;Dezhi Zhou","doi":"10.1016/j.combustflame.2024.113847","DOIUrl":"10.1016/j.combustflame.2024.113847","url":null,"abstract":"<div><div>The solution of stiff chemical kinetics is recognized as the computational bottleneck for direct simulations of reacting flows. In this study, we extend the concept of Fourier Neural Operator (FNO) to learn stiff chemical kinetics. Specifically, element and mass conservation are introduced as the physical constraints in the extended FNO (EFNO). In addition, the training data are transformed by a Box–Cox strategy to rectify the skewed distribution of the species in the stiff problems. Finally, balanced loss functions are formulated to address the unbalanced sampling data points in complex reacting flow problems. The EFNO model is leveraged to forecast the temporal evolution of chemical species, utilizing an iterative approach wherein the prediction outcome from the previous time step is employed as a new input for subsequent time step prediction. The results in this work demonstrate the significant use of an EFNO approach to solving stiff chemical dynamics in reacting flow simulations, with a time step size comparable to the typical flow time step size. Its prediction accuracy and generalization ability are evaluated by comparing with the original FNO, Deep Nueral Network (DNN) and DeepONet models, in solving toy problems, zero-dimensional hydrogen autoignition, and a three-dimensional hydrogen/ammonia turbulent jet flame. The EFNO is shown to be highly accurate. More importantly, compared with other deep learning models, it can be generalized to stiff chemical kinetic states under unseen conditions, which the model has never trained for. The great performance of EFNO in terms of accuracy and generalization ability suggests that EFNO is a promising solution algorithm for stiff chemical kinetics problems in reacting flows.</div><div><strong>Novelty and Significance Statement:</strong> The novelty of this work lies in the newly developed extended Fourier neural operators (EFNO) to learn stiff chemical kinetics. Specifically, we for the first time evaluated and tested the performance of Fourier neural operators in solving stiff chemical kinetics. More importantly, we extended the original Fourier neural operators to accurately solve for stiff chemical kinetics problems under unseen conditions, which was a very challenging problem for deep learning methods in the literature. Our results demonstrated that the EFNO model solves chemical kinetics in both simple 0D autoignition and complex 3D turbulent jet flames with great accuracy and generalization ability, even for conditions which the training dataset has never encompassed. This work is significant because it developed a neural operator-based algorithm that can significantly accelerate the stiff chemical kinetic solution process in reacting flow simulations with great accuracy even for unseen initial conditions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113847"},"PeriodicalIF":5.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704178","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":"Empirical rate rules for hydroxyl radical reactions with alkenes","authors":"Dapeng Liu,&nbsp;Aamir Farooq","doi":"10.1016/j.combustflame.2024.113849","DOIUrl":"10.1016/j.combustflame.2024.113849","url":null,"abstract":"<div><div>Alkenes are not only constituents of practical fuels but are also key intermediates of the oxidation and pyrolysis of larger hydrocarbons. The interactions between alkenes and hydroxyl (OH) radicals play a pivotal role in the depletion of alkenes. Literature measurements of OH + alkene reactions have been limited to small molecules containing fewer than seven carbon atoms. Moreover, the competition between various channels in these reactions remains poorly understood. Here, we studied channel-specific rate coefficients of propene + OH and combined it with literature measurements to derive rate rules for alkene + OH reactions. This work presents the first direct measurement of the channel-specific rate coefficients (<em>k</em>_1a) for the reaction of OH + propene → allyl radical + H₂O. Using a sensitive UV absorption diagnostic scheme at 220 nm, we tracked the time-resolved formation of the product allyl radical. Our determined rate coefficients are described by the following Arrhenius expression (unit: cm³molecule^-1s^-1):<span><math><mrow><msub><mi>k</mi><mrow><mn>1</mn><mi>a</mi></mrow></msub><mo>=</mo><mn>1.38</mn><mspace></mspace><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>10</mn></mrow></msup><msup><mi>e</mi><mrow><mo>(</mo><mfrac><mrow><mo>−</mo><mn>3128</mn></mrow><mi>T</mi></mfrac><mo>)</mo></mrow></msup></mrow></math></span> (900–1200 K)</div><div>Between 900 and 1200 K, the H abstraction from allylic C<img>H bonds of propene accounted for 55 - 65 % of the overall reactivity and exhibited a gentle positive temperature dependence.</div><div>Our investigation of hydroxyl reaction with propene serves as a prototype reaction of a molecule containing allylic C<img>H bonds. In conjunction with literature-reported rate coefficients of OH + C₄ – C₆ alkenes, we propose a set of rate rules encompassing vinylic, alkylic, and allylic C<img>H bonds. These rate rules could be used to predict the behavior of large alkene reactions with OH when direct measurements and calculations are not available. Notably, our rate rules revealed that the primary allylic C<img>H bonds in propene and iso-butene react with about a 40 % slower rate with OH than the primary allylic C<img>H bonds in 2-alkenes, cautioning against direct analogy between the rate coefficients of these C<img>H bonds. Additionally, the secondary allylic C<img>H bonds in a <em>trans</em>-2-alkene molecules are 33 % more efficient in consuming OH radicals than those in the cis-2-alkenes.</div><div>These rate rules are incorporated in literature models of alkenes and biofuels containing similar C<img>H bonds, thus enabling improved accuracy of model predictions. Our work provides new insights into the channel-specific competition of OH + alkene reactions, and benefits automated modeling of alkene molecules and double-bond containing biofuels.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113849"},"PeriodicalIF":5.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704915","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":"Theoretical study on the combustion kinetics of trimethylamine and the key intermediate N-methylmethanimine","authors":"Sihao Wang ,&nbsp;Yiran Zhang ,&nbsp;Li Fu ,&nbsp;Hongbo Ning","doi":"10.1016/j.combustflame.2024.113860","DOIUrl":"10.1016/j.combustflame.2024.113860","url":null,"abstract":"<div><div>The combustion kinetics of trimethylamine (TMA) are systematically studied based on the high-level <em>ab initio</em> calculations. Reaction pathways include the direct C–N and C–H bond fissions, intramolecular H-shift, and H-abstraction by five small radicals (H/CH₃/OH/NH₂/HO₂) for TMA, as well as subsequent TMA radical isomerization and decomposition. The potential energy profiles are explored at the CCSD(T)/cc-pV<em>x</em>Z(<em>x</em> = T, Q) level and the results reveal that <em>N</em>-methylmethanimine (MMI) is the key intermediate for TMA decomposition. Therefore, the H-abstraction reaction kinetics of MMI with H/CH₃/OH/NH₂/HO₂ radicals are also investigated. The atomization method is further adopted to determine the standard enthalpy of formation of each species, showing good agreement with the available literature results. For the H-abstraction reactions of TMA/MMI + H/CH₃/OH/NH₂/HO₂, multi-structural variational transition state theory combined with small-curvature tunneling approximation (MS-CVT/SCT) is employed to obtain the high-pressure limit (HPL) rate constants and the conventional transition state theory (TST) rate constants in MS-CVT/SCT method are obtained by CCSD(T)/cc-pVxZ(x = T, Q) energies. For the unimolecular reactions of TMA decomposition, Rice-Ramsberger-Kassel-Marcus/Master-Equation (RRKM/ME) theory is used to obtain the pressure-dependent rate constants. The calculated rate constants are also in good agreement with the available experimental results and the comparison of rate constants for four MMI formation channels shows that the <em>β</em>-scissions of (CH₃)₂NCH₂ to form MMI + CH₃ and CH₃NCH₃ to form MMI + H are dominant. Due to the lack of experimental data for TMA under combustion, the performance of H-abstraction reactions of MMI + H/CH₃/OH/NH₂/HO₂ is evaluated by updating a dimethylamine kinetic model and then assessed against the measured ignition delay time. It shows that the updated kinetic model can better reproduce the experimental measurements. The comprehensive kinetic details presented are invaluable for the development of kinetic model for TMA and the refinement of kinetic models for other secondary and tertiary amines.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113860"},"PeriodicalIF":5.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704916","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":"Investigation of the criteria for construction of reliable surrogate fuels: A case study of Jet-A aviation kerosene","authors":"Yachao Chang,&nbsp;Shuai Huang,&nbsp;Hongda Li,&nbsp;Ming Jia","doi":"10.1016/j.combustflame.2024.113866","DOIUrl":"10.1016/j.combustflame.2024.113866","url":null,"abstract":"<div><div>Surrogate fuels are usually constructed by optimizing component selection and component proportions to match the physicochemical indexes of practical fuels. The interaction among the selected components and the influence of the weight factors of the physicochemical indexes on the combustion characteristics of the surrogate fuel have not been well investigated in previous research. In this paper, a systematical method is proposed to construct the Jet-A aviation kerosene surrogate fuel by combining the principle of the selection of the surrogate components and the genetic algorithm, in which the weight factors of the physicochemical indexes are introduced. First, 900 cases including nine groups of surrogate component schemes and 100 groups of weight factor schemes are generated using the Sobol function. Then, optimization is carried out using the genetic algorithm for the 900 surrogate fuels with the candidate component proportions as the input variables and the selected physicochemical properties as the optimization targets. Subsequently, the results of all the surrogate fuels concerning component proportions, physicochemical properties, and combustion characteristics are further analyzed, especially for the prediction performance of the surrogate fuels under different schemes on the combustion characteristics of ignition delay times, laminar flame speeds, and O₂/CO/CO₂ concentrations. It is found that proper weight factors can enhance the prediction performance of the surrogate fuels, especially for the surrogate fuels with fewer surrogate components. However, the optimal limit of the surrogate fuel performance is determined once the surrogate components are confirmed. Through the comprehensive orthogonal analysis and sensitivity analysis on the results of the surrogate fuels, the criteria of surrogate fuel construction for Jet-A are further present: the surrogate fuels do not need to keep the same component proportions as that in the practical fuel. To ensure the reliability of the surrogate fuels, the relative weight factor of the derived cetane number should be enhanced by at least 15 %, while that of the aromatics fraction should be larger than 10 %.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113866"},"PeriodicalIF":5.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704917","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":"Oxidation of magnesium particles in a fluidized bed reactor","authors":"Alice Wittmann ,&nbsp;Tomasz Wronski ,&nbsp;Evgeny Shafirovich ,&nbsp;Cornelius Schönnenbeck ,&nbsp;Alain Brillard ,&nbsp;Jean-François Brilhac ,&nbsp;Valérie Tschamber","doi":"10.1016/j.combustflame.2024.113853","DOIUrl":"10.1016/j.combustflame.2024.113853","url":null,"abstract":"<div><div>Magnesium is a promising fuel for the metal-enabled cycle of renewable energy and for space power systems. However, the existing methods for combustion of magnesium powders have difficulties with maintaining flame stability. Further, the kinetics and mechanisms of high-temperature oxidation of magnesium powders, needed for combustion modeling, are still not well understood. In the present work, a fluidized bed reactor was used to study the oxidation of spherical magnesium particles in an oxygen/helium environment at temperatures of 530, 550, and 570 °C. The extent of conversion was determined based on the measured oxygen concentration in the exhaust gas. The obtained curves of the extent of conversion and of the conversion rate were analyzed using the Avrami-Erofeev equation and the Mampel-Delmon model. The activation energy obtained with the Avrami-Erofeev equation was 191 or 198 kJ∙mol⁻¹, depending on the dimension (3 or 2, respectively). The Mampel-Delmon approach has shown that the activation energies of nucleation and growth are equal to 189 and 120 kJ∙mol⁻¹, respectively, i.e., the former is virtually the same as the apparent activation energy obtained with the Avrami-Erofeev model at a dimension of 3. With increasing temperature, the rate of nucleation rises faster than the rate of growth. The results obtained with the Mampel-Delmon approach help understand the oxidation mechanism, while the Avrami-Erofeev equation and the obtained apparent activation energy can be used in combustion modeling for simplicity.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113853"},"PeriodicalIF":5.8,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704913","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":"Advancing the C4 low-temperature oxidation chemistry through species measurements in a rapid compression machine, Part A: 1-Butene","authors":"Jesus Caravaca-Vilchez ,&nbsp;Jiaxin Liu ,&nbsp;Pengzhi Wang ,&nbsp;Yuki Murakami ,&nbsp;Henry J. Curran ,&nbsp;Karl Alexander Heufer","doi":"10.1016/j.combustflame.2024.113833","DOIUrl":"10.1016/j.combustflame.2024.113833","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Alkene chemistry plays a crucial role in the autoignition and oxidation of larger hydrocarbons. Unlike its other isomers, 1-butene is characterized by a two-stage ignition process. Various previous studies of 1-butene oxidation have used experimental techniques, including the measurement of ignition delay times in rapid compression machines (RCM) and in shock tubes, the determination of flame velocities, and the measurement of species concentrations in flames and in jet-stirred reactors (JSR). JSR studies provide an important insight into intermediate species formation at low temperatures but are constrained to low pressures and/or highly diluted conditions. To bridge the gap between JSR and engine-relevant conditions, this study presents species concentration measurements during the oxidation of 1-butene at 733 K and 30 bar under stoichiometric ’air-like’ conditions in an RCM, complemented by IDT measurements in the temperature range of 680–910 K. We designed an innovative 2-valve sampling setup to reduce quantitative uncertainties and the time required for species measurements. Our results indicate that existing 1-butene models fail to accurately predict the IDTs and the formation of the key oxidation intermediates. In response, potential optimizations for an improved kinetic model based on NUIGMech1.3 are discussed. Rate parameters for predominantly fuel consumption pathways, along with other reactions and thermochemical properties in the Waddington mechanism, have been altered within expected uncertainty limits to reflect the experimentally observed IDTs and species concentrations of this study and other validation data from the literature. However, the refined model does not predict the formation of 2-ethenyloxirane and ethene, indicating a gap in our understanding of the chemistry of these components. Overall, this study demonstrates the importance of measuring intermediates under the same conditions as IDTs to accurately address deficiencies in current kinetic mechanisms, and represents the first phase of a comprehensive investigation advancing the understanding of C&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; oxidation chemistry.&lt;/div&gt;&lt;div&gt;&lt;strong&gt;Novelty and significance statement&lt;/strong&gt;&lt;/div&gt;&lt;div&gt;The novelty of this research lies in the design of an innovative sampling system for RCM species measurements, lowering the time for experimental execution and the uncertainties of the measurements. This enabled first-time species measurements during the oxidation of butene isomers in an RCM at high pressure and low level of dilution, contributing to the refinement of the 1-butene sub-mechanism within the NUIGMech1.3 framework. This research contributes to the understanding of the oxidation of alkenes, an important class of intermediates in gasoline and biofuel combustion. It emphasizes the need to measure intermediate species at the same conditions as ignition delay times, which are essential for unde","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113833"},"PeriodicalIF":5.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704914","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":"Numerical study on the combustion characteristics of n-dodecane/PODE3 blend spray from the perspective of the second law of thermodynamics","authors":"Haoran Li ,&nbsp;Yachao Chang ,&nbsp;Rui Ding ,&nbsp;Tiemin Xuan ,&nbsp;Yizhuo Feng ,&nbsp;Ming Jia","doi":"10.1016/j.combustflame.2024.113850","DOIUrl":"10.1016/j.combustflame.2024.113850","url":null,"abstract":"<div><div>Polyoxymethylene dimethyl ethers (PODE), as a potential e-fuel, can realize the carbon neutrality for internal combustion engines. Existing studies on PODE are primarily engine-based, leading to contradictory conclusions about fuel consumption and pollutant emissions due to the different engine specifications and operating conditions. This work applies the second law of thermodynamics under constant-volume conditions to analyze fuel economy and emissions characteristics without the influence of particular test conditions or engine types. The fundamental fuel economic and emission-related behaviors of pure <em>n</em>-dodecane and PODE₃/<em>n</em>-dodecane blended fuels were numerically studied. For the spray and combustion processes, compared with <em>n</em>-dodecane, the blended fuel exhibits the low-temperature heat release (LTHR) in the region with leaner fuel/air mixture and higher temperature. However, the high-temperature heat release (HTHR) of the blended fuel is closer to the stoichiometric combustion but with lower temperatures. Blending PODE₃ into <em>n</em>-dodecane increases the exergy destruction induced by chemical reactions but decreases the exergy destruction related to heat conduction and mass transfer, resulting in a basically unchanged overall potential maximum fuel economy. Heightened sensitivity of the exergy destruction from chemical reactions to temperature and equivalence ratio is found under low-temperature and high-equivalence ratio conditions. This sensitivity trend is nearly consistent for different PODE₃/<em>n</em>-dodecane blends. The exergy destruction arising from chemical reactions for the LTHR of PODE₃ is higher than that of <em>n</em>-dodecane. Less exergy destruction induced from chemical reactions can be achieved by controlling the combustion temperature higher than 1760 K and 1900 K respectively for <em>n</em>-dodecane and the blended fuel. Moreover, both nitrogen oxide (NO_x) and soot are reduced for the blended fuel compared with <em>n</em>-dodecane. Notably, the trade-off relationships of NO_x-chemical exergy destruction as well as NO_x-soot, can be improved by blending PODE₃ into <em>n</em>-dodecane.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113850"},"PeriodicalIF":5.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704181","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":"Advanced simulation of combustion characteristics for hazardous nitrogenous compounds using multi-component gaseous fuels","authors":"Huiming Sun,&nbsp;Song Guo,&nbsp;Shuyi Shen,&nbsp;Renming Pan,&nbsp;Yitao Liu,&nbsp;Le Wang","doi":"10.1016/j.combustflame.2024.113856","DOIUrl":"10.1016/j.combustflame.2024.113856","url":null,"abstract":"<div><div>Nitrogen-containing compounds are widely used as raw materials or intermediates in industries such as pharmaceuticals, dyes, explosives, and plastics. However, there is a lack of reliable and effective research methods for accurately predicting the consequences of accidents involving hazardous nitrogenous chemicals. This paper presents a novel method for simulating the combustion characteristics of nitrogen-containing hazardous chemicals, such as Hexogen (RDX) and Octogen (HMX), using multi-component gaseous small molecule fuels. The method relies on a theoretical modeling approach and numerical simulation to predict the behavior of intermediate combustion products. Key advancements include establishing a standard modeling method identifying 11 different small molecule components, and creating predictive model libraries through combinatorial methods. This approach moves away from traditional target matching by calculating proportion coefficients for each component based on their contribution to ignition characteristics. The feasibility and accuracy of this method were validated through experiments using a microscale calorimeter (MCC), demonstrating a high correlation (0.9981) between experimental results and model predictions. This method was found particularly effective for real-time prediction of thermal hazards in high-rise building scenarios, exemplified by 2-Ethylhexyl nitrate (EHN). The paper concludes with the identification of optimal multi-component models for RDX and HMX, highlighting the significant role of hydrogen cyanide (HCN) and unsaturated hydrocarbons in these models.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113856"},"PeriodicalIF":5.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703827","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}