Combustion and Flame最新文献

{"title":"Robust 3D tracking of dynamic reacting particles based on holographic spatio-temporal similarity","authors":"Jianqing Huang ,&nbsp;Weiwei Cai ,&nbsp;Zhongshan Li ,&nbsp;Yue Huang","doi":"10.1016/j.combustflame.2026.114899","DOIUrl":"10.1016/j.combustflame.2026.114899","url":null,"abstract":"<div><div>Accurate three-dimensional (3D) tracking of dynamic particles in highly scattering, reacting environments like metal combustion remains challenging for conventional particle tracking velocimetry (PTV). While digital holography enables volumetric imaging, traditional holographic PTV suffers from significant depth positioning errors and velocity fluctuations due to inefficient frame-by-frame processing neglecting inherent space–time continuity. This study presents a novel robust 3D tracking approach that strategically leverages spatio-temporal similarity within sequential holograms to enhance particle matching and localization precision. The core innovation integrates mutual information maximization into the particle pairing and localization process. Calibration using precision-translated particles demonstrated that the proposed method achieved superior depth accuracy (<span><math><mrow><mi>Δ</mi><mi>z</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>25</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>29</mn><mspace></mspace><mstyle><mi>m</mi><mi>m</mi></mstyle></mrow></math></span>) and stability compared to gradient variance and correlation coefficient-based methods. Validation experiments involved reacting iron particles in a jet flame and controlled particle–wall collisions with an inclined plate. This robust, similarity-driven PTV method significantly advances the capability to resolve complex 3D particle trajectories, velocities, and morphology evolution in challenging reactive flows, with promising potential for applications like multiphase flows and confined powder combustion diagnostics.</div><div><strong>Novelty and significance statement</strong> This work presents a novel robust 3D particle tracking algorithm that fundamentally advances digital holography diagnostics for reactive particulate flows. By synergistically integrating Mutual Information-based spatio-temporal similarity, the method enables robust tracking of individual iron particles undergoing ignition, combustion, and wall collisions under extreme conditions—addressing critical challenges in capturing rapid morphological transformations and complex interactions. The capability to resolve continuous 3D trajectories, velocity fields, and size evolution of burning metal particles represents a significant breakthrough, providing unprecedented insights into particle-scale combustion phenomena. This methodology opens new avenues for understanding metal-fuel combustion dynamics and optimizing advanced energy systems, with broad implications for combustion science, multiphase flow diagnostics, and metal-fuel technology development.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114899"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387006","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":"A combined experimental and comprehensive kinetic modeling study of laminar burning velocities for C0–C1 multi-component fuel blends","authors":"Wenchao Zhu ,&nbsp;Taipeng Mao ,&nbsp;Zechuan Cui ,&nbsp;Xinyang Tian ,&nbsp;Jiabei Cao ,&nbsp;Jiangping Tian ,&nbsp;Xiangyu Meng ,&nbsp;Mingshu Bi","doi":"10.1016/j.combustflame.2026.114881","DOIUrl":"10.1016/j.combustflame.2026.114881","url":null,"abstract":"<div><div>The proposal of carbon neutrality targets has accelerated the deployment of C₀–C₁ low- and zero-carbon fuels such as ammonia (NH₃), hydrogen (H₂), methane (CH₄), and methanol (CH₃OH) in energy conversion and power systems. Multi-component fuel blending is widely employed to tailor reactivity and improve emission performance. In this work, laminar burning velocities (LBVs) of NH₃/H₂/air, NH₃/H₂/CH₄/air, and NH₃/H₂/CH₃OH/air blends were measured in a constant-volume combustion chamber at 473 K and 2–8 atm. Based on a previously developed NH₃/CH₄/H₂/CO kinetic mechanism, three key C<img>N cross reactions were incorporated and the rate constants of fifteen C<img>H and H<img>N reactions were updated. This yielded a comprehensive C₀–C₁ kinetic mechanism that comprises 53 species and 354 reactions and accurately reproduces the measured LBVs. To further assess broader applicability, this mechanism was evaluated against C₀–C₁ single and multi-component fuel datasets, including 2035 LBV data points (298–750 K, 1–15 atm, equivalence ratios <em>ϕ</em> = 0.4–5.0), 1618 ignition delay time data points (817–2517 K, 1–50 atm, <em>ϕ</em> = 0.1–2.0), and 6172 species data points measured in jet-stirred reactors (500–1400 K, 1–100 atm, <em>ϕ</em> = 0.1–4.35). Five performance metrics with normalized weights were applied for quantitative evaluation. The results indicated that this mechanism significantly improves overall predictive accuracy relative to previous mechanisms and also shows the closest agreement with experimental data among six recently published representative mechanisms.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114881"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386588","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":"Development and transition process of jet ignition and jet flame ignition in hot turbulent jets by methane active prechamber system","authors":"Wenze Wei ,&nbsp;Run Chen ,&nbsp;Tie Li ,&nbsp;Shuai Huang ,&nbsp;Shiyan Li ,&nbsp;Xinyi Zhou ,&nbsp;Ping Yi ,&nbsp;Qiang Wei","doi":"10.1016/j.combustflame.2026.114923","DOIUrl":"10.1016/j.combustflame.2026.114923","url":null,"abstract":"<div><div>Prechamber structure has significant influence on the jet ignition phenomenon, thereby directly affecting the overall performance and efficiency of natural gas engines. However, the correlation between the prechamber structural features and ignition phenomenon has not yet been clearly elucidated. This work employs a combined experimental and computational approach in a constant volume combustion chamber (CVCC) with single-hole prechamber system to investigate the ignition phenomena and transition process of jet ignition and jet flame ignition. The investigation reveals the prechamber structural control mechanisms governing the ignition phenomenon in lean methane/air ambience, where both the orifice diameter and prechamber volume were varied. The results show that the smaller hole diameter produces a turbulent jet with lower temperature and active radical concentration, promoting a transition from flame to jet ignition and consequently delaying combustion. However, the volume has less effect on the ignition phenomenon. Moreover, the investigation of both ignition phenomena reveals that the initial flame formation consistently occurs in the upstream region of the jet, with subsequent propagation toward the downstream region driven by the jet development. Finally, the turbulent jet ignition coefficient (k) is proposed to characterize the transition of the jet ignition to jet flame ignition. The k represents the ratio of the characteristic reaction time t to the ignition delay τ_T, which is related to initial jet velocity, ambient temperature of main chamber and adiabatic flame temperature of prechamber mixture. In the initial stage of the jet, the k increases faster as the prechamber hole diameter increases, in favour of forming the jet flame ignition. This work provides guidance for the design of prechamber structure, which contributes to the development of more efficient and reliable prechamber engines.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114923"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386925","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":"Effect of metal-carbonitride layered composites with different Ni/Fe molar ratios on the thermal decomposition and combustion performance of energetic components","authors":"Tengyue Song ,&nbsp;Yuhuai Shi ,&nbsp;Shuhan Guo ,&nbsp;Ying Kang ,&nbsp;Peijia Li ,&nbsp;Yuhao Wu ,&nbsp;Xiong Cao","doi":"10.1016/j.combustflame.2026.114928","DOIUrl":"10.1016/j.combustflame.2026.114928","url":null,"abstract":"<div><div>The development of highly efficient catalysts for regulating thermal decomposition and combustion behavior of energetic components is of great significance. This study successfully designed, synthesized and characterized a series of nickel-iron layered double oxide doped graphitic carbon nitride (NFL@CN-X, <em>X</em> = 1, 3, 5) composite combustion catalysts with varying Ni/Fe molar ratios through electrostatic self-assembly followed by thermal treatment. These catalysts exhibit well-developed porous structures and highly active metal centers. The effects of these catalysts on the thermal decomposition behavior of Ammonium perchlorate (AP), Cyclotrimethylene trinitramine (RDX), Cyclotetramethylene tetranitramine (HMX) and Hexanitrohexaazaisowurtzitane (CL-20) were systematically investigated using differential scanning calorimetry (DSC) and thermogravimetric (TG) analyses, and relevant kinetic and thermodynamic parameters were calculated. In addition, the optimal catalyst was employed for ignition experiments, and high-speed camera technology was employed to evaluate their impact on the combustion performance of various energetic composite systems. Furthermore, a potential catalytic mechanism was proposed using HMX as a representative energetic compound, based on thermogravimetric-mass spectrometry (TG-MS) analysis. The DSC and TG results revealed that the incorporation of NFL@CN-X (<em>X</em> = 1, 3, 5) significantly lowered the peak decomposition temperatures (T_p) of AP, RDX, HMX and CL-20 by 73.6∼81.0 °C, 1.3∼2.4 °C, 1.1∼1.5 °C, and 5.1∼7.7 °C, respectively. Correspondingly, the apparent activation energies (E_a) of the energetic composite systems markedly reduced by 113.41∼140.86 kJ·mol⁻¹, 3.44∼29.85 kJ·mol⁻¹, 32.73∼134.58 kJ·mol⁻¹, and 49.77∼66.74 kJ·mol⁻¹ compared with those of the raw samples, respectively. Among these, NFL@CN-5 exhibited the most pronounced catalytic thermal decomposition effect and also significantly enhanced combustion characteristics and energy release efficiency of energetic composite systems. Ignition experiments further demonstrate that energetic systems incorporating NFL@CN-5 exhibit increased flame heights, prolonged combustion durations, and more complete combustion behavior. The NFL@CN series catalysts show great potential as superior alternatives to conventional combustion catalysts.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114928"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387014","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 and numerical investigation of ammonia addition on combustion characteristics and NO formation effects in ammonia/coal co-firing flames","authors":"Yang Liu ,&nbsp;Yan Gong ,&nbsp;Qinghua Guo ,&nbsp;Junhan Liu ,&nbsp;Guangsuo Yu","doi":"10.1016/j.combustflame.2026.114880","DOIUrl":"10.1016/j.combustflame.2026.114880","url":null,"abstract":"<div><div>Ammonia, as a carbon-free fuel, offers a promising pathway for achieving emission reduction through co-combustion with pulverized coal. However, the effect of ammonia addition on coal combustion and the intrinsic mechanisms requires further investigation. In this study, an optical diagnostic platform comprising a two-stage flat flame burner, high-speed imaging system and fiber-optic spectroscopy was employed to investigate the combustion characteristics of NH₃/coal flames at low ammonia blending ratios. CH^⁎ chemiluminescence was utilized to characterize the flame structure and the ignition process. In addition, numerical simulations integrating global mechanisms for coal and ammonia pyrolysis/combustion were conducted to analyze flue gas composition and NO generation. The results indicated that flame height and fuel-rich zone increased significantly with ammonia blending ratios. Coal ignition delay time and the time to the peak intensity exhibit nearly linear growth. Total CO and CO₂ emissions decreased gradually with increasing ammonia concentration, while local CO peak mole fraction increased. It was attributed to the suppression of the critical CO oxidation pathway (CO + OH→CO₂ + H) due to O₂ and OH radical consumption by ammonia. As ammonia blending ratio rises, NO mole concentration increased substantially and coal-N contributed significantly less to NO formation than NH₃-N. The distribution of the NO core zone was governed by the oxidation reaction R10(NH₃ + O₂→NO + H₂O + 0.5H₂) and the reduction reaction R11(NH₃ + NO→N₂ + H₂O + 0.5H₂).</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114880"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386589","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":"Mechanistic tracking of N-species from acrylonitrile (AN) oxidation: Comparison of experimental results and ReaxFF molecular pathways","authors":"Su Zhang,&nbsp;Fuheng Xia,&nbsp;Bingxin Fang,&nbsp;Guan Wang,&nbsp;Yixiang Shu,&nbsp;Bin Liu,&nbsp;Zhaochen Shi,&nbsp;Yili Zhang,&nbsp;Renhui Ruan,&nbsp;Xuebin Wang","doi":"10.1016/j.combustflame.2026.114926","DOIUrl":"10.1016/j.combustflame.2026.114926","url":null,"abstract":"<div><div>The oxidation of Acrylonitrile (AN) was investigated both experimentally and numerically. The effects of temperature (T=773-1273 K), equivalence ratio (φ=0.5, 0.7, 0.9 and 1.2) and residence time (τ=1, 2, 3, 5, 7 s) on AN oxidation were studied in a jet stirred reactor (JSR). The main nitrogen-containing products and intermediates were analyzed in detail using ReaxFF molecular dynamics simulations. These results were compared with experimental data to confirm the accuracy of the model and the nitrogen transfer mechanisms in AN oxidation. The results show that the main nitrogen-containing products of AN oxidation were HCN, NO, N₂O and NH₃. Under fuel-rich conditions (φ = 2.0), HCN formation peaked at approximately 220 ppm at 973 K, while under oxygen-rich conditions (φ = 0.5), NO emissions reached a maximum of ∼120 ppm at 1073 K. When oxygen is sufficient, AN-N (nitrogen atom in acrylonitrile) is rapidly oxidized to the key intermediates HNCO and NCO, which further oxidize to produce NO, NO₂ and N₂O. When oxygen is insufficient, AN-N primarily follows the reduction pathway, producing large amounts of HCN and CN intermediates. This reduces the conversion rate of HNCO to NCO by 50 % compared to oxygen-rich conditions and promotes the formation of NH₃ and N₂.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114926"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386645","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 global equivalence ratio and inlet turbulence intensity on preferential transport in turbulent bluff-body-stabilized premixed ammonia/hydrogen/nitrogen flame","authors":"Min Zhang ,&nbsp;Qiuli Chen ,&nbsp;Yuqiang Li ,&nbsp;Robert S. Barlow ,&nbsp;Zhi X. Chen","doi":"10.1016/j.combustflame.2026.114889","DOIUrl":"10.1016/j.combustflame.2026.114889","url":null,"abstract":"<div><div>Preferential diffusion, known for its important effects on local flame structure and global flame characteristics, has been widely investigated in premixed flames. Recent studies have shown that the preferential transport effect can be amplified by the recirculation zone in bluff-body-stabilized methane flames, while the understanding of this effect still remains limited in ammonia/hydrogen/nitrogen (NH₃/H₂/N₂) flames. This study numerically investigates the preferential transport in turbulent bluff-body-stabilized premixed NH₃/H₂/N₂ flames, focusing on varying global equivalence ratio and inlet turbulence intensity. In all simulation cases, the local equivalence ratio in the recirculation zone increases significantly. This observed increase is attributed to an enhanced preferential transport effect. Preferential diffusion of H₂ ahead of other reactants creates a local depletion within the preheat zone. This H₂-depleted fluid is subsequently advected past the recirculation zone, leaving it enriched beyond the initial reactant stream. As nitrogen monoxide (NO) formation is highly sensitive to the local equivalence ratio, the increase in local equivalence ratio suppresses NO production. As the global equivalence ratio increases, the preferential transport effect within the flame front exhibits a non-monotonic trend that is related to changes in the flame speed. The inlet turbulence intensity slightly alters the preferential transport effect within the recirculation zone. Although flame stretch becomes more influential as the inlet turbulence intensity increases, the rise in local equivalence ratio within the recirculation zone is still dominated by the preferential transport effect. Additionally, the inlet turbulence intensity primarily affects the local equivalence ratio in the flame front through increased wrinkling, enhancing turbulent mixing and thickening the mean flame front.</div><div><strong>Novelty and Significance Statement</strong></div><div>The novelty of this work lies in utilizing flame-resolved simulations to elucidate how the recirculation zone amplifies preferential transport in turbulent bluff-body-stabilized premixed ammonia/hydrogen/nitrogen flames, an area that remains largely unexplored compared with methane-based systems. This study identifies the fundamental mechanism by which variations in the global equivalence ratio and inlet turbulence intensity modify the flow and flame structures in the recirculation zone and consequently alter the strength of preferential transport. Such details could not be captured by previous large eddy simulation studies. Overall, the work establishes a coupled physical and chemical mechanism that governs enhanced preferential transport and provides new insight into ammonia/hydrogen bluff-body flame behavior.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114889"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386877","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":"Extension of jet diffusion flames impinging on metal foam barriers","authors":"Zhiyang Liu,&nbsp;Hongxu Li,&nbsp;Huahua Xiao","doi":"10.1016/j.combustflame.2026.114893","DOIUrl":"10.1016/j.combustflame.2026.114893","url":null,"abstract":"<div><div>Flame extension induced by impingement directly influences the thermal hazards of jet fires. Whereas flame impinging on impermeable surfaces has been extensively studied, the extension of jet diffusion flame impinging on permeable surfaces has not been sufficiently investigated. This study investigates the radial flame extension resulting from hydrogen jet fires impinging on the open-cell metal foam barriers with different pore densities of 20, 40, 60, and ∞ PPI (pores per inch). In the experiment, flames were recorded using a video camera, and flow fields were measured using the Particle Image Velocimetry (PIV) technique. It was found that the reduction in flame extension length beneath the metal foam barrier is due to fuel penetration through the porous barriers. A lower pore density results in a shorter flame extension. In addition, impingement of unburned core at a smaller nozzle-barrier distance leads to a greater fuel loss by penetration and thus significantly reduces the flame extension length by up to 71.5% compared to the metal plate condition. The flame extension beneath a permeable surface is primarily determined by fuel residue, momentum accumulation before impingement, and fuel loss due to penetration after impingement. Theoretical analysis of flame impingement indicates that the dimensionless flame length reduction (<em>R_f*</em>) induced by buoyancy momentum loss is positively correlated with the flame interception ratio (<em>L_H*</em>). A permeability factor (<em>F</em>) is proposed to characterize the effect of the porous barrier, and the flame extension can be well described by an analytical correlation, <em>R_f*</em> ∼ [(1 <em>+</em> <em>F</em>) <em>L_H*</em>]. This work provides further insights into flame impingement.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114893"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386878","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":"Assessing the performance of recent detailed NH3 and NH3/H2 combustion mechanisms","authors":"András György Szanthoffer ,&nbsp;Máté Papp ,&nbsp;Tibor Nagy ,&nbsp;Tamás Turányi","doi":"10.1016/j.combustflame.2026.114878","DOIUrl":"10.1016/j.combustflame.2026.114878","url":null,"abstract":"<div><div>There has been growing interest in applying ammonia (NH₃) as a fuel. It is often combined with hydrogen (H₂), valued for being carbon-free, to compensate for the poor combustion properties of neat NH₃. Over the last decade, numerous detailed NH₃ combustion kinetic mechanisms have been published, but there is no consensus on the best available mechanism. This study quantitatively evaluates the performance of 36 recently published NH₃ combustion mechanisms based on how well they can reproduce indirect experimental data. The utilized experimental data collection includes shock tube ignition delay times (IDT), laminar burning velocities (LBV), and concentrations measured in flow reactors, jet stirred reactors, and shock tubes. With 17,242 data points in 1327 data series from 110 publications, this is, to the best of our knowledge, the most extensive data collection ever used for NH₃/H₂ mechanism testing. The uncertainties of the experimental data were carefully evaluated, and they were considered in assessing the performance of the mechanisms. A novel, generally applicable, model-free approach was proposed to propagate the temperature uncertainty to the measured outlet concentrations, resulting in more realistic errors for the concentration data than in previous comprehensive mechanism testing studies. All utilized experimental data are available in the ReSpecTh database (<span><span>https://ReSpecTh.hu</span><svg><path></path></svg></span>). None of the mechanisms had satisfactory performance for all types of experimental data, but the NUIG-2024 mechanism and the Tsinghua-2024c mechanism demonstrated the best overall performance among the investigated models and were selected for further investigations. Missing third-body efficiencies for NH₃ were added to the third-body reactions of both mechanisms, and their H/O and NH₃ pyrolysis subsets were also replaced. The overall performance of NUIG-2024 could not be noticeably improved by these modifications, whereas modified versions of Tsinghua-2024c had slightly improved performance. However, none of the modifications resulted in a mechanism sufficiently accurate for all types of experimental data, which highlights the need for further NH₃ combustion mechanism development.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114878"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147386886","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":"Characterization and similarity analysis of high-temperature turbulent jets in an aviation kerosene pre-chamber","authors":"Mengnan Zhang,&nbsp;Xuerui Yang,&nbsp;Hu Wang,&nbsp;Zunqing Zheng,&nbsp;Mingfa Yao","doi":"10.1016/j.combustflame.2026.114918","DOIUrl":"10.1016/j.combustflame.2026.114918","url":null,"abstract":"<div><div>To meet the demand for high-efficiency and clean combustion in advanced power systems, Pre-chamber Jet Ignition (PJI) has garnered widespread attention as a highly promising strategy for intensifying ignition. However, for heavy hydrocarbon fuels such as aviation kerosene, the fundamental physical principles governing the PJI process remain to be fully elucidated. In this study, we conducted an experimental investigation into the dynamic characteristics of turbulent jets generated from an aviation kerosene pre-chamber within a constant-volume combustion bomb. The investigation first reveals the system’s inherent robustness to the initial injection pressure. The physical origin of this robustness is attributed to a decoupling between the mixture preparation process and the initial spray momentum. Secondly, through a quantitative analysis of jet velocity fluctuations, a direct correlation is established between the macroscopic behavior of the jet and the evolution of its underlying vortex dynamics. Finally, this study establishes a universal non-dimensional correlation that unifies all experimental conditions. This result reveals a new and complex jet phenomenon governed by the synergistic effect of a dynamic pressure source and secondary combustion. This research not only deepens the understanding of the physical mechanisms governing the PJI process for heavy fuels but also provides a theoretical foundation for the design and optimization of related advanced power systems.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"287 ","pages":"Article 114918"},"PeriodicalIF":6.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387011","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}