Combustion and Flame最新文献

{"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 ,&nbsp;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 (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 (S_L) of 80%NH₃/20%DME/Air mixtures with various H₂ additions (X_H2 = 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 (T_u = 298 K, P_u = 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 S_L 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 = X_H2, and the degree is more serious with the increase of H₂ content. The results of decoupling thermal effect and chemical effect show that S_L 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.</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}

{"title":"Experimental study of the effect of electrode geometry on the ignition and flame development of NH3/air mixtures in nanosecond plasma discharges","authors":"Jie Tian ,&nbsp;Huichao Jing ,&nbsp;Yong Xiong ,&nbsp;Lu Wang ,&nbsp;Yongqi Wang ,&nbsp;Qingwu Zhao ,&nbsp;Yong Cheng","doi":"10.1016/j.combustflame.2026.114809","DOIUrl":"10.1016/j.combustflame.2026.114809","url":null,"abstract":"<div><div>This study experimentally investigates the discharge characteristics, ignition performance, and flame development law of NH₃/air mixtures with respect to different electrode geometries, namely a pin-pin electrode (Electrode A), a conventional nanosecond surface dielectric barrier discharge (nSDBD) coaxial electrode (Electrode B), and a self-designed radiant multi-zone regulated nSDBD electrode (Electrode C). The effects of work state parameters, including initial pressure (1-3 bar), excess air coefficient λ (1.0-1.4), and initial temperature (333-393 K), were also analysed. Under the reference conditions (initial pressure of 2 bar, initial temperature of 363 K, and λ = 1.0), the results show that: Electrode A achieves the shortest flame development time (15.0 ms) relying on a single-point high energy density, but the flame morphology is irregular; Electrode B exhibits the worst combustion performance due to random discharge and dispersed energy, which easily leads to the extinction of flame kernels; Electrode C, through six symmetric conductive areas, realizes the synchronous fusion of multiple flame kernels and demonstrates the optimal stability and adaptability. Under a wide range of operating conditions, Electrode C shows excellent robustness: it still maintains stable multiple flame kernels at 3 bar (while the number of flame kernels of Electrode B decreases by more than 50%), and it is time to reach the standard heat release is 11% shorter than that of Electrode B; at λ = 1.4, the number of flame kernels of Electrode C is 2–3 times that of Electrode B; when the temperature changes, the fluctuation in the time for the combustion pressure peak to reach its maximum value is less than 5% (compared to 26% for Electrode B). This study reveals the mechanism by which electrode geometry influences plasma and ammonia ignition, confirms the advantages of Electrode C, and provides theoretical and technical support for optimizing plasma ignition systems for ammonia fuel.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114809"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on the low-pressure hypergolic performance of catalytic and reactive fuels","authors":"Geng Li,&nbsp;Peng Chen,&nbsp;Zhan Zhong,&nbsp;Gangqiang Wu,&nbsp;Zhi Li,&nbsp;Peng Wang,&nbsp;Weidong Huang,&nbsp;Wansheng Nie","doi":"10.1016/j.combustflame.2026.114812","DOIUrl":"10.1016/j.combustflame.2026.114812","url":null,"abstract":"<div><div>Hypergolic propellants are widely used in various spacecraft propulsion systems, and hydrogen peroxide has received increasing attention as an oxidizing agent for nontoxic green propellants. In this work, the ignition delay time and low-pressure hypergolic limit are measured during a jet collision test for a combination of catalytic fuel (N,N,N',N'-tetramethyl ethylenediamine (TMEDA)/N,N-dimethylethanolamine (DMEA)+ cupric acetate) and reactive fuel (triethylene glycol dimethyl ether+ sodium borohydride) with hydrogen peroxide under different nitrogen gas pressures. The test results reveal that at low pressure, the ignition delay of catalytic fuel increases exponentially with decreasing ambient pressure, and the ignition limit decreases with increasing catalyst content. The ignition delay time of the reactive fuel is shorter than that of the catalytic fuel, and although the evaporation phenomenon after mixing is more obvious when the ambient pressure is reduced, the amount of evaporation before ignition is small, the evaporation process has a minimal effect on the ignition process, and the ignition delay time of the reactive fuel remains almost unchanged. Moreover, at 5 kPa, the ignition delay increases due to the change in the hydrogen peroxide jet state. Calculations via the CEA method indicate that the specific impulse and density-specific impulse of the reactive fuel are essentially identical to those of the catalytic fuel and differ only marginally from conventional hypergolic fuels. These results indicate that environmental pressure exerts differing effects on the ignition delay of various fuel types, rendering reactive fuel more suitable for engine start-up under fluctuating environmental pressure conditions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114812"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Combustion Instability in Multi-Nozzle Can Combustor via MIMO Thermoacoustic Model with Combined Fuel Staging","authors":"Junwoo Jung ,&nbsp;Vo Quang Sang ,&nbsp;Jihwan Seong ,&nbsp;Chae Hoon Sohn ,&nbsp;Min Kuk Kim ,&nbsp;Jeongjae Hwang ,&nbsp;Won June Lee ,&nbsp;Daesik Kim","doi":"10.1016/j.combustflame.2026.114842","DOIUrl":"10.1016/j.combustflame.2026.114842","url":null,"abstract":"<div><div>Hydrogen co-firing and lean premixed combustion technologies in modern gas turbines have significantly increased concerns regarding combustion instability. Although fuel staging has emerged as an effective control method, existing studies have focused on individual staging approaches, limiting our understanding of the combined staging effects. In this study, a comprehensive thermoacoustic stability map was developed by simultaneously applying outer nozzle fuel staging and pilot injection under 30% hydrogen co-firing conditions, providing a predictive framework for multiparameter instability control. An integrated methodology combining experiments, computational fluid dynamics (CFD), and thermoacoustic modeling was employed to investigate the interaction effects between the pilot injection and outer nozzle fuel staging. Experimental investigations revealed that the combined effects of pilot injection and outer nozzle fuel staging on dynamic pressure amplitudes exhibited complex interdependencies that varied with operating conditions. CFD analysis identified the underlying physical mechanisms and showed that different staging parameters modify the flame structure and time delay characteristics of the outer nozzles in distinct ways. A multi-input multi-output (MIMO) thermoacoustic model was developed to construct a stability map that incorporates the time-delay variations of outer nozzles. The stability map successfully captured the effects of pilot injection and outer nozzle fuel staging on the combustion instability characteristics. This integrated framework provides a practical design tool for optimizing fuel staging strategies in hydrogen-compatible gas turbines.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114842"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is the NH3 + N2O = H3NO + N2 reaction important in ammonia oxidation by nitrous oxide or oxygen?","authors":"Xiaoyang Lei ,&nbsp;Xiao Liu ,&nbsp;Bin Yang ,&nbsp;Shuiqing Li","doi":"10.1016/j.combustflame.2026.114824","DOIUrl":"10.1016/j.combustflame.2026.114824","url":null,"abstract":"<div><div>Nitrous oxide (N₂O) is an important intermediate/pollutant in combustion, particularly in the case of ammonia. Meanwhile, it can also be used as oxidizer or additive in the oxidation of fuels or propellants. Many studies have been performed for ammonia oxidation by N₂O or O₂. Whereas, the answers for the two basic questions “what are the main consumption pathways of N₂O in ammonia oxidation by N₂O or O₂?” and “why adding N₂O can improve the reactivity of ammonia for combustion?” are still unknown. In this work, the direct reactions between NH₃ and N₂O are investigated by quantum-chemical and kinetic calculations. The computations indicate that the dominant pathway of the NH₃ + N₂O reaction is to directly produce a zwitterionic intermediate, H₃NO, and N₂ molecule via the O-attack mechanism. The H₃NO intermediate is a metastable tautomer of hydroxylamine (NH₂OH), and its detection and characterization in the gas phase is still a challenge for experimentalists. To evaluate the importance of the NH₃ + N₂O reaction in ammonia oxidation by N₂O or O₂, twelve combustion models of ammonia in literatures are modified by the computed reaction parameters. The simulations show that the NH₃ + N₂O = H₃NO + N₂ reaction plays an important role in the consumption of N₂O during ammonia oxidation by N₂O and O₂. Therefore, this reaction should be much more considered in the development of ammonia combustion model.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114824"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of hydrogen enrichment on the autoignition and lift-off behavior of ammonia jet flames in hot coflows","authors":"Daeyoung Jun ,&nbsp;Seo Hee Cho ,&nbsp;V. Mahendra Reddy ,&nbsp;Bok Jik Lee","doi":"10.1016/j.combustflame.2026.114820","DOIUrl":"10.1016/j.combustflame.2026.114820","url":null,"abstract":"<div><div>Ammonia is a promising carbon-free fuel, but its low reactivity presents a limitation. To mitigate this, hydrogen enrichment can be considered. This experimental study investigates the combustion characteristics and lift-off behaviors of autoignited ammonia–hydrogen flames. A jet in a hot oxidant coflow burner is used to examine the impact of hydrogen enrichment on ammonia jets. The flames exhibit distinct regimes, including attached, lifted, decoupled lifted flames, and blowout, influenced by hydrogen content, jet Reynolds number, and oxygen concentration. As expected, increasing hydrogen content and oxygen concentration stabilized the flame, promoting attachment. Distinctly decoupled lifted flames were observed, characterized by the separation of laminar and turbulent flame branches at the break-up point due to local extinction induced by high strain from developing eddies. Furthermore, flame pocket evolution in lifted flames was analyzed using high-speed imaging, revealing that flame pockets either grew to form new flame bases or were extinguished. During extinction, local turbulent structures cause larger flame pockets to fragment into smaller ones, which are subsequently extinguished rapidly. Regarding the spatial distribution of flame pockets, both decreasing hydrogen content and increasing jet velocity led to a downstream axial shift of the flame pocket locations. In terms of the number of flame pockets, the hydrogen content exhibited a more pronounced effect than the jet velocity. To find the flame stabilization mechanism, several lift-off height models were considered. The large-scale mixing model with autoignition time provided the best prediction, suggesting that flame stabilization is primarily governed by the balance between mixing and autoignition kinetics rather than flame propagation. This was further verified by the blowout correlation.</div><div><strong>Novelty and significance</strong>: The novelty of this study lies in its investigation of ammonia–hydrogen jet flames in hot coflow environments, focusing on the stabilization mechanism of binary fuels with autoignition. Hydrogen enrichment, widely used to compensate for ammonia’s low reactivity, introduces additional complexity due to the large disparity in transport properties, particularly diffusivity. This study examines flame behavior, the transient evolution of flame pockets, and evaluates the applicability of various lift-off correlations. A large-scale mixing model with the autoignition time of a uniform fuel mixture remains effective in predicting lift-off height, despite the pronounced differential diffusion between hydrogen and ammonia. The findings of the present study could provide valuable insights for applications involving ammonia–hydrogen jet combustion.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114820"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flame Chemistry Workshop: a perspective on challenges and strategic actions in combustion experiments and chemical kinetics modeling","authors":"B. Rotavera ,&nbsp;L. Cai ,&nbsp;F. Zhang ,&nbsp;A. Comandini ,&nbsp;N. Hansen ,&nbsp;S.J. Klippenstein ,&nbsp;B. Yang ,&nbsp;M. Pelucchi","doi":"10.1016/j.combustflame.2026.114863","DOIUrl":"10.1016/j.combustflame.2026.114863","url":null,"abstract":"<div><div>Continued progress in the development of predictive models for combustion chemistry—including ignition and flame behavior, species evolution, and combustion system performance—relies on overcoming enduring and emerging challenges in experimental measurements, theoretical formulations, and chemical kinetics mechanism construction. As combustion science continues to coincide with advances in sustainable fuels development, plasma technologies, and automated modeling capabilities, the need for coordinated, community-driven strategies is essential. The Flame Chemistry Workshop (FCWS), held biennially before the International Symposium on Combustion, serves as a dedicated platform to identify, consolidate, and address these challenges in a structured and collaborative manner.</div><div>This perspective arises from discussions at the 7th FCWS in Milan, Italy (2024), and presents a collective view of the critical barriers currently limiting progress. Across the five technical domains discussed during the 7th FCWS – sustainable fuels combustion, advanced diagnostics for combustion measurements, experiments and modeling in plasma combustion, artificial intelligence and automated methods for theory and mechanisms generation, and chemical kinetic models—a series of persistent and emerging scientific challenges were identified, highlighting the need for deeper integration between three areas: theory, experiments, and modeling. The present article concisely describes present challenges that were identified in each of the technical domains in an effort to streamline and coordinate solutions to accelerate progress in combustion science.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114863"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146184844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-dependent-bases with local CUR decomposition method for accelerating turbulent combustion simulations","authors":"Jae Jung Kim ,&nbsp;Cristian E. Lacey ,&nbsp;Jun Hyung Lee ,&nbsp;Ki Sung Jung ,&nbsp;Jacqueline H. Chen ,&nbsp;Chun Sang Yoo","doi":"10.1016/j.combustflame.2026.114848","DOIUrl":"10.1016/j.combustflame.2026.114848","url":null,"abstract":"<div><div>This study presents a novel reduced-order modeling framework, Time-Dependent Bases with Local CUR decomposition (TDB-L-CUR), designed to efficiently and accurately approximate the species transport equations in reacting flow simulations. The method extends the existing TDB-CUR approach for chemically reacting flows (Jung et al. <em>Comput. Methods Appl. Mech. Engrg. 437</em> (2025) 117758), which leverages matrix decomposition techniques to form a global-in-space, time-dependent low-dimensional manifold. While TDB-CUR performs well in homogeneous systems, it may be less well-suited to spatially heterogeneous systems such as turbulent flames, where higher-rank approximations are typically required. The proposed TDB-L-CUR framework introduces two methodological extensions to the baseline approach. First, it applies unsupervised clustering to partition the physical domain into distinct regions, enabling spatially localized manifold construction, thereby reducing the rank required for the reduced-order representation. Second, it incorporates a computational singular perturbation (CSP)-based scheme for identifying and penalizing fast species, allowing for spatio-temporally adaptive mitigation of chemical stiffness. The proposed framework is validated on a hierarchy of test cases, including a one-dimensional premixed flame, a two-dimensional nonpremixed ignition case with vortex interaction, and a three-dimensional turbulent premixed flame. TDB-L-CUR significantly improves accuracy over TDB-CUR while further reducing computational cost. The fully <em>on-the-fly</em> formulation of TDB-L-CUR (i.e., requiring no offline training or prior knowledge) makes it a robust and scalable tool for reduced-order modeling of reactive flows.</div><div><strong>Novelty and significance statement</strong></div><div>The novelty of this work lies in two aspects. First, it establishes spatially localized manifolds that adapt to heterogeneous flow fields, thereby overcoming the accuracy loss and high rank demands that limit conventional global manifold approaches. Second, it provides automated, <em>on-the-fly</em> mitigation of stiffness by performing eigenvalue decomposition to evaluate chemical time scales, eliminating the need for offline training or prior knowledge. Taken together, these advances yield a reduced-order framework that is both accurate and computationally efficient, marking a significant step for reactive flow simulations.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114848"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Markstein number estimation using complete instability of downward propagating planar flames in acoustic field","authors":"Arvind Kumar Ahirwar,&nbsp;Ajit Kumar Dubey","doi":"10.1016/j.combustflame.2026.114805","DOIUrl":"10.1016/j.combustflame.2026.114805","url":null,"abstract":"<div><div>Markstein number (Ma) is an important parameter for premixed flames influencing flame speed and instabilities. This work presents a novel approach for estimating Ma using acoustic parametric instability of flames travelling downward in an open-closed tube. At a constant equivalence ratio, laminar burning velocity (S_L) can be controlled by varying diluent fraction. In such an experiment, at sufficiently high S_L, two types of thermo-acoustic instability are observed: primary instability (where the initial cellular flame transitions to a vibrating planar flame) and secondary instability (where the vibrating planar flame transitions to a vibrating turbulent flame due to parametric instability of the flame front). Upon further raising S_L, to \"critical S_L\", \"complete instability\" of flat flames is seen, indicating that the flat flame cannot be stabilized and the initial cellular flame transitions directly to parametric instability. An analytical model is used for calculating stability of planar flames in acoustic field. The width of stability region of planar flames becomes zero at the critical S_L. This condition is utilized to indirectly obtain Ma for a known critical S_L for methane, ethylene and propane flames diluted with N₂ and CO₂. The Ma estimated from this method are in very good agreement with Ma from literature obtained using growth rates of hydrodynamic instability. Previous attempts to find Ma using acoustic instability have used wavenumber and acoustic amplitude at the onset of parametric instability. These quantities have higher measurement uncertainty. The present method only needs knowledge of mixture composition at critical S_L and thus the error bars are negligible. The method is also extended to mixtures other than the critical S_L mixture. Acoustic instability is influenced by both flow strain and flame curvature, so the estimated Ma contains both effects unlike the counterflow flame (influenced by flow strain) and spherical flames (influenced by curvature).</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114805"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Burning velocity and burn time via particle image velocimetry and modeling for aluminum dust flames","authors":"Vidhan S. Malik ,&nbsp;Christopher J. Pfützner ,&nbsp;Brian T. Bojko ,&nbsp;Vadim N. Gamezo ,&nbsp;Michael J. Soo ,&nbsp;Brian T. Fisher","doi":"10.1016/j.combustflame.2026.114795","DOIUrl":"10.1016/j.combustflame.2026.114795","url":null,"abstract":"<div><div>Metal fuels are theoretically predicted to outperform conventional fuels such as methane and fossil fuels due to their higher energy density content. This paper seeks to quantify combustion properties of aluminum dust such as particle burning velocity, particle burn length, and particle burn time. The experimental work consists of stabilizing an aluminum-air flame in a counter-flow configuration to provide quasi-1D flame measurements. Particle Image Velocimetry (PIV) is used to extract time and length scales of interest. The results show that the gaseous flame speed increases with particle concentration from 0.2 m/s at 300 g/m³ to 0.5 m/s at 700 g/m³ while the particle burn time decreases from ∼4 ms to ∼2 ms and the particle burn length remains almost constant at ∼2–2.5 mm. The experimental results are analyzed using a 1D theoretical model describing particle ignition and combustion stability. A second model analyzes particle-particle interaction relative to powder concentration to reveal that a certain level of particle proximity is required for sustained flames, defined by the overlap of air spheres that surround particles. The 1D modeling results are further developed to incorporate stochastic diameters and spatial positioning in a 3D model where results reflect a non-zero probability of competition for oxygen at all concentration values signifying the importance of intermediate radicals such as AlO and radiation heat transfer.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"286 ","pages":"Article 114795"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036407","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}