Pub Date : 2026-01-10DOI: 10.1016/j.combustflame.2026.114780
Jingruo Chen , Kun Li , Fan Peng , Daoguan Ning , Xiaocheng Mi , Yutao Zheng , Shijie Xu , Dongping Chen , Xin Wen , Yingzheng Liu , Weiwei Cai
Iron powder is regarded as a highly promising zero-carbon energy carrier, with combustion as its primary mode of energy release. However, iron dust flames exhibit poor stability, prompting the common practice of co-firing with hydrocarbon fuels to ensure stable combustion. This approach still yields carbon emissions. In pursuit of a fully zero-carbon iron-fuel cycle, the present work firstly investigates the combustion characteristics of single iron particles under ammonia co-firing conditions. Two distinct combustion behaviors, including micro-explosion and fragment release, are observed. The fragments are inferred to be the nanoparticle cloud based on 30k fps high-speed shadowgraphy. Under ammonia as the carrier gas, the micro-explosion probability of iron particles exceeds that observed with methane or nitrogen, significantly at oxygen mole fractions of 10.9%–20.4%. This phenomenon likely arises from iron nitride decomposition at the liquid iron (L1)–liquid iron oxide (L2) interface. Furthermore, the micro-explosion probability in ammonia/iron combustion decreases with increasing oxygen concentration. The micro-explosion delay time (MDT) is defined to quantify the effect of particle size on liquid-phase combustion under ammonia co-firing conditions. Further experimental results show that at higher oxygen concentrations, MDT is nearly proportional to the inverse of oxygen mass fraction, suggesting that particle oxidation is limited by external oxygen diffusion. However, at Y 12.5%, MDT deviates from the linear correlation. In the low oxygen concentration cases, iron nitride may react with absorbed oxygen and impede the internal transport of oxygen, thereby constraining the oxidation rate of iron and delaying the formation of a complete core–shell structure. Overall, ammonia/iron co-firing technology shows great promise for regulating micro-explosions and represents a crucial step toward realizing a genuinely zero-carbon iron-fuel cycle. Novelty and Significance Statement The fundamental combustion characteristics of iron particles under ammonia co-firing conditions were first investigated in this work. The micro-explosion probability of iron particles in a hot ammonia environment is significantly high and decreases with increasing oxygen concentration in the bulk gas. The effects of particle size and ambient oxygen concentration on the iron particles combustion time under ammonia co-firing conditions were quantitatively analyzed. The potential mechanisms underlying the influence of ammonia on the micro-explosion of iron particles were discussed. The ammonia/iron co-firing technology offers a novel approach for achieving a truly zero-carbon iron-fuel cycle.
{"title":"Combustion characteristics of single iron particles under ammonia co-firing conditions","authors":"Jingruo Chen , Kun Li , Fan Peng , Daoguan Ning , Xiaocheng Mi , Yutao Zheng , Shijie Xu , Dongping Chen , Xin Wen , Yingzheng Liu , Weiwei Cai","doi":"10.1016/j.combustflame.2026.114780","DOIUrl":"10.1016/j.combustflame.2026.114780","url":null,"abstract":"<div><div>Iron powder is regarded as a highly promising zero-carbon energy carrier, with combustion as its primary mode of energy release. However, iron dust flames exhibit poor stability, prompting the common practice of co-firing with hydrocarbon fuels to ensure stable combustion. This approach still yields carbon emissions. In pursuit of a fully zero-carbon iron-fuel cycle, the present work firstly investigates the combustion characteristics of single iron particles under ammonia co-firing conditions. Two distinct combustion behaviors, including micro-explosion and fragment release, are observed. The fragments are inferred to be the nanoparticle cloud based on 30k fps high-speed shadowgraphy. Under ammonia as the carrier gas, the micro-explosion probability of iron particles exceeds that observed with methane or nitrogen, significantly at oxygen mole fractions of 10.9%–20.4%. This phenomenon likely arises from iron nitride decomposition at the liquid iron (L1)–liquid iron oxide (L2) interface. Furthermore, the micro-explosion probability in ammonia/iron combustion decreases with increasing oxygen concentration. The micro-explosion delay time (MDT) is defined to quantify the effect of particle size on liquid-phase combustion under ammonia co-firing conditions. Further experimental results show that at higher oxygen concentrations, MDT is nearly proportional to the inverse of oxygen mass fraction, suggesting that particle oxidation is limited by external oxygen diffusion. However, at Y<span><math><msub><mrow></mrow><mrow><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></msub></math></span> <span><math><mo>=</mo></math></span> 12.5%, MDT deviates from the linear correlation. In the low oxygen concentration cases, iron nitride may react with absorbed oxygen and impede the internal transport of oxygen, thereby constraining the oxidation rate of iron and delaying the formation of a complete core–shell structure. Overall, ammonia/iron co-firing technology shows great promise for regulating micro-explosions and represents a crucial step toward realizing a genuinely zero-carbon iron-fuel cycle. <strong>Novelty and Significance Statement</strong> The fundamental combustion characteristics of iron particles under ammonia co-firing conditions were first investigated in this work. The micro-explosion probability of iron particles in a hot ammonia environment is significantly high and decreases with increasing oxygen concentration in the bulk gas. The effects of particle size and ambient oxygen concentration on the iron particles combustion time under ammonia co-firing conditions were quantitatively analyzed. The potential mechanisms underlying the influence of ammonia on the micro-explosion of iron particles were discussed. The ammonia/iron co-firing technology offers a novel approach for achieving a truly zero-carbon iron-fuel cycle.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114780"},"PeriodicalIF":6.2,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922306","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}
Pub Date : 2026-01-10DOI: 10.1016/j.combustflame.2026.114777
Zeyu Yan, Xiangyu Nie, Qizhe Wen, Shuoxun Zhang, Shengkai Wang
This study presents a systematic characterization of burner-stabilized lean hydrogen flames across a wide range of equivalence ratios, dilution factors, and flow rates. Spatially resolved measurements of three-dimensional temperature and OH distributions were achieved. A comprehensive dataset of over 200 flame cases was obtained, enabling accurate determination of regime diagrams for different flame modes. Linear stability analyses using simplified models and direct numerical simulations (DNS) were performed and compared with the experimental results. The most unstable wavenumbers predicted by DNS analysis of the linearized dispersion relation using detailed chemistry and realistic thermal boundary conditions were very close to the observed dominant wavenumbers of cellular flames at steady states. The cellular structures were found to be critically important in stabilizing the flame, especially at nominal equivalence ratios near the lean flammability limit. The combined effect of curvature-induced flame acceleration, local flow expansion/compression near the burner surface, and stratification of equivalence ratio caused by Soret diffusion created regions of reduced flow speed and enriched hydrogen concentration that helped anchor flames at nominal conditions where they would have blown off without the flame cells. The results of the present study should prove useful to the fundamental understanding of lean hydrogen flame dynamics and to the design improvement of practical hydrogen combustors.
Novelty and significance statement
This work, to the authors’ knowledge, presents the first spatially resolved measurements of three-dimensional temperature and OH concentration fields in cellular flames of lean hydrogen mixtures. These measurements have quantified the ultimate statistics of burner-stabilized cellular flame morphology at steady state, which are further compared with the results of linear stability analysis. The cellular structures were found to be critically important in stabilizing the flames, especially at nominal equivalence ratios near the lean flammability limit, where they would have blown off without the flame cells. Complementary numerical simulations have revealed the key mechanism of cellular flame stabilization. A systematic characterization of cellular flame instabilities across a wide range of equivalence ratios, dilution factors, and flow rates was also conducted, yielding a comprehensive dataset of flame modes, regime diagrams, and three-dimensional scalar distributions. The new findings and data obtained in the present study promise to advance both fundamental research on flame dynamics and practical applications of hydrogen combustion.
{"title":"Quantitative 3D measurements of temperature and OH in cellular H2/O2/N2 flames on a porous-plug burner","authors":"Zeyu Yan, Xiangyu Nie, Qizhe Wen, Shuoxun Zhang, Shengkai Wang","doi":"10.1016/j.combustflame.2026.114777","DOIUrl":"10.1016/j.combustflame.2026.114777","url":null,"abstract":"<div><div>This study presents a systematic characterization of burner-stabilized lean hydrogen flames across a wide range of equivalence ratios, dilution factors, and flow rates. Spatially resolved measurements of three-dimensional temperature and OH distributions were achieved. A comprehensive dataset of over 200 flame cases was obtained, enabling accurate determination of regime diagrams for different flame modes. Linear stability analyses using simplified models and direct numerical simulations (DNS) were performed and compared with the experimental results. The most unstable wavenumbers predicted by DNS analysis of the linearized dispersion relation using detailed chemistry and realistic thermal boundary conditions were very close to the observed dominant wavenumbers of cellular flames at steady states. The cellular structures were found to be critically important in stabilizing the flame, especially at nominal equivalence ratios near the lean flammability limit. The combined effect of curvature-induced flame acceleration, local flow expansion/compression near the burner surface, and stratification of equivalence ratio caused by Soret diffusion created regions of reduced flow speed and enriched hydrogen concentration that helped anchor flames at nominal conditions where they would have blown off without the flame cells. The results of the present study should prove useful to the fundamental understanding of lean hydrogen flame dynamics and to the design improvement of practical hydrogen combustors.</div><div><strong>Novelty and significance statement</strong></div><div>This work, to the authors’ knowledge, presents the first spatially resolved measurements of three-dimensional temperature and OH concentration fields in cellular flames of lean hydrogen mixtures. These measurements have quantified the ultimate statistics of burner-stabilized cellular flame morphology at steady state, which are further compared with the results of linear stability analysis. The cellular structures were found to be critically important in stabilizing the flames, especially at nominal equivalence ratios near the lean flammability limit, where they would have blown off without the flame cells. Complementary numerical simulations have revealed the key mechanism of cellular flame stabilization. A systematic characterization of cellular flame instabilities across a wide range of equivalence ratios, dilution factors, and flow rates was also conducted, yielding a comprehensive dataset of flame modes, regime diagrams, and three-dimensional scalar distributions. The new findings and data obtained in the present study promise to advance both fundamental research on flame dynamics and practical applications of hydrogen combustion.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114777"},"PeriodicalIF":6.2,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922308","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}
Pub Date : 2026-01-09DOI: 10.1016/j.combustflame.2026.114765
Jumeng Fan, Huahua Xiao
Numerical simulations were performed to study the choked flame and its transition to detonation in a stoichiometric hydrogen-oxygen mixture in a channel equipped with continuous triangular obstacles. A fifth-order numerical method was used to solve the unsteady, fully-compressible Navier-Stokes equations coupled to a chemical-diffusive model on a dynamically adapting mesh. The simulations qualitatively and quantitatively agree with experiments. The effects of initial pressure and blockage ratio (br) were examined. The results show that reaching the Chapman-Jouguet deflagration speed (SCJ) is a necessary condition for the detonation transition. When the initial pressure increases or br decreases, the combustion wave after accelerating to SCJ exhibits three distinct propagation regimes in the following sequence: (1) the perpetual choked flame regime where the flame speed never exceeds the sound speed of combustion products; (2) the regime of choked flame to detonation transition characterized by DDT following sustained choked flame propagation; (3) the direct detonation transition regime featuring no obvious choking stage prior to detonation transition. A closer analysis reveals that br has competing effects on detonation transition: Higher br enhances local detonation initiation through increased strength and cycles of shock reflection in obstacle gaps despite faster shock attenuation, while simultaneously supresses local detonation survival by reducing the critical minimum shock-reaction front distance prior to DDT (). A criterion for detonation survival is established as >0.9, where λ denotes the detonation cell size.
{"title":"Choked flame and its transition to detonation in an obstructed channel","authors":"Jumeng Fan, Huahua Xiao","doi":"10.1016/j.combustflame.2026.114765","DOIUrl":"10.1016/j.combustflame.2026.114765","url":null,"abstract":"<div><div>Numerical simulations were performed to study the choked flame and its transition to detonation in a stoichiometric hydrogen-oxygen mixture in a channel equipped with continuous triangular obstacles. A fifth-order numerical method was used to solve the unsteady, fully-compressible Navier-Stokes equations coupled to a chemical-diffusive model on a dynamically adapting mesh. The simulations qualitatively and quantitatively agree with experiments. The effects of initial pressure and blockage ratio (br) were examined. The results show that reaching the Chapman-Jouguet deflagration speed (S<sub>CJ</sub>) is a necessary condition for the detonation transition. When the initial pressure increases or br decreases, the combustion wave after accelerating to S<sub>CJ</sub> exhibits three distinct propagation regimes in the following sequence: (1) the perpetual choked flame regime where the flame speed never exceeds the sound speed of combustion products; (2) the regime of choked flame to detonation transition characterized by DDT following sustained choked flame propagation; (3) the direct detonation transition regime featuring no obvious choking stage prior to detonation transition. A closer analysis reveals that br has competing effects on detonation transition: Higher br enhances local detonation initiation through increased strength and cycles of shock reflection in obstacle gaps despite faster shock attenuation, while simultaneously supresses local detonation survival by reducing the critical minimum shock-reaction front distance prior to DDT (<span><math><msub><mi>d</mi><mrow><mi>s</mi><mo>−</mo><mi>f</mi><mo>,</mo><mrow><mspace></mspace><mtext>min</mtext></mrow></mrow></msub></math></span>). A criterion for detonation survival is established as <span><math><mrow><msub><mi>d</mi><mrow><mi>s</mi><mo>−</mo><mi>f</mi><mo>,</mo><mrow><mspace></mspace><mtext>min</mtext></mrow></mrow></msub><mo>/</mo><mi>λ</mi></mrow></math></span> >0.9, where λ denotes the detonation cell size.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114765"},"PeriodicalIF":6.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922305","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}
Pub Date : 2026-01-09DOI: 10.1016/j.combustflame.2026.114779
Haifeng Wang
<div><div>The mixture fraction has long served as a fundamental scalar in the analysis of non-premixed combustion. Despite its critical role, a comprehensive understanding of its key properties – boundedness, monotonicity, and stoichiometry preservation – remains incomplete, particularly under realistic conditions involving differential molecular diffusion. This study aims to address this gap by systematically examining the properties of element-based mixture fraction definitions, including the widely used Bilger mixture fraction. A total of twenty-nine laminar opposed jet flames were numerically simulated, covering a variety of hydrocarbon fuels and blends, as well as carbon-free fuels such as hydrogen and ammonia. The simulations span a wide range of strain rates, from low stretching to near extinction, providing a broad and detailed dataset for analysis. New diagnostic parameters are introduced to quantify the deviations of different mixture fraction definitions from the desired properties. Among all element-based mixture fraction definitions, the Bilger mixture fraction is the only one that consistently preserves the stoichiometric condition and is proven to be unique among linear formulations. However, no element-based mixture fraction satisfies all desired properties simultaneously. Each definition exhibits distinct characteristics depending on the fuel and flame configuration. The stoichiometry-preserving Bilger mixture fraction shows monotonicity violations generally, occurring only near the fuel or oxidizer boundaries and never around the stoichiometric region. This separation of monotonicity and stoichiometry issues suggests that the Bilger mixture fraction’s monotonicity violations can potentially be corrected without compromising its stoichiometric accuracy. The carbon-based element mixture fraction is either monotonic or has occasional violations near the fuel boundary, while the hydrogen-based definition follows a similar trend with some violations within the domain. No boundedness violation is observed at the oxidizer boundary for either carbon- or hydrogen-based definitions. In contrast, the oxygen-based mixture fraction exhibits more extensive monotonicity violations that can occur at any location depending on the flame. The nitrogen-based definition tends to show the least monotonicity violation in hydrocarbon flames but the most in ammonia flames, with or without hydrogen blending. Correlations among mixture fractions are also observed, e.g., when the Bilger mixture fraction exhibits boundedness violation, the carbon-based definition remains bounded at the same boundary. These findings constitute the first comprehensive quantitative assessment of mixture fraction properties under differential molecular diffusion. Beyond their theoretical value, the results provide practical insights for developing improved mixture fraction formulations. In particular, a hybrid mixture fraction concept is introduced, combining different definiti
{"title":"Studies of boundedness, monotonicity, and stoichiometry preservation of mixture fraction definitions for non-premixed combustion","authors":"Haifeng Wang","doi":"10.1016/j.combustflame.2026.114779","DOIUrl":"10.1016/j.combustflame.2026.114779","url":null,"abstract":"<div><div>The mixture fraction has long served as a fundamental scalar in the analysis of non-premixed combustion. Despite its critical role, a comprehensive understanding of its key properties – boundedness, monotonicity, and stoichiometry preservation – remains incomplete, particularly under realistic conditions involving differential molecular diffusion. This study aims to address this gap by systematically examining the properties of element-based mixture fraction definitions, including the widely used Bilger mixture fraction. A total of twenty-nine laminar opposed jet flames were numerically simulated, covering a variety of hydrocarbon fuels and blends, as well as carbon-free fuels such as hydrogen and ammonia. The simulations span a wide range of strain rates, from low stretching to near extinction, providing a broad and detailed dataset for analysis. New diagnostic parameters are introduced to quantify the deviations of different mixture fraction definitions from the desired properties. Among all element-based mixture fraction definitions, the Bilger mixture fraction is the only one that consistently preserves the stoichiometric condition and is proven to be unique among linear formulations. However, no element-based mixture fraction satisfies all desired properties simultaneously. Each definition exhibits distinct characteristics depending on the fuel and flame configuration. The stoichiometry-preserving Bilger mixture fraction shows monotonicity violations generally, occurring only near the fuel or oxidizer boundaries and never around the stoichiometric region. This separation of monotonicity and stoichiometry issues suggests that the Bilger mixture fraction’s monotonicity violations can potentially be corrected without compromising its stoichiometric accuracy. The carbon-based element mixture fraction is either monotonic or has occasional violations near the fuel boundary, while the hydrogen-based definition follows a similar trend with some violations within the domain. No boundedness violation is observed at the oxidizer boundary for either carbon- or hydrogen-based definitions. In contrast, the oxygen-based mixture fraction exhibits more extensive monotonicity violations that can occur at any location depending on the flame. The nitrogen-based definition tends to show the least monotonicity violation in hydrocarbon flames but the most in ammonia flames, with or without hydrogen blending. Correlations among mixture fractions are also observed, e.g., when the Bilger mixture fraction exhibits boundedness violation, the carbon-based definition remains bounded at the same boundary. These findings constitute the first comprehensive quantitative assessment of mixture fraction properties under differential molecular diffusion. Beyond their theoretical value, the results provide practical insights for developing improved mixture fraction formulations. In particular, a hybrid mixture fraction concept is introduced, combining different definiti","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114779"},"PeriodicalIF":6.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922307","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}
Pub Date : 2026-01-09DOI: 10.1016/j.combustflame.2026.114769
Shixing Wang , Ayman M. Elbaz , Zhihua Wang , William L. Roberts
Ammonia (NH3), recognized as a promising carbon-neutral fuel with high hydrogen content, has the potential to diversify the global energy system. One strategy to improve its combustion characteristics is to blend it with a highly reactive fuel. This study investigates blends of NH₃ and 2-methylfuran (2MF), a biofuel suitable for use as an alternative in engines. Unstretched laminar burning velocity (SL) and Markstein length (Lb) of various 2MF/NH3/air blends were experimentally determined using spherically propagating premixed flames. Measurements of SL were conducted at initial temperatures of 333–373 K, initial pressures of 0.1, 0.3 and 0.5 MPa, equivalence ratios (ϕ) ranging from f 0.8 to 1.4, and ammonia mole fraction (XNH3) from 0 to 0.6. The addition of 2MF was found to substantially enhance the combustion characteristics of ammonia. Increasing the ammonia content up to XNH3=0.6 significantly reduces the SL of 2MF/air flame speed, with a maximum reduction of approximately 20 cm/s observed at ϕ = 1.1. Lb notably decreases with increasing ϕ, while the effect of XNH3 varies with ϕ. A flame instability assessment was performed by determining critical Peclet number and Karlovitz number at the onset of flame instability. The temperature and pressure dependences of SL were obtained experimentally. The normalized flame speed SL/SL0 versus XNH3 follows a consistent trend across different pressures and temperatures. Based on these findings, an empirical correlation was developed to predict SL of 2MF/NH3/air blends under various conditions of P, T, ϕ and XNH3. A composite chemical kinetic model of 2MF/NH3/air reliably predicted SL obtained in this work. Sensitivity and reaction path analyses indicated that SL of 2MF/NH3/air blends is governed by the oxidation of small hydrocarbon and amine molecules, which compete for the same radical pool. Furthermore, when ammonia content is high (XNH3=0.5–1.0), blending ammonia with 2MF provides greater enhancement than blending ammonia with hydrogen or methane.
{"title":"Experimental and kinetic modeling study of laminar burning velocity of 2-methylfuran and ammonia blends at elevated pressures and temperatures","authors":"Shixing Wang , Ayman M. Elbaz , Zhihua Wang , William L. Roberts","doi":"10.1016/j.combustflame.2026.114769","DOIUrl":"10.1016/j.combustflame.2026.114769","url":null,"abstract":"<div><div>Ammonia (NH<sub>3</sub>), recognized as a promising carbon-neutral fuel with high hydrogen content, has the potential to diversify the global energy system. One strategy to improve its combustion characteristics is to blend it with a highly reactive fuel. This study investigates blends of NH₃ and 2-methylfuran (2MF), a biofuel suitable for use as an alternative in engines. Unstretched laminar burning velocity (S<sub>L</sub>) and Markstein length (L<sub>b</sub>) of various 2MF/NH<sub>3</sub>/air blends were experimentally determined using spherically propagating premixed flames. Measurements of S<sub>L</sub> were conducted at initial temperatures of 333–373 K, initial pressures of 0.1, 0.3 and 0.5 MPa, equivalence ratios (ϕ) ranging from f 0.8 to 1.4, and ammonia mole fraction (X<sub>NH3</sub>) from 0 to 0.6. The addition of 2MF was found to substantially enhance the combustion characteristics of ammonia. Increasing the ammonia content up to X<sub>NH3</sub>=0.6 significantly reduces the S<sub>L</sub> of 2MF/air flame speed, with a maximum reduction of approximately 20 cm/s observed at ϕ = 1.1. L<sub>b</sub> notably decreases with increasing ϕ, while the effect of X<sub>NH3</sub> varies with ϕ. A flame instability assessment was performed by determining critical Peclet number and Karlovitz number at the onset of flame instability. The temperature and pressure dependences of S<sub>L</sub> were obtained experimentally. The normalized flame speed S<sub>L</sub>/S<sub>L0</sub> versus X<sub>NH3</sub> follows a consistent trend across different pressures and temperatures. Based on these findings, an empirical correlation was developed to predict S<sub>L</sub> of 2MF/NH<sub>3</sub>/air blends under various conditions of P, T, ϕ and X<sub>NH3</sub>. A composite chemical kinetic model of 2MF/NH<sub>3</sub>/air reliably predicted S<sub>L</sub> obtained in this work. Sensitivity and reaction path analyses indicated that S<sub>L</sub> of 2MF/NH<sub>3</sub>/air blends is governed by the oxidation of small hydrocarbon and amine molecules, which compete for the same radical pool. Furthermore, when ammonia content is high (X<sub>NH3</sub>=0.5–1.0), blending ammonia with 2MF provides greater enhancement than blending ammonia with hydrogen or methane.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114769"},"PeriodicalIF":6.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922304","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}
The oxidation of methylamine sensitized by NO and NO2 was investigated in an atmospheric-pressure jet-stirred reactor using a combination of three different diagnostic techniques, covering temperatures of 575–1300 K and equivalence ratios of 0.2–1.0. HCN appeared as the primary intermediate, and N2O and N2 were the main nitrogenous products. It was found that the addition of NO greatly facilitated methylamine oxidation at low temperatures, but the promoting effect was almost independent of NO concentration. And the methylamine reactivity became more sensitive to inlet oxygen concentration in the presence of NO. The addition of NO2 enhanced methylamine oxidation kinetics over the investigated temperature range, which was hardly affected by the inlet NO2 and oxygen concentrations. For the first time, the rate coefficients of all product channels of the reaction CH3NH2 + NO2 were calculated at the CCSD(T)/aug-cc-pVTZ//M062X/aug-cc-pVDZ level for better interpreting the methylamine-NO2 interaction. A chemical kinetic model with inclusion of the calculation results was developed. The model yielded satisfactory predictions for the evolution profiles of methylamine, oxygen and most major products, but it over-predicted the concentrations of HCN and NO at intermediate temperatures. Finally, the mechanisms of NO and NO2 sensitization on methylamine oxidation were elucidated and main reaction pathways were identified through kinetic analyses.
{"title":"Exploring the sensitizing effects of NO and NO2 on methylamine oxidation","authors":"Guoxing Li , Shaoguang Zhang , Yue Chen , Qian Zhao","doi":"10.1016/j.combustflame.2026.114768","DOIUrl":"10.1016/j.combustflame.2026.114768","url":null,"abstract":"<div><div>The oxidation of methylamine sensitized by NO and NO<sub>2</sub> was investigated in an atmospheric-pressure jet-stirred reactor using a combination of three different diagnostic techniques, covering temperatures of 575–1300 K and equivalence ratios of 0.2–1.0. HCN appeared as the primary intermediate, and N<sub>2</sub>O and N<sub>2</sub> were the main nitrogenous products. It was found that the addition of NO greatly facilitated methylamine oxidation at low temperatures, but the promoting effect was almost independent of NO concentration. And the methylamine reactivity became more sensitive to inlet oxygen concentration in the presence of NO. The addition of NO<sub>2</sub> enhanced methylamine oxidation kinetics over the investigated temperature range, which was hardly affected by the inlet NO<sub>2</sub> and oxygen concentrations. For the first time, the rate coefficients of all product channels of the reaction CH<sub>3</sub>NH<sub>2</sub> + NO<sub>2</sub> were calculated at the CCSD(T)/aug-cc-pVTZ//M062X/aug-cc-pVDZ level for better interpreting the methylamine-NO<sub>2</sub> interaction. A chemical kinetic model with inclusion of the calculation results was developed. The model yielded satisfactory predictions for the evolution profiles of methylamine, oxygen and most major products, but it over-predicted the concentrations of HCN and NO at intermediate temperatures. Finally, the mechanisms of NO and NO<sub>2</sub> sensitization on methylamine oxidation were elucidated and main reaction pathways were identified through kinetic analyses.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114768"},"PeriodicalIF":6.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922302","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}
Pub Date : 2026-01-08DOI: 10.1016/j.combustflame.2026.114767
Yingjian Wang , Lixiang Meng , Jundong Zhang , Daoyi Lu , Dong Chen , Longde Wang , Zhaoxia Huang
A comprehensive investigation of the reaction mechanism between NH2 and large molecules is essential for establishing high-fidelity fuel/NH3 combustion kinetics models. To this end, the potential energy surfaces of H-abstraction reactions between NH2 and toluene reference fuel (n-heptane, isooctane, and toluene) were explored at the DLPNO-CCSD(T1)-F12/cc-pVTZ-F12//M06–2X-D3/6–311++G(d,p) level. Rate coefficients for all reaction channels were calculated using canonical variational transition state theory, with particular emphasis on the effects of recrossing effects, tunneling effects, and multi-structural torsional anharmonicity. It was found that all reaction channels in n-C7H16/i-C8H18 + NH2 exhibit significant multi-structural torsional effects, significantly enhancing the rate coefficients. Moreover, in C7H8 + NH2, the reaction channel involving H-abstraction from the para position of the benzene ring reaches a branching ratio of 26.3% at 1500 K, emphasizing the importance of H-abstraction from the aromatic ring. By fitting the rate coefficients to Arrhenius expressions and implementing them into an TRF/NH3 kinetic model, the influence of the TRF + NH2 mechanism on ignition delay times and laminar flame speeds was assessed, thereby clarifying its impact on combustion characteristics. This work contributes to improving the predictive accuracy of TRF/NH3 combustion kinetic models.
{"title":"Theoretical and detailed kinetic investigation of H-abstraction by NH2 from toluene reference fuel","authors":"Yingjian Wang , Lixiang Meng , Jundong Zhang , Daoyi Lu , Dong Chen , Longde Wang , Zhaoxia Huang","doi":"10.1016/j.combustflame.2026.114767","DOIUrl":"10.1016/j.combustflame.2026.114767","url":null,"abstract":"<div><div>A comprehensive investigation of the reaction mechanism between NH<sub>2</sub> and large molecules is essential for establishing high-fidelity fuel/NH<sub>3</sub> combustion kinetics models. To this end, the potential energy surfaces of H-abstraction reactions between NH<sub>2</sub> and toluene reference fuel (<em>n</em>-heptane, isooctane, and toluene) were explored at the DLPNO-CCSD(T1)-F12/cc-pVTZ-F12//M06–2X-D3/6–311++<em>G</em>(d,p) level. Rate coefficients for all reaction channels were calculated using canonical variational transition state theory, with particular emphasis on the effects of recrossing effects, tunneling effects, and multi-structural torsional anharmonicity. It was found that all reaction channels in <em>n</em>-C<sub>7</sub>H<sub>16</sub>/<em>i</em>-C<sub>8</sub>H<sub>18</sub> + NH<sub>2</sub> exhibit significant multi-structural torsional effects, significantly enhancing the rate coefficients. Moreover, in C<sub>7</sub>H<sub>8</sub> + NH<sub>2</sub>, the reaction channel involving H-abstraction from the para position of the benzene ring reaches a branching ratio of 26.3% at 1500 K, emphasizing the importance of H-abstraction from the aromatic ring. By fitting the rate coefficients to Arrhenius expressions and implementing them into an TRF/NH<sub>3</sub> kinetic model, the influence of the TRF + NH<sub>2</sub> mechanism on ignition delay times and laminar flame speeds was assessed, thereby clarifying its impact on combustion characteristics. This work contributes to improving the predictive accuracy of TRF/NH<sub>3</sub> combustion kinetic models.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114767"},"PeriodicalIF":6.2,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922301","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}
Pub Date : 2026-01-07DOI: 10.1016/j.combustflame.2025.114758
Mohammad Adib, Sina Kazemi, M. Reza Kholghy
<div><div>A computational tool, Omnisoot, was developed utilizing the chemical kinetics capabilities of Cantera to model the formation of carbonaceous nanoparticles, such as soot and Carbon Black (CB), from the reactions of gaseous hydrocarbons. Omnisoot integrates constant volume, constant pressure, perfectly stirred, and plug flow reactor models with four inception models from the literature, as well as two population balance models: a monodisperse model and a sectional model. This package serves as an integrated process design tool to predict soot mass, morphology, and composition under varying process conditions. The modeling approach accounts for soot inception, surface growth, and oxidation, coupled with detailed gas-phase chemistry, to close the mass and energy balances of the gas-particle system; subsequently, soot and gas-phase chemistry are linked to the particle dynamics models that consider the evolving fractal-like structure of soot agglomerates. The developed tool was employed to highlight the similarities and differences among the implemented inception models in predicting soot mass, morphology, and size distribution for three use-cases: methane pyrolysis in a shock tube, ethylene pyrolysis in a flow reactor, and ethylene combustion in a perfectly stirred reactor. The simulations of 5% <span><math><msub><mrow><mi>CH</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> pyrolysis in shock-tube with short residence times (<span><math><mrow><mo>≈</mo><mn>1</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>ms</mi></mrow></math></span>) demonstrated that multiple combinations of inception and surface growth rates minimized the prediction error for carbon yield but led to markedly different morphologies, emphasizing the need for measured data on soot morphology to constrain inception and surface growth rates. The comparison of simulation results in a pyrolysis flow reactor at three different flow rates suggested that only irreversible models can predict bimodality in particle size distribution.</div><div><strong>Novelty and significance statement</strong></div><div>In this research, Omnisoot is introduced as a comprehensive modeling platform for the detailed description of carbonaceous nanoparticles. This tool integrates constant volume, constant pressure, perfectly stirred, and plug flow reactor models with four inception models and two population balance models. A step-by-step validation approach was followed to ensure the reliability of all sub-models. Elemental mass balances for carbon and hydrogen were assessed; the importance of soot sensible and formation enthalpy was highlighted to close the energy balance of the gas-particle system. A new inception model based on E-Bridge bond formation was coupled with gas chemistry and particle dynamics to simulate soot formation. Unlike previous studies, the fundamental differences and similarities between the implemented inception models were investigated when the inception and surface growth r
{"title":"Omnisoot: a process design package for gas-phase synthesis of carbonaceous nanoparticles","authors":"Mohammad Adib, Sina Kazemi, M. Reza Kholghy","doi":"10.1016/j.combustflame.2025.114758","DOIUrl":"10.1016/j.combustflame.2025.114758","url":null,"abstract":"<div><div>A computational tool, Omnisoot, was developed utilizing the chemical kinetics capabilities of Cantera to model the formation of carbonaceous nanoparticles, such as soot and Carbon Black (CB), from the reactions of gaseous hydrocarbons. Omnisoot integrates constant volume, constant pressure, perfectly stirred, and plug flow reactor models with four inception models from the literature, as well as two population balance models: a monodisperse model and a sectional model. This package serves as an integrated process design tool to predict soot mass, morphology, and composition under varying process conditions. The modeling approach accounts for soot inception, surface growth, and oxidation, coupled with detailed gas-phase chemistry, to close the mass and energy balances of the gas-particle system; subsequently, soot and gas-phase chemistry are linked to the particle dynamics models that consider the evolving fractal-like structure of soot agglomerates. The developed tool was employed to highlight the similarities and differences among the implemented inception models in predicting soot mass, morphology, and size distribution for three use-cases: methane pyrolysis in a shock tube, ethylene pyrolysis in a flow reactor, and ethylene combustion in a perfectly stirred reactor. The simulations of 5% <span><math><msub><mrow><mi>CH</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> pyrolysis in shock-tube with short residence times (<span><math><mrow><mo>≈</mo><mn>1</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>ms</mi></mrow></math></span>) demonstrated that multiple combinations of inception and surface growth rates minimized the prediction error for carbon yield but led to markedly different morphologies, emphasizing the need for measured data on soot morphology to constrain inception and surface growth rates. The comparison of simulation results in a pyrolysis flow reactor at three different flow rates suggested that only irreversible models can predict bimodality in particle size distribution.</div><div><strong>Novelty and significance statement</strong></div><div>In this research, Omnisoot is introduced as a comprehensive modeling platform for the detailed description of carbonaceous nanoparticles. This tool integrates constant volume, constant pressure, perfectly stirred, and plug flow reactor models with four inception models and two population balance models. A step-by-step validation approach was followed to ensure the reliability of all sub-models. Elemental mass balances for carbon and hydrogen were assessed; the importance of soot sensible and formation enthalpy was highlighted to close the energy balance of the gas-particle system. A new inception model based on E-Bridge bond formation was coupled with gas chemistry and particle dynamics to simulate soot formation. Unlike previous studies, the fundamental differences and similarities between the implemented inception models were investigated when the inception and surface growth r","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114758"},"PeriodicalIF":6.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922300","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}
Pub Date : 2026-01-07DOI: 10.1016/j.combustflame.2026.114772
Mayank Pandey, Krishnakant Agrawal, Anjan Ray
<div><div>Hydrogen storage at low temperatures for its commercial transport and utilization has safety concerns associated with its accidental leakage and subsequent combustion. Apart from flammability limits, understanding flame propagation and acceleration at such conditions, including intrinsic flame instabilities, is essential to assess fire and pressure rise risks. In this work, two-dimensional simulations of freely propagating H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air flames at low temperature and atmospheric pressure are carried out with detailed chemistry and transport. As the flame density ratio at low temperature (100K) increases approximately three times compared to room temperature (300K), it is expected to result in strong Darrieus–Landau instability. Our parametric analysis reveals increased growth rates of the harmonically perturbed flame front at 100K compared to 300K for lean-to-rich H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air flames, with a pronounced increase near lean conditions due to thermodiffusive effects. The normalized consumption speed is also higher for low temperatures due to substantial flame wrinkling and an increased flame surface area resulting from long, finger-like structures. The domain dependency of the large-scale finger-type structure is expected in the literature for flames with a high density ratio. This study demonstrates such behavior for low-temperature flames using domain sizes up to 300 times the thickness of the laminar flame. To explore the contribution of thermodiffusive instabilities, a unity Lewis number approximation was used to deliberately suppress these instabilities, resulting in an appreciable reduction in growth rate and overall consumption speed, even at high density ratios. Overall, the present work suggests that H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air mixtures at low temperatures pose a critical safety concern due to a synergistic interaction between hydrodynamic and thermo-diffusive instabilities.</div><div><strong>Novelty and significance statement</strong></div><div>The novelty of the present work lies in its numerical investigations of lean-to-rich hydrogen-air flames at low temperatures (100K) in the context of intrinsic flame instability in a two-dimensional domain. Strong Darrieus–Landau instability is observed at low temperature due to high density ratios, resulting in a long finger-like structure. The synergistic interaction of hydrodynamic and thermodiffusive instability is demonstrated for the first time at low temperatures, to the best of the author’s knowledge. The contributions from the thermodiffusive effect at the small scale and the Darrieus–Landau effect at the hydrodynamic length scale result in elongation of the flame and subsequent increases in flame surface area and overall consumption speed. The flame structure at 100K differs from that at 300K for
{"title":"Intrinsically unstable laminar premixed H2/air flames at low temperature","authors":"Mayank Pandey, Krishnakant Agrawal, Anjan Ray","doi":"10.1016/j.combustflame.2026.114772","DOIUrl":"10.1016/j.combustflame.2026.114772","url":null,"abstract":"<div><div>Hydrogen storage at low temperatures for its commercial transport and utilization has safety concerns associated with its accidental leakage and subsequent combustion. Apart from flammability limits, understanding flame propagation and acceleration at such conditions, including intrinsic flame instabilities, is essential to assess fire and pressure rise risks. In this work, two-dimensional simulations of freely propagating H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air flames at low temperature and atmospheric pressure are carried out with detailed chemistry and transport. As the flame density ratio at low temperature (100K) increases approximately three times compared to room temperature (300K), it is expected to result in strong Darrieus–Landau instability. Our parametric analysis reveals increased growth rates of the harmonically perturbed flame front at 100K compared to 300K for lean-to-rich H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air flames, with a pronounced increase near lean conditions due to thermodiffusive effects. The normalized consumption speed is also higher for low temperatures due to substantial flame wrinkling and an increased flame surface area resulting from long, finger-like structures. The domain dependency of the large-scale finger-type structure is expected in the literature for flames with a high density ratio. This study demonstrates such behavior for low-temperature flames using domain sizes up to 300 times the thickness of the laminar flame. To explore the contribution of thermodiffusive instabilities, a unity Lewis number approximation was used to deliberately suppress these instabilities, resulting in an appreciable reduction in growth rate and overall consumption speed, even at high density ratios. Overall, the present work suggests that H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/air mixtures at low temperatures pose a critical safety concern due to a synergistic interaction between hydrodynamic and thermo-diffusive instabilities.</div><div><strong>Novelty and significance statement</strong></div><div>The novelty of the present work lies in its numerical investigations of lean-to-rich hydrogen-air flames at low temperatures (100K) in the context of intrinsic flame instability in a two-dimensional domain. Strong Darrieus–Landau instability is observed at low temperature due to high density ratios, resulting in a long finger-like structure. The synergistic interaction of hydrodynamic and thermodiffusive instability is demonstrated for the first time at low temperatures, to the best of the author’s knowledge. The contributions from the thermodiffusive effect at the small scale and the Darrieus–Landau effect at the hydrodynamic length scale result in elongation of the flame and subsequent increases in flame surface area and overall consumption speed. The flame structure at 100K differs from that at 300K for ","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114772"},"PeriodicalIF":6.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922303","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}
Pub Date : 2026-01-05DOI: 10.1016/j.combustflame.2026.114766
Guangyao Yang, Aiwu Fan
It is difficult to obtain stationary flames over a wide operating range for mesoscale combustors filled with homogeneous porous media. In the present work, we first experimentally explored flame stability limits of stoichiometric n-C4H10/air mixtures in a quartz tube (ID=6 mm) inserted with T-shaped metal foam of various protruding lengths. Three flame modes, namely, immerged planar flame, immerged convex flame, and surface flame were observed. The maximum blowout limit reached 1.05 m/s, which is larger than twice the counterpart of inserting cylindrical porous media (i.e., 0.5 m/s). Meanwhile, the extinction limit remained almost unchanged. Numerical analysis demonstrated that part of gas mixture escaped from the protruding part into the annular free space due to larger flow resistance in the porous media, which created a low-velocity zone inside the protruding part to stabilize the flame root. Furthermore, the heat recirculation effect via porous media was enhanced owing to the existence of immerged flame. Finally, it was revealed that the thermal interaction between flame and the protruding part of porous media provided a spontaneous adjustment function to sustain the flame root over a wide range of inlet velocity.
{"title":"Experimental and numerical study on flame stability limits of a mesoscale combustor filled with T-shaped porous media","authors":"Guangyao Yang, Aiwu Fan","doi":"10.1016/j.combustflame.2026.114766","DOIUrl":"10.1016/j.combustflame.2026.114766","url":null,"abstract":"<div><div>It is difficult to obtain stationary flames over a wide operating range for mesoscale combustors filled with homogeneous porous media. In the present work, we first experimentally explored flame stability limits of stoichiometric n-C<sub>4</sub>H<sub>10</sub>/air mixtures in a quartz tube (ID=6 mm) inserted with T-shaped metal foam of various protruding lengths. Three flame modes, namely, immerged planar flame, immerged convex flame, and surface flame were observed. The maximum blowout limit reached 1.05 m/s, which is larger than twice the counterpart of inserting cylindrical porous media (i.e., 0.5 m/s). Meanwhile, the extinction limit remained almost unchanged. Numerical analysis demonstrated that part of gas mixture escaped from the protruding part into the annular free space due to larger flow resistance in the porous media, which created a low-velocity zone inside the protruding part to stabilize the flame root. Furthermore, the heat recirculation effect via porous media was enhanced owing to the existence of immerged flame. Finally, it was revealed that the thermal interaction between flame and the protruding part of porous media provided a spontaneous adjustment function to sustain the flame root over a wide range of inlet velocity.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"285 ","pages":"Article 114766"},"PeriodicalIF":6.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922384","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}
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