Pub Date : 2026-04-01Epub Date: 2026-01-17DOI: 10.1016/j.combustflame.2026.114804
Daoguan Ning, Dongwon Ka, Andy Huu Huynh, Yuzhe Li, Xiaolin Zheng
<div><div>Ignition and combustion dynamics of boron/hydroxyl-terminated polybutadiene (B-HTPB) composites are central to propulsion performance, yet quantitative information on ignition temperature and burn rate at engine-relevant high heating rates (<span><math><mo>∼</mo></math></span>1000<!--> <!-->K/s) remains limited. In this work, we quantify the ignition temperature and combustion dynamics of individual B-HTPB microparticles using a custom-built drop-tube-like reactor with a pre-defined vertical temperature profile, achieving high heating rates (<span><math><mo>∼</mo></math></span>250–1500<!--> <!-->K/s). The ignition temperature of B-HTPB particles decreases slightly from 1005<!--> <!-->K to 975<!--> <!-->K as the particle size increases from approximately <span><math><mrow><mn>25</mn><mspace></mspace><mi>μ</mi></mrow></math></span>m to <span><math><mrow><mn>100</mn><mspace></mspace><mi>μ</mi></mrow></math></span>m and closely matches that of pure HTPB microparticles (950<!--> <!-->K–1000<!--> <!-->K). This indicates that, under rapid heating, ignition of B-HTPB is governed by the condensed-phase decomposition of HTPB and gas-phase reactions of HTPB pyrolysis products rather than the heterogeneous boron oxidation, for which the kinetics are too slow to contribute. Time-resolved flame emission intensity and high-speed imaging reveal two distinct combustion stages for B-HTPB: an initial volatile-driven gas-phase flame followed by a phase characterized by ejection and burning of boron particles. The first stage accounts for approximately 64% of the total burn time. The burn time of B-HTPB follows an empirical scaling (<span><math><mrow><msub><mrow><mi>t</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>=</mo><mn>2</mn><mo>.</mo><mn>1</mn><msubsup><mrow><mi>d</mi></mrow><mrow><mi>p</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>63</mn></mrow></msubsup></mrow></math></span>, with <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span> in ms and <span><math><msub><mrow><mi>d</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> in <span><math><mi>μ</mi></math></span>m), indicating that surface pyrolysis of HTPB likely limits overall B-HTPB combustion. Using the measured particle burn time, the regression rate of B-HTPB burning in heated air is estimated as 0.09<!--> <!-->mm/s, comparable to those measured in counterflow experiments. These results provide quantitative information on ignition temperature and staged-combustion of B-HTPB composites at realistic heating rates and offer benchmarks for validating reaction-kinetic and multi-physics models of B-HTPB composite fuels.</div><div><strong>Novelty and significance statement</strong></div><div>This work, for the first time, quantitatively determines the ignition temperature of B-HTPB composites under high heating rates representative of realistic combustion scenarios. The results help to identify the controlling mechanism of the composite particle ignition. High-speed imagi
{"title":"Ignition temperature and combustion dynamics of B-HTPB composite microparticles","authors":"Daoguan Ning, Dongwon Ka, Andy Huu Huynh, Yuzhe Li, Xiaolin Zheng","doi":"10.1016/j.combustflame.2026.114804","DOIUrl":"10.1016/j.combustflame.2026.114804","url":null,"abstract":"<div><div>Ignition and combustion dynamics of boron/hydroxyl-terminated polybutadiene (B-HTPB) composites are central to propulsion performance, yet quantitative information on ignition temperature and burn rate at engine-relevant high heating rates (<span><math><mo>∼</mo></math></span>1000<!--> <!-->K/s) remains limited. In this work, we quantify the ignition temperature and combustion dynamics of individual B-HTPB microparticles using a custom-built drop-tube-like reactor with a pre-defined vertical temperature profile, achieving high heating rates (<span><math><mo>∼</mo></math></span>250–1500<!--> <!-->K/s). The ignition temperature of B-HTPB particles decreases slightly from 1005<!--> <!-->K to 975<!--> <!-->K as the particle size increases from approximately <span><math><mrow><mn>25</mn><mspace></mspace><mi>μ</mi></mrow></math></span>m to <span><math><mrow><mn>100</mn><mspace></mspace><mi>μ</mi></mrow></math></span>m and closely matches that of pure HTPB microparticles (950<!--> <!-->K–1000<!--> <!-->K). This indicates that, under rapid heating, ignition of B-HTPB is governed by the condensed-phase decomposition of HTPB and gas-phase reactions of HTPB pyrolysis products rather than the heterogeneous boron oxidation, for which the kinetics are too slow to contribute. Time-resolved flame emission intensity and high-speed imaging reveal two distinct combustion stages for B-HTPB: an initial volatile-driven gas-phase flame followed by a phase characterized by ejection and burning of boron particles. The first stage accounts for approximately 64% of the total burn time. The burn time of B-HTPB follows an empirical scaling (<span><math><mrow><msub><mrow><mi>t</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>=</mo><mn>2</mn><mo>.</mo><mn>1</mn><msubsup><mrow><mi>d</mi></mrow><mrow><mi>p</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>63</mn></mrow></msubsup></mrow></math></span>, with <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span> in ms and <span><math><msub><mrow><mi>d</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span> in <span><math><mi>μ</mi></math></span>m), indicating that surface pyrolysis of HTPB likely limits overall B-HTPB combustion. Using the measured particle burn time, the regression rate of B-HTPB burning in heated air is estimated as 0.09<!--> <!-->mm/s, comparable to those measured in counterflow experiments. These results provide quantitative information on ignition temperature and staged-combustion of B-HTPB composites at realistic heating rates and offer benchmarks for validating reaction-kinetic and multi-physics models of B-HTPB composite fuels.</div><div><strong>Novelty and significance statement</strong></div><div>This work, for the first time, quantitatively determines the ignition temperature of B-HTPB composites under high heating rates representative of realistic combustion scenarios. The results help to identify the controlling mechanism of the composite particle ignition. High-speed imagi","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114804"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976373","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 : 2026-04-01Epub Date: 2026-01-30DOI: 10.1016/j.combustflame.2026.114801
Qiuhong Wang , He Zhu , Jun Deng , Zhenmin Luo , Wei Gao , Xiangrong Liu , Qingfeng Wang , Yifei Liu , Siru Wang
Propane can mix with air in storage tanks or pipes during transport and use, causing gas clouds in industrial facilities. At high temperatures or from ignition, gas clouds can explode. Explosion suppressants for propane must be researched for industrial safety. In a 20 L spherical explosion experimental setup, propane explosion pressure and limits under CO2, ABC powder, and CO2/ABC gas-solid combination suppressants were examined. Explosion suppression patterns for single-phase and combination suppressants were studied. Linear regression and density functional theory (DFT) calculations revealed the composite suppressant's two components’ major impact on explosive parameters. The results showed that 9% CO2 with 150 g/m3 ABC powder or 15% CO2 with 100 g/m3 ABC powder mitigates propane explosions. CO2 physically diminishes the pressure differential pre- and post-explosion, largely influencing the peak pressure. By sequestering critical free radicals (O2, H·, OH·, CH3·), ABC powder disrupts chain reactions and reduces explosion intensity, significantly affecting maximum pressure rise rate. These findings provide a theoretical framework for enhancing the CO2/ABC powder mass ratio and real-time industrial injection concentration adjustment.
{"title":"Study on inhibition mechanisms of CO2/ABC gas-solid compound suppressant on propane explosion using experiments and DFT method","authors":"Qiuhong Wang , He Zhu , Jun Deng , Zhenmin Luo , Wei Gao , Xiangrong Liu , Qingfeng Wang , Yifei Liu , Siru Wang","doi":"10.1016/j.combustflame.2026.114801","DOIUrl":"10.1016/j.combustflame.2026.114801","url":null,"abstract":"<div><div>Propane can mix with air in storage tanks or pipes during transport and use, causing gas clouds in industrial facilities. At high temperatures or from ignition, gas clouds can explode. Explosion suppressants for propane must be researched for industrial safety. In a 20 L spherical explosion experimental setup, propane explosion pressure and limits under CO<sub>2</sub>, ABC powder, and CO<sub>2</sub>/ABC gas-solid combination suppressants were examined. Explosion suppression patterns for single-phase and combination suppressants were studied. Linear regression and density functional theory (DFT) calculations revealed the composite suppressant's two components’ major impact on explosive parameters. The results showed that 9% CO<sub>2</sub> with 150 g/m<sup>3</sup> ABC powder or 15% CO<sub>2</sub> with 100 g/m<sup>3</sup> ABC powder mitigates propane explosions. CO<sub>2</sub> physically diminishes the pressure differential pre- and post-explosion, largely influencing the peak pressure. By sequestering critical free radicals (O<sub>2</sub>, H·, OH·, CH<sub>3</sub>·), ABC powder disrupts chain reactions and reduces explosion intensity, significantly affecting maximum pressure rise rate. These findings provide a theoretical framework for enhancing the CO<sub>2</sub>/ABC powder mass ratio and real-time industrial injection concentration adjustment.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114801"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075227","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 : 2026-04-01Epub Date: 2026-02-12DOI: 10.1016/j.combustflame.2026.114866
Yifan Xu , Runze Mao , Zhi X. Chen , Lukas Berger , Michael Gauding , Heinz Pitsch
<div><div>This study investigates the use of deep learning for modelling sub-filter probability density functions (PDFs) in lean hydrogen flames with thermodiffusive instability. The intrinsic instability presents a considerable challenge in numerical models for lean hydrogen/air flames, leading to significant alterations in flame dynamics, heat release rates, and flame speeds. A data-driven approach is explored to analyse the filtered density functions (FDFs) in turbulence-chemistry interactions, as traditional tabulation approaches that use presumed sub-filter PDFs for LES, face challenges in accurately representing the correct statistical behaviour. In this work, deep neural networks (DNN) are trained and optimized using the datasets from large-scale DNS of a three-dimensional premixed lean hydrogen/air flame in a turbulent slot burner conducted by Berger et al. (Combust. Flame 244, 2022). The classical presumed beta-function model is employed as a baseline to give a comparison with the DNS data and the DNN model. The filtered density functions (FDFs) in the considered case show a complex shape with strongly correlated random variables in the reaction zone, which is difficult to capture using presumed beta-function models tested in this paper. The DNN model proves to be effective in tackling this complex problem, with its predictions showing excellent agreement with the DNS data and outperforming the beta-function PDF with all filter sizes. Furthermore, an <em>a priori</em> assessment is carried out for the filtered reaction rate closure and the DNN model also exhibits outstanding precision. Further, the DNN model’s generalization capability is then investigated at two levels: (1) different filter kernels and multiple filter sizes are assessed and (2) the model is applied to a <em>High Ka</em> test case, which is entirely unseen during training. Models trained with different filter kernels and multiple filter sizes maintain consistent accuracy, revealing the potential for <em>a posteriori</em> simulations. When evaluating on the unseen <em>High Ka</em> case, it is demonstrated that out-of-sample testing provides highly improved results compared with the beta-function model, proving the DNN model’s robust generalizability. Furthermore, a few-shot fine-tuning strategy is proposed to further enhance predicting accuracy, showing significant improvement in the generalization case with only a few percent of new data included. This opens new possibilities for practical applications where sparse observation data such as experimental measurements are available for model training.</div><div><strong>Novelty and significance statement</strong></div><div>The novelty of this research is introducing an innovative deep learning framework for modelling sub-filter probability density functions in lean hydrogen flames with thermodiffusive instability, addressing a critical challenge in turbulent combustion simulation. The trained DNN model accurately captures th
{"title":"Generalizable deep learning for sub-filter PDF of thermo-diffusively unstable lean hydrogen flames at varying Ka numbers","authors":"Yifan Xu , Runze Mao , Zhi X. Chen , Lukas Berger , Michael Gauding , Heinz Pitsch","doi":"10.1016/j.combustflame.2026.114866","DOIUrl":"10.1016/j.combustflame.2026.114866","url":null,"abstract":"<div><div>This study investigates the use of deep learning for modelling sub-filter probability density functions (PDFs) in lean hydrogen flames with thermodiffusive instability. The intrinsic instability presents a considerable challenge in numerical models for lean hydrogen/air flames, leading to significant alterations in flame dynamics, heat release rates, and flame speeds. A data-driven approach is explored to analyse the filtered density functions (FDFs) in turbulence-chemistry interactions, as traditional tabulation approaches that use presumed sub-filter PDFs for LES, face challenges in accurately representing the correct statistical behaviour. In this work, deep neural networks (DNN) are trained and optimized using the datasets from large-scale DNS of a three-dimensional premixed lean hydrogen/air flame in a turbulent slot burner conducted by Berger et al. (Combust. Flame 244, 2022). The classical presumed beta-function model is employed as a baseline to give a comparison with the DNS data and the DNN model. The filtered density functions (FDFs) in the considered case show a complex shape with strongly correlated random variables in the reaction zone, which is difficult to capture using presumed beta-function models tested in this paper. The DNN model proves to be effective in tackling this complex problem, with its predictions showing excellent agreement with the DNS data and outperforming the beta-function PDF with all filter sizes. Furthermore, an <em>a priori</em> assessment is carried out for the filtered reaction rate closure and the DNN model also exhibits outstanding precision. Further, the DNN model’s generalization capability is then investigated at two levels: (1) different filter kernels and multiple filter sizes are assessed and (2) the model is applied to a <em>High Ka</em> test case, which is entirely unseen during training. Models trained with different filter kernels and multiple filter sizes maintain consistent accuracy, revealing the potential for <em>a posteriori</em> simulations. When evaluating on the unseen <em>High Ka</em> case, it is demonstrated that out-of-sample testing provides highly improved results compared with the beta-function model, proving the DNN model’s robust generalizability. Furthermore, a few-shot fine-tuning strategy is proposed to further enhance predicting accuracy, showing significant improvement in the generalization case with only a few percent of new data included. This opens new possibilities for practical applications where sparse observation data such as experimental measurements are available for model training.</div><div><strong>Novelty and significance statement</strong></div><div>The novelty of this research is introducing an innovative deep learning framework for modelling sub-filter probability density functions in lean hydrogen flames with thermodiffusive instability, addressing a critical challenge in turbulent combustion simulation. The trained DNN model accurately captures th","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114866"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184814","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 : 2026-04-01Epub Date: 2026-02-06DOI: 10.1016/j.combustflame.2026.114854
Yu Yang , Sihang Rao , Yihao Tang , Shu Zheng , Wang Han , Lijun Yang
Increasing oxygen indices (OI) provides a feasible solution to enhance the intermediate soot loading, which can improve the radiative heat transfer and combustion efficiencies in the combustion of NH3 blending fuels. However, this strategy introduces challenges for soot prediction due to the competing effects of high OI (promoting soot formation) and NH3 (suppressing soot formation). In this context, it remains unclear whether OI can alter the influence of NH3 on the soot formation. This study experimentally and numerically investigated the effects of NH3 on soot nucleation, condensation, HACA (hydrogen-abstraction-carbon-addition) surface growth, and oxidation processes in C2H4 co-flow diffusion flame under various OI conditions ranging from 21% to 27%. The results showed that increasing OI can weaken the suppression impact of NH3 on the soot formation in the flame centerline region but enhance that in the flame wing region. The former was attributed to a larger decrease in the soot nucleation and condensation processes caused by NH3 addition at 27% OI compared with 21% OI. Additionally, compared to the C2H4/21%OI flame, the C2H4/27%OI flame exhibited higher peak flame temperatures following NH3 addition. This led to an enhanced decomposition rate of C5H5 through the reaction of C5H5=C3H3+C2H2, partially counteracting the chemical suppression of NH3 on the formation of C2H2. As a result, the inhibitory effect of NH3 on the conversion of C2H2 to A1 (benzene) was attenuated in the C2H4/27% OI flame relative to the C2H4/21% OI flame, leading to a smaller reduction in soot nucleation and condensation rates. In contrast, in the flame wing region, the NH3 addition led to a more substantial increase in the forward rates of H + O2OH+O and O + H2O=2OH under the 27% OI condition, thereby enhancing the oxidation rate via OH radical and amplifying the suppression effect of NH3 on the soot formation in the flame wing region.
{"title":"Soot formation in a laminar co-flow C2H4-NH3 diffusion flame at different oxygen indices","authors":"Yu Yang , Sihang Rao , Yihao Tang , Shu Zheng , Wang Han , Lijun Yang","doi":"10.1016/j.combustflame.2026.114854","DOIUrl":"10.1016/j.combustflame.2026.114854","url":null,"abstract":"<div><div>Increasing oxygen indices (OI) provides a feasible solution to enhance the intermediate soot loading, which can improve the radiative heat transfer and combustion efficiencies in the combustion of NH<sub>3</sub> blending fuels. However, this strategy introduces challenges for soot prediction due to the competing effects of high OI (promoting soot formation) and NH<sub>3</sub> (suppressing soot formation). In this context, it remains unclear whether OI can alter the influence of NH<sub>3</sub> on the soot formation. This study experimentally and numerically investigated the effects of NH<sub>3</sub> on soot nucleation, condensation, HACA (hydrogen-abstraction-carbon-addition) surface growth, and oxidation processes in C<sub>2</sub>H<sub>4</sub> co-flow diffusion flame under various OI conditions ranging from 21% to 27%. The results showed that increasing OI can weaken the suppression impact of NH<sub>3</sub> on the soot formation in the flame centerline region but enhance that in the flame wing region. The former was attributed to a larger decrease in the soot nucleation and condensation processes caused by NH<sub>3</sub> addition at 27% OI compared with 21% OI. Additionally, compared to the C<sub>2</sub>H<sub>4</sub>/21%OI flame, the C<sub>2</sub>H<sub>4</sub>/27%OI flame exhibited higher peak flame temperatures following NH<sub>3</sub> addition. This led to an enhanced decomposition rate of C<sub>5</sub>H<sub>5</sub> through the reaction of C<sub>5</sub>H<sub>5</sub>=C<sub>3</sub>H<sub>3</sub>+C<sub>2</sub>H<sub>2</sub>, partially counteracting the chemical suppression of NH<sub>3</sub> on the formation of C<sub>2</sub>H<sub>2</sub>. As a result, the inhibitory effect of NH<sub>3</sub> on the conversion of C<sub>2</sub>H<sub>2</sub> to A1 (benzene) was attenuated in the C<sub>2</sub>H<sub>4</sub>/27% OI flame relative to the C<sub>2</sub>H<sub>4</sub>/21% OI flame, leading to a smaller reduction in soot nucleation and condensation rates. In contrast, in the flame wing region, the NH<sub>3</sub> addition led to a more substantial increase in the forward rates of <em>H</em> + O<sub>2</sub><img>OH+<em>O</em> and <em>O</em> + H<sub>2</sub>O=2OH under the 27% OI condition, thereby enhancing the oxidation rate via OH radical and amplifying the suppression effect of NH<sub>3</sub> on the soot formation in the flame wing region.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114854"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185194","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 : 2026-04-01Epub Date: 2026-01-31DOI: 10.1016/j.combustflame.2026.114844
Song He, Fei Xie, Haibo Zhao
Vapor-fed flame aerosol synthesis is a powerful and versatile technique for the large-scale production of nanomaterials. However, further improvements are still in great demand for enhancing rapidly mixed combustion of non-premixed fuel and oxidizer, as well as improving energy utilization of the synthesis process. Rapidly mixed tubular flame burners are considered in this paper as a promising alternative, combining non-premixed safety combustion with strong turbulent mixing, robust flame stability, and high thermal efficiency. In this paper, the large-scale production of TiO2 nanoparticles in rapidly mixed tubular flame burners is investigated experimentally and numerically. A pilot-scale system is employed to sevaluate the effects of equivalent production rate, tube length and air flow rate on the size, morphology and crystallite phase composition (rutile, anatase, and amorphous fractions) of the TiO2 product. Within the operational window for synthesis of tailor-made TiO2 nanoparticles, the primary particle diameter is able to be tuned from 12.3 nm to 46.9 nm, and the rutile phase content from 8.2 wt.% to 42.9 wt.%, with the remaining fraction comprising anatase and amorphous phases. This broad tunability of particle size, morphology, and crystallinity highlights the strong potential of swirl-stabilized, rapidly mixed tubular flames for scalable flame aerosol synthesis. In addition, a fully coupled LES-bivariate sectional model (LES-BiSe) is used to simulate the spatiotemporally resolved formation and growth of TiO2 nanoparticles in the turbulent flames. The turbulent flame, precursor chemistry, and particle evolution under varying synthesis conditions are comprehensively discussed to reveal the dominant mechanisms governing the formation of targeted nanoparticle properties.
{"title":"Pilot-scale TiO2 nanoparticle synthesis by TiCl4 oxidation in an enclosed flame aerosol reactor","authors":"Song He, Fei Xie, Haibo Zhao","doi":"10.1016/j.combustflame.2026.114844","DOIUrl":"10.1016/j.combustflame.2026.114844","url":null,"abstract":"<div><div>Vapor-fed flame aerosol synthesis is a powerful and versatile technique for the large-scale production of nanomaterials. However, further improvements are still in great demand for enhancing rapidly mixed combustion of non-premixed fuel and oxidizer, as well as improving energy utilization of the synthesis process. Rapidly mixed tubular flame burners are considered in this paper as a promising alternative, combining non-premixed safety combustion with strong turbulent mixing, robust flame stability, and high thermal efficiency. In this paper, the large-scale production of TiO<sub>2</sub> nanoparticles in rapidly mixed tubular flame burners is investigated experimentally and numerically. A pilot-scale system is employed to sevaluate the effects of equivalent production rate, tube length and air flow rate on the size, morphology and crystallite phase composition (rutile, anatase, and amorphous fractions) of the TiO<sub>2</sub> product. Within the operational window for synthesis of tailor-made TiO<sub>2</sub> nanoparticles, the primary particle diameter is able to be tuned from 12.3 nm to 46.9 nm, and the rutile phase content from 8.2 wt.% to 42.9 wt.%, with the remaining fraction comprising anatase and amorphous phases. This broad tunability of particle size, morphology, and crystallinity highlights the strong potential of swirl-stabilized, rapidly mixed tubular flames for scalable flame aerosol synthesis. In addition, a fully coupled LES-bivariate sectional model (LES-BiSe) is used to simulate the spatiotemporally resolved formation and growth of TiO<sub>2</sub> nanoparticles in the turbulent flames. The turbulent flame, precursor chemistry, and particle evolution under varying synthesis conditions are comprehensively discussed to reveal the dominant mechanisms governing the formation of targeted nanoparticle properties.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114844"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185202","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}
<div><div>As part of the FLARE project, long-duration microgravity experiments were conducted on two additional materials—non-charring PMMA and charring NOMEX HT90-40—using the Solid Combustion Experimental Module (SCEM) onboard the ISS/Kibo module. Flammability maps were obtained under opposed-flow velocities, including quiescent conditions, extending previous studies performed with filter paper. For PMMA, both the limiting oxygen concentration (LOC) and the minimum LOC (MLOC) agreed well with predictions from a simplified two-dimensional scaling model, confirming its applicability to thermally thin, non-charring materials. In contrast, NOMEX exhibited robust three-dimensional spherical flames once the two-dimensional thermal balance broke down, even at moderate flow velocities. Under these conditions, the flame radius <em>R<sub>f</sub></em> decreased with decreasing opposed-flow velocity, and extinction occurred when <em>R<sub>f</sub></em> reached a critical value. To quantify this behavior, the preheat-zone length <em>L<sub>g</sub></em> of three-dimensional flames was modeled as a function of <em>R<sub>f</sub></em> and the Reynolds number <em>Re</em>, and incorporated into the thermal balance to derive a limiting oxygen concentration for three-dimensional flames. The resulting expression reproduced the observed relationships among <em>R<sub>f</sub>, V<sub>g</sub></em>, and <em>L<sub>g</sub></em>, and correctly predicted the extinction behavior. Applying the same formulation to filter paper and PMMA further demonstrated that the critical flame radius provides a unified criterion for the transition and extinction of three-dimensional flames across different material classes. These findings demonstrate that both the two-dimensional and three-dimensional flammability limits of charring and non-charring materials can be predicted within a unified experimental–modeling framework, and they provide essential guidance for advancing microgravity fire-safety modeling.</div><div>Novelty and significance statement: The novelty of this work lies in establishing a unified, physics-based framework for predicting flame-spread limits of both charring and non-charring thermally thin materials in microgravity. First, long-duration ISS experiments demonstrated that the limiting oxygen concentration (LOC) and minimum LOC of PMMA are accurately captured by a simplified two-dimensional model, confirming that extinction is governed by the breakdown of two-dimensional thermal balance. A second and central contribution is the quantitative characterization of three-dimensional spherical flames observed in NOMEX beyond the two-dimensional limit. By modeling the preheat-zone length <em>L<sub>g</sub></em> as a function of flame radius <em>R<sub>f</sub></em> and Reynolds number <em>Re</em> and incorporating this into the thermal balance, an explicit LOC criterion for three-dimensional flames was derived. Applying the same formulation to filter paper and PMMA showed that the
{"title":"Flame spread over charring and non-charring materials in microgravity on ISS/Kibo","authors":"Shuhei Takahashi , Yoshinari Kobayashi , Masao Kikuchi , Osamu Fujita","doi":"10.1016/j.combustflame.2026.114803","DOIUrl":"10.1016/j.combustflame.2026.114803","url":null,"abstract":"<div><div>As part of the FLARE project, long-duration microgravity experiments were conducted on two additional materials—non-charring PMMA and charring NOMEX HT90-40—using the Solid Combustion Experimental Module (SCEM) onboard the ISS/Kibo module. Flammability maps were obtained under opposed-flow velocities, including quiescent conditions, extending previous studies performed with filter paper. For PMMA, both the limiting oxygen concentration (LOC) and the minimum LOC (MLOC) agreed well with predictions from a simplified two-dimensional scaling model, confirming its applicability to thermally thin, non-charring materials. In contrast, NOMEX exhibited robust three-dimensional spherical flames once the two-dimensional thermal balance broke down, even at moderate flow velocities. Under these conditions, the flame radius <em>R<sub>f</sub></em> decreased with decreasing opposed-flow velocity, and extinction occurred when <em>R<sub>f</sub></em> reached a critical value. To quantify this behavior, the preheat-zone length <em>L<sub>g</sub></em> of three-dimensional flames was modeled as a function of <em>R<sub>f</sub></em> and the Reynolds number <em>Re</em>, and incorporated into the thermal balance to derive a limiting oxygen concentration for three-dimensional flames. The resulting expression reproduced the observed relationships among <em>R<sub>f</sub>, V<sub>g</sub></em>, and <em>L<sub>g</sub></em>, and correctly predicted the extinction behavior. Applying the same formulation to filter paper and PMMA further demonstrated that the critical flame radius provides a unified criterion for the transition and extinction of three-dimensional flames across different material classes. These findings demonstrate that both the two-dimensional and three-dimensional flammability limits of charring and non-charring materials can be predicted within a unified experimental–modeling framework, and they provide essential guidance for advancing microgravity fire-safety modeling.</div><div>Novelty and significance statement: The novelty of this work lies in establishing a unified, physics-based framework for predicting flame-spread limits of both charring and non-charring thermally thin materials in microgravity. First, long-duration ISS experiments demonstrated that the limiting oxygen concentration (LOC) and minimum LOC of PMMA are accurately captured by a simplified two-dimensional model, confirming that extinction is governed by the breakdown of two-dimensional thermal balance. A second and central contribution is the quantitative characterization of three-dimensional spherical flames observed in NOMEX beyond the two-dimensional limit. By modeling the preheat-zone length <em>L<sub>g</sub></em> as a function of flame radius <em>R<sub>f</sub></em> and Reynolds number <em>Re</em> and incorporating this into the thermal balance, an explicit LOC criterion for three-dimensional flames was derived. Applying the same formulation to filter paper and PMMA showed that the ","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114803"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036403","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}
This study investigates the flame spread behavior of thin wires under simulated lunar (0.166 G) and terrestrial (1 G) gravity conditions using a centrifuge aboard a parabolic flight platform. Experiments were conducted under both uniform gravity and artificial gravity generated by centrifugal acceleration. The effects of gravity on flame spread were examined through flame shape observation, pressure measurement, flow visualization, motion analysis of induced convection, and flammability limit evaluation. Results demonstrated that the flammable range of the specimens expands under artificial gravity compared to uniform gravity. Flow visualization revealed the formation of a swirling convective flow around the axis of rotation, driven by the combined effects of centrifugal and Coriolis forces. This recirculating flow increased chamber gas temperature by reducing the cooling effects of internal structures, resulting in a 4–6 kPa higher pressure rise during flame spread. Motion analysis indicated that convection under artificial gravity exhibits quasi-steady rotational behavior, which suppresses overall convective strength. These findings suggest that simply matching the centrifugal force at the specimen location is insufficient for quantitatively reproducing extinction behavior observed under uniform gravity. To achieve comparable flammability limits, a centrifugal force exceeding 1.5 times the equivalent gravitational acceleration is required under the present setup. The dynamics of swirling recirculating flow play a critical role in determining flame behavior in artificial gravity environments.
{"title":"Investigation of flame spread over a thin wire under simulated lunar and terrestrial gravity using a centrifuge during parabolic flight","authors":"Yusuke Konno , Kenshin Hiraga , Nozomu Hashimoto , Masao Kikuchi , Osamu Fujita","doi":"10.1016/j.combustflame.2026.114800","DOIUrl":"10.1016/j.combustflame.2026.114800","url":null,"abstract":"<div><div>This study investigates the flame spread behavior of thin wires under simulated lunar (0.166 G) and terrestrial (1 G) gravity conditions using a centrifuge aboard a parabolic flight platform. Experiments were conducted under both uniform gravity and artificial gravity generated by centrifugal acceleration. The effects of gravity on flame spread were examined through flame shape observation, pressure measurement, flow visualization, motion analysis of induced convection, and flammability limit evaluation. Results demonstrated that the flammable range of the specimens expands under artificial gravity compared to uniform gravity. Flow visualization revealed the formation of a swirling convective flow around the axis of rotation, driven by the combined effects of centrifugal and Coriolis forces. This recirculating flow increased chamber gas temperature by reducing the cooling effects of internal structures, resulting in a 4–6 kPa higher pressure rise during flame spread. Motion analysis indicated that convection under artificial gravity exhibits quasi-steady rotational behavior, which suppresses overall convective strength. These findings suggest that simply matching the centrifugal force at the specimen location is insufficient for quantitatively reproducing extinction behavior observed under uniform gravity. To achieve comparable flammability limits, a centrifugal force exceeding 1.5 times the equivalent gravitational acceleration is required under the present setup. The dynamics of swirling recirculating flow play a critical role in determining flame behavior in artificial gravity environments.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114800"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184675","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 : 2026-04-01Epub Date: 2026-01-27DOI: 10.1016/j.combustflame.2026.114794
Xudong Song , Yuanyuan Jing , Runmin Wu , Linmin Zhang , Yan Gong , Zhengdong Gu , Juntao Wei , Manoj Kumar Jena , Yonghui Bai , Guangsuo Yu
The study designed and constructed an experimental platform with different nozzle angles and conducted systematic investigations by combining high-resolution UV imaging and high-speed photography. Experiments were performed by adjusting the equivalence ratio and hydrogen addition ratio to obtain key parameters such as flame lift-off height, OH* peak intensity, and core reaction zone area under different nozzle angles. The results indicate that at smaller nozzle angles (e.g., 45°), the flame base’s shear and turbulence are enhanced, which promotes complete mixing of fuel and oxygen, and exhibits higher lift-off height and more stable combustion. In contrast, larger angles (e.g., 75°, 90°) result in asymmetric flame structures, with an expanded core reaction zone but reduced lift-off height and flame stability. Furthermore, a dimensionless prediction model for lift-off height incorporating the average velocity ratio (RV) was proposed, demonstrating good fitting performance with R² > 0.85 for flame behavior across different nozzle angles. This study provides key contributions to nozzle design optimization and enhanced flame stability in low-carbon fuel combustion.
{"title":"Investigation on the effect of nozzle angle on the stability of methane-hydrogen/oxygen inverse diffusion lifted flame","authors":"Xudong Song , Yuanyuan Jing , Runmin Wu , Linmin Zhang , Yan Gong , Zhengdong Gu , Juntao Wei , Manoj Kumar Jena , Yonghui Bai , Guangsuo Yu","doi":"10.1016/j.combustflame.2026.114794","DOIUrl":"10.1016/j.combustflame.2026.114794","url":null,"abstract":"<div><div>The study designed and constructed an experimental platform with different nozzle angles and conducted systematic investigations by combining high-resolution UV imaging and high-speed photography. Experiments were performed by adjusting the equivalence ratio and hydrogen addition ratio to obtain key parameters such as flame lift-off height, OH* peak intensity, and core reaction zone area under different nozzle angles. The results indicate that at smaller nozzle angles (e.g., 45°), the flame base’s shear and turbulence are enhanced, which promotes complete mixing of fuel and oxygen, and exhibits higher lift-off height and more stable combustion. In contrast, larger angles (e.g., 75°, 90°) result in asymmetric flame structures, with an expanded core reaction zone but reduced lift-off height and flame stability. Furthermore, a dimensionless prediction model for lift-off height incorporating the average velocity ratio (R<sub>V</sub>) was proposed, demonstrating good fitting performance with R² > 0.85 for flame behavior across different nozzle angles. This study provides key contributions to nozzle design optimization and enhanced flame stability in low-carbon fuel combustion.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114794"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075094","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 : 2026-04-01Epub Date: 2026-01-28DOI: 10.1016/j.combustflame.2026.114840
Boris Roux , Yves Simon , Sandra Poeuf , Marc Bouchez , Maxime Lechevallier , Pierre-Alexandre Glaude , Baptiste Sirjean , René Fournet
An experimental study of the pyrolysis of cumene was performed at atmospheric pressure, in a jet-stirred reactor (JSR) with 2% fuel diluted in helium, a residence time of 1 s, and for temperatures ranging from 863 to 1023 K. Fifty-four species were identified from light compounds to C20, by gas chromatography coupled with mass spectrometry (GC–MS) and quantified by GC-FID (flame ionization detector) and GC-PDHID (pulsed discharged helium ionization detector). Among these products, several aromatic species (C₉+) were detected for the first time. In addition, a comprehensive kinetic model, including a growth sub-mechanism to bicycle compounds with sizes up to C14, has been developed, based on electronic structure calculations, performed at the QCISD(T)/CBS//B2PLYP-D3/6–311+G(d,p) level of theory. Calculations were used to derive kinetic parameters and thermodynamic data. Comparisons between experiments and simulations showed good agreement for thirty-six species, including the most important products and a marked improvement from previous modeling studies reported in the literature. The allylic H-atom and tertiary carbon atom allows cumene to readily decompose to form styrene, benzene and α-methylstyrene, the main primary aromatic compounds. These species are less reactive than cumene, and our study clearly shows the importance of addition reactions on their side chain or aromatic ring, leading to the formation of bicyclic structures that are key intermediates in the formation of heavier PAHs. In particular, our mechanism models the formation of mono- and bi-aromatic products that had not previously been reported during cumene pyrolysis, such as trimethylbenzene, butenylbenzene, an important precursor of 3-methylindene, as well as diphenylethylene and diphenylstyrene, which are PAH precursors. In addition, a detailed investigation of the potential energy surfaces has clarified the elementary steps involved in the formation pathways of all modeled species, including various isomers, such as methylnaphthalene and methylindene. In particular, the involvement of sigmatropic rearrangements accounts for the formation of 2-methylindene and 2-methylnaphthalene.
{"title":"Cumene pyrolysis: a combined experimental and Ab initio modeling approach","authors":"Boris Roux , Yves Simon , Sandra Poeuf , Marc Bouchez , Maxime Lechevallier , Pierre-Alexandre Glaude , Baptiste Sirjean , René Fournet","doi":"10.1016/j.combustflame.2026.114840","DOIUrl":"10.1016/j.combustflame.2026.114840","url":null,"abstract":"<div><div>An experimental study of the pyrolysis of cumene was performed at atmospheric pressure, in a jet-stirred reactor (JSR) with 2% fuel diluted in helium, a residence time of 1 s, and for temperatures ranging from 863 to 1023 K. Fifty-four species were identified from light compounds to C<sub>20</sub>, by gas chromatography coupled with mass spectrometry (GC–MS) and quantified by GC-FID (flame ionization detector) and GC-PDHID (pulsed discharged helium ionization detector). Among these products, several aromatic species (C₉+) were detected for the first time. In addition, a comprehensive kinetic model, including a growth sub-mechanism to bicycle compounds with sizes up to C<sub>14</sub>, has been developed, based on electronic structure calculations, performed at the QCISD(T)/CBS//B2PLYP-D3/6–311+<em>G</em>(d,p) level of theory. Calculations were used to derive kinetic parameters and thermodynamic data. Comparisons between experiments and simulations showed good agreement for thirty-six species, including the most important products and a marked improvement from previous modeling studies reported in the literature. The allylic H-atom and tertiary carbon atom allows cumene to readily decompose to form styrene, benzene and α-methylstyrene, the main primary aromatic compounds. These species are less reactive than cumene, and our study clearly shows the importance of addition reactions on their side chain or aromatic ring, leading to the formation of bicyclic structures that are key intermediates in the formation of heavier PAHs. In particular, our mechanism models the formation of mono- and bi-aromatic products that had not previously been reported during cumene pyrolysis, such as trimethylbenzene, butenylbenzene, an important precursor of 3-methylindene, as well as diphenylethylene and diphenylstyrene, which are PAH precursors. In addition, a detailed investigation of the potential energy surfaces has clarified the elementary steps involved in the formation pathways of all modeled species, including various isomers, such as methylnaphthalene and methylindene. In particular, the involvement of sigmatropic rearrangements accounts for the formation of 2-methylindene and 2-methylnaphthalene.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114840"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075182","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 : 2026-04-01Epub Date: 2026-02-09DOI: 10.1016/j.combustflame.2026.114858
Huizhen Li , Huahua Xiao
Co-firing with other highly active fuels and partially dissociated ammonia (NH3) are the two attractive ways to enhance the combustion properties of NH3. In view of the ammonia/dimethyl ether/hydrogen (NH3/DME/H2) mixed combustion, it is necessary to explore the influence of different H2 sources in blends on combustion characteristics. This work conducted experiments and simulations to study the differences in flame propagation between NH3/DME/Air mixtures with partially dissociated NH3 and those with H2 addition. The flame morphology and laminar burning velocity (SL) of 80%NH3/20%DME/Air mixtures with various H2 additions (XH2 = 0-0.9) and NH3 cracking ratios (γ = 0-0.9) were measured at equivalence ratios of ϕ = 0.7-1.7 and normal temperature/pressure (Tu = 298 K, Pu = 0.1 MPa) using the spherical constant-volume combustion approach. By comparing the change of instability evaluation parameters with increasing H2 content, it can be inferred that the more wrinkles caused by the increase of H2 concentration are mainly due to the enhancement of hydrodynamic instability caused by the decreasing flame thickness, and the mixtures with H2 addition are more prone to flame instability than those with partially dissociated NH3. The results of the measured and predicted SL show that the partially dissociated NH3 in NH3/DME/Air mixtures can promote combustion to a higher extent than adding H2 directly due to the more H2 produced as γ = XH2, and the degree is more serious with the increase of H2 content. The results of decoupling thermal effect and chemical effect show that SL is mainly dominated by the chemical effect. Compared to the mixtures with H2 addition, the mixtures with partially dissociated NH3 have a stronger promoting effect on chemical effect, while a weaker effect on thermal effect. In addition, the combustion processes of these two kinds of mixtures are similar through sensitivity and reaction pathways analysis.
{"title":"Differences between the effects of NH3 cracking and H2 addition on the flame propagation of NH3/DME/Air mixtures: An experimental and kinetic study","authors":"Huizhen Li , Huahua Xiao","doi":"10.1016/j.combustflame.2026.114858","DOIUrl":"10.1016/j.combustflame.2026.114858","url":null,"abstract":"<div><div>Co-firing with other highly active fuels and partially dissociated ammonia (NH<sub>3</sub>) are the two attractive ways to enhance the combustion properties of NH<sub>3</sub>. In view of the ammonia/dimethyl ether/hydrogen (NH<sub>3</sub>/DME/H<sub>2</sub>) mixed combustion, it is necessary to explore the influence of different H<sub>2</sub> sources in blends on combustion characteristics. This work conducted experiments and simulations to study the differences in flame propagation between NH<sub>3</sub>/DME/Air mixtures with partially dissociated NH<sub>3</sub> and those with H<sub>2</sub> addition. The flame morphology and laminar burning velocity (S<sub>L</sub>) of 80%NH<sub>3</sub>/20%DME/Air mixtures with various H<sub>2</sub> additions (X<sub>H2</sub> = 0-0.9) and NH<sub>3</sub> cracking ratios (γ = 0-0.9) were measured at equivalence ratios of ϕ = 0.7-1.7 and normal temperature/pressure (T<sub>u</sub> = 298 K, P<sub>u</sub> = 0.1 MPa) using the spherical constant-volume combustion approach. By comparing the change of instability evaluation parameters with increasing H<sub>2</sub> content, it can be inferred that the more wrinkles caused by the increase of H<sub>2</sub> concentration are mainly due to the enhancement of hydrodynamic instability caused by the decreasing flame thickness, and the mixtures with H<sub>2</sub> addition are more prone to flame instability than those with partially dissociated NH<sub>3</sub>. The results of the measured and predicted S<sub>L</sub> show that the partially dissociated NH<sub>3</sub> in NH<sub>3</sub>/DME/Air mixtures can promote combustion to a higher extent than adding H<sub>2</sub> directly due to the more H<sub>2</sub> produced as γ = X<sub>H2</sub>, and the degree is more serious with the increase of H<sub>2</sub> content. The results of decoupling thermal effect and chemical effect show that S<sub>L</sub> is mainly dominated by the chemical effect. Compared to the mixtures with H<sub>2</sub> addition, the mixtures with partially dissociated NH<sub>3</sub> have a stronger promoting effect on chemical effect, while a weaker effect on thermal effect. In addition, the combustion processes of these two kinds of mixtures are similar through sensitivity and reaction pathways analysis.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114858"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185201","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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