Applications in Energy and Combustion Science最新文献

{"title":"Liquid ammonia direct injection for internal combustion engine application: A review","authors":"Christine Mounaïm-Rousselle ,&nbsp;Camille Hespel ,&nbsp;Utkarsha Sonawane","doi":"10.1016/j.jaecs.2025.100388","DOIUrl":"10.1016/j.jaecs.2025.100388","url":null,"abstract":"<div><div>Since the 2020s, there has been renewed interest in ammonia as a valuable zero-carbon fuel for Internal combustion engines, given its wide range of potential applications, from the marine sector to off-road machinery. Ammonia's fuel characteristics differ significantly from those of conventional hydrocarbon fuels. Its phase-change properties make liquid-phase ammonia injection a promising approach, as high-pressure injection of liquid ammonia enables efficient and cleaner combustion. High-pressure direct fuel injection offers the advantage of improved atomization through droplet breakup. The subsequent evaporation of these atomized droplets is crucial for the spatial distribution of fuel vapour, local air/ammonia mixing, ignition, and combustion development. However, ammonia tends to undergo flash boiling under injection conditions relevant for an internal combustion engine. In general, flash-boiling atomization enhances liquid evaporation, reduces droplet size, increases spray velocity, and results in longer spray penetration. Since the calorific value of ammonia is approximately half that of conventional fuels, the use of larger nozzle diameters and multi-hole injectors is recommended. While flash boiling has similar effects on both single- and multi-hole injectors, the spray characteristics of multi-hole injectors are largely influenced by plume-to-plume interactions. Therefore, it is recommended to study spray collapse and flash-boiling atomization separately, as they are related but distinct phenomena. The ammonia spray development characteristics are significantly different in the early and later stages of injection, indicating that the influence mechanisms of flash boiling and conventional boiling are completely different. This review summarizes the recent state-of-the-art liquid ammonia injection for engine-relevant conditions, focusing on flash boiling atomization and some discussions about novel optical techniques needed to characterize not only at the macroscopic scale but also at the microscopic scale, to help the development of accurate modelling tools.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100388"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multistage combustion and reaction coupling of micro-sized aluminum particles in hot steam","authors":"Hongming Ding ,&nbsp;Pikai Zhang ,&nbsp;Shangpeng Li ,&nbsp;Samir Boset Rojas Chavez ,&nbsp;Hong Zhang ,&nbsp;Fanrong Ai ,&nbsp;Weixuan Li ,&nbsp;Xiong Chen ,&nbsp;Huangwei Zhang","doi":"10.1016/j.jaecs.2025.100423","DOIUrl":"10.1016/j.jaecs.2025.100423","url":null,"abstract":"<div><div>Aluminum particles, characterized by their high energy density and favorable reactivity, exhibit significant potential for clean energy applications and advanced propulsion systems. This study integrates heterogeneous and homogeneous reactions to comprehensively simulate the combustion of micron-sized aluminum particles in high-temperature, high-pressure steam under constant-volume conditions. Four distinct combustion stages—core melting, oxide layer rupture, core burning, and post-combustion interphase heat transfer—are identified. During the core burning stage, molten aluminum participates in heterogeneous reactions with steam (H₂O), yielding molecular hydrogen (H₂) and alumina (Al₂O₃). Simultaneously, a detailed analysis of the key reaction pathways reveals that vaporized aluminum engages in homogeneous gas-phase reactions that produce oxygen (O₂) through radical-mediated mechanisms (e.g., involving OH, HO₂). A quantitative assessment shows that the Al-O₂ heterogeneous reaction contributes up to about 8 % of the total aluminum consumption. Results further reveal that increasing equivalence ratio extends combustion duration substantially, particularly the stage of oxide layer rupture. At low equivalence ratios, rupture is driven mainly by heat convection from the hot steam, while at higher ratios, it is mainly driven by heat release from heterogeneous reactions. Elevated initial temperatures and pressures markedly shorten both the ignition delay and total combustion duration. These insights deepen the understanding of multiphase aluminum combustion in steam and provide guidance for advancing the design of metal-fueled propulsion systems.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100423"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exhaust gas composition of a combustion engine running with methanol after interacting with a vanadium–tungsten–titanium oxide SCR catalyst","authors":"Erika Croner ,&nbsp;Franz Koschany ,&nbsp;Marian Schenker ,&nbsp;Hans-Philipp Walther ,&nbsp;Olaf Hinrichsen","doi":"10.1016/j.jaecs.2025.100397","DOIUrl":"10.1016/j.jaecs.2025.100397","url":null,"abstract":"<div><div>One of the most extensive and essential issues nowadays is climate change and how to reduce its advance and impact on the environment and human health. Maritime traffic emits a considerable amount of harmful emissions. One possible way to counteract climate change is by adopting renewable and more environmentally friendly combustion fuels, such as methanol (MeOH). However, the current combustion technology does not enable engines to run with 100% MeOH. A MeOH/diesel fuel blend or a diesel pilot injection is required. When using a MeOH/diesel fuel blend, the resulting <figure><img></figure> emissions make the installation of a Selective Catalytic Reduction (SCR) catalyst necessary. This study investigates for the first time the interaction between the exhaust gas emission of a MeOH engine with a vanadium–tungsten–titanium oxide (VTT) SCR catalyst at applicable conditions. Experiments revealed that HCHO is produced through MeOH oxidation. Through further reaction with NH₃, toxic HCN is formed. As NH₃ is consumed, the <figure><img></figure> conversion ( <figure><img></figure> ) decreases accordingly. Unwanted emissions can be reduced by adjusting specific parameters, such as the ratio of NH₃/ <figure><img></figure> (alpha), pressure, space velocity (SV) or water content. Since durability is an important issue in real world applications, a field aged catalyst is evaluated additionally.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100397"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of MXene (Ti3C2) addition on ignition and combustion properties of boron particles","authors":"Andy Huynh ,&nbsp;Yue Jiang ,&nbsp;Mathias Kiefer ,&nbsp;Eunyoung Kim ,&nbsp;Dongwon Ka ,&nbsp;Andrew Demko ,&nbsp;Xiaolin Zheng","doi":"10.1016/j.jaecs.2025.100374","DOIUrl":"10.1016/j.jaecs.2025.100374","url":null,"abstract":"<div><div>Boron (B) offers high gravimetric and volumetric energy densities, making it an attractive solid fuel for energetic applications. However, boron is hard to ignite and burns slowly and incompletely due to the presence of surface B₂O₃, which has a low melting point but a high boiling temperature. Recently, a new class of two-dimensional materials known as MXene (Ti₃C₂) has emerged, exhibiting characteristics that could potentially enhance boron combustion, but this potential has not been previously explored. Herein, we experimentally investigate the ignition and combustion performance of boron particles, Ti₃C₂ nanosheets, and an 80 wt. % B/Ti₃C₂ mixture. We find that the addition of Ti₃C₂ nanosheets enhances both the ignition and combustion properties of boron particles. Specifically, Schlieren images of CO₂ laser ignition experiments show that the B/Ti₃C₂ mixture has a similar ignition delay time as Ti₃C₂ but is shorter than boron, and the mixture produces more gaseous products, indicating more oxidation. Bomb calorimetry measurements show that the B/Ti₃C₂ mixture’s heat of combustion is greater than the linear sum of its components, suggesting a favorable interaction between Ti₃C₂ and boron. Similarly, differential scanning calorimetry shows that the mixture releases more heat overall and has lower onset temperatures than pure boron oxidation. Variable-temperature X-ray diffraction analysis of B/Ti₃C₂ mixture shows the formation of anatase and rutile TiO₂, TiF₂, B₂O₃, and various mixed metal oxides at elevated temperatures due to reactions between boron and MXene or its oxidation products. In conclusion, these results demonstrate that Ti₃C₂ nanosheets, and potentially other MXenes, are effective additives for promoting boron combustion, leading to easier ignition and increased combustion efficiency.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100374"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-phase pyrolysis and combustion characteristics of lithium-ion battery electrolyte components: difference from liquid-based fire hazard classification","authors":"Keisuke Kanayama,&nbsp;Kaoru Maruta,&nbsp;Hisashi Nakamura","doi":"10.1016/j.jaecs.2025.100396","DOIUrl":"10.1016/j.jaecs.2025.100396","url":null,"abstract":"<div><div>Fire safety has become a more serious concern for lithium-ion battery (LIB) applications with their market growth to various usage and operation conditions, especially in the energy and transportation sectors. A well-recognized fire hazard classification of LIB electrolyte solvents is determined based on the liquid phase that strongly reflects phase change properties. This study poses a difference in the potential fire hazard of LIB electrolyte solvents depending on liquid-/gas-phase properties considered by demonstrating fundamental gas-phase pyrolysis and combustion simulations. By assuming a LIB fire scenario where vaporized electrolyte solvents are present, pyrolysis in a perfectly stirred reactor, laminar flame speeds and ignition delay times were simulated for commercially used carbonate ester mixtures, ethylene carbonate (EC)/dimethyl carbonate (DMC), EC/ethyl methyl carbonate (EMC) and EC/diethyl carbonate (DEC), using a chemical kinetic model. Pyrolysis simulations indicated that at “low” temperatures (≲ 600 K), even after 1000 s, which could be attainable during a thermal runaway event, carbonate esters are still dominant components but not pyrolysis products, such as H₂/CO/CO₂/CH₄ for DMC and CO₂/C₂H₄/alcohol for EMC and DEC cases. Simulated laminar flame speeds of EC/DMC/air mixtures were lower than those of EC/EMC/air and EC/DEC/air mixtures at 500 K, having a good correlation with a transport parameter, i.e., thermal diffusivity. The relative fire hazard of LIB electrolyte solvents in terms of gas-phase combustion based on laminar flame speed is opposite to that of liquid-phase classification. A proper flammability classification and key combustion properties need to be considered depending on the expected LIB fire situation.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100396"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bagged ensemble of ANN for predicting laminar flame speed of toluene reference fuels and syngas blends in SI engines","authors":"Vijay Raj Giri ,&nbsp;Jaesung Kwon ,&nbsp;Doohyun Kim","doi":"10.1016/j.jaecs.2025.100390","DOIUrl":"10.1016/j.jaecs.2025.100390","url":null,"abstract":"<div><div>Laminar Flame Speed (LFS) is a critical parameter that determines the burn rate in Spark Ignited (SI) engines, as it influences the laminar burnup process of air/fuel mixture entrained by turbulent flame. For various SI engine modeling approaches, accurate prediction of LFS under engine-relevant conditions is crucial. Syngas, often created from various renewable feedstocks, offers significant potential for mitigating engine knock and engine-out emissions. This study introduces a novel approach using ensembles of neural networks as a non-linear regression method to predict LFS of gasoline surrogates and syngas blends under engine-relevant conditions. To address the scarcity of experimental data, we performed 1-D flame simulations to generate a sufficiently large LFS dataset (225,200 cases in total) which was supplemented by available experimental data in literature. To mitigate the potential bias associated with chemical mechanism selection, multiple kinetic mechanisms were utilized for the flame simulations. Considering the thermodynamic conditions during flame propagation in SI engines, the dataset covers conditions from 300 K to 1000 K, 1 bar to 50 bar, and equivalence ratios from 0.8 to 1.2. Moreover, a large number of Toluene Reference Fuel (mixtures of iso-octane, n-heptane, toluene)/syngas blends up to 11,140 mixtures were explored. After evaluating multiple ML models, a two-hidden-layer neural network was selected for optimal performance. To improve robustness of predicted LFS, the neural network was further refined by employing ensembles of five such neural networks, each separately trained on 80 % of the dataset. The model developed in this study represents a substantial advancement in accurate and computationally efficient LFS prediction. It also introduces an effective approach to account for mechanism-associated bias by utilizing multiple chemical mechanisms.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100390"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal pre-treatment of waste municipal sewage sludge for thermochemical valorizations: An experimental study on moisture reduction and sludge modifications","authors":"Serena Capone ,&nbsp;Katia Gallucci ,&nbsp;Luca Taglieri ,&nbsp;Daniel Mammarella ,&nbsp;Massimiliano Materazzi ,&nbsp;Matteo Stante ,&nbsp;Andrea Di Giuliano","doi":"10.1016/j.jaecs.2025.100405","DOIUrl":"10.1016/j.jaecs.2025.100405","url":null,"abstract":"<div><div>SS valorization by thermochemical conversions (e.g., gasification) for power, heat or fuels production has an interesting development outlook. The literature suggests that SS moisture must be lowered below 20 wt% for conventional thermochemical conversions such as gasification. This work focuses on the experimental investigation of the effects of a thermal pre-treatment of SS with air, addressed to adjusting SS moisture. Semi-batch tests were performed on SS at a laboratory scale (40 g of SS, 2 NL/min air, 2 h, 75–250 °C). The temperature of thermal pre-treatment significantly influenced the elemental composition of solid residue, its moisture content, and the properties of liquid condensate, characterized by unprecedented analyses. Temperatures of 120 °C or higher ensured adequate moisture removal; however, a significant depletion of SS dry solids (C, H, N, S) was quantified above 200 °C. Condensed liquids were beyond Italian legislative limits for direct discharge into the environment. Finally, estimates of the heat contributions to the pre-treatment were performed. The collected results are a first step between fundamental understanding and process design, suggesting that the investigated pre-treatment may fit seamlessly into the schemes of traditional and innovative thermochemical processing plants.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100405"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separation and recovery of biohydrogen using a Pressure Swing Adsorption plant characterized by adsorption of CO2, CO, and CH4: Novel Geometric Control with integral action to mitigate disturbances in a complex process","authors":"Jorge A. Brizuela-Mendoza ,&nbsp;Jesse Y. Rumbo-Morales ,&nbsp;Gerardo Ortiz-Torres ,&nbsp;Felipe D.J. Sorcia-Vázquez ,&nbsp;Jair Gómez Radilla ,&nbsp;Manuela Calixto-Rodriguez ,&nbsp;Estela Sarmiento-Bustos ,&nbsp;Erasmo Misael Rentería Vargas ,&nbsp;Julio César Rodríguez-Cerda ,&nbsp;Jorge Salvador Valdez Martínez ,&nbsp;Mayra G. Mena-Enriquez ,&nbsp;Moises Ramos-Martinez ,&nbsp;R.E. Lozoya-Ponce","doi":"10.1016/j.jaecs.2025.100371","DOIUrl":"10.1016/j.jaecs.2025.100371","url":null,"abstract":"<div><div>70% of carbon emissions (CO₂) are generated from the excessive use of transport and industry. In the race for decarbonizing transport, biohydrogen holds a prominent position as a potential alternative to traditional fossil fuels with zero net emissions. New technologies or processes (Cryogenic separation, Membrane permeation, Electrochemistry, among others) are used to produce biohydrogen. One of the technologies that is gaining interest in research centers and industries is the Pressure Swing Adsorption (PSA) process. However, research is still needed to develop a PSA plant that mitigates disturbances, which directly affect the purity of biohydrogen (99%) that meets the criteria for use as biofuel. This article aims to propose a PSA plant for biohydrogen production using robust controllers (PID and geometric control) to mitigate disturbances and maintain a stable purity above 99%. By using geometric control, the adsorption capacity (molar fraction) increased to 0.55 CO₂, 0.04 CO, 0.04 CH₄ compared to the results obtained without control (0.35 CO₂, 0.021 CO, 0.01 CH₄), achieving a recovery greater than 60% with an energy efficiency of 0.64%. A biohydrogen productivity of 1.55<span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> <span><math><mrow><mo>(</mo><mi>k</mi><mi>m</mi><mi>o</mi><mi>l</mi><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></mrow></math></span> was obtained with a final purity of 0.994 in the molar fraction. On the other hand, PID control presents a low adsorption capacity compared to those obtained with geometric control; likewise, a lower recovery of 55% was obtained, and an energy efficiency of 0.71% was used to obtain a purity of biohydrogen of 0.99 in molar fraction. It is concluded that the geometric control law offers greater robustness and performance in the face of disturbances that occur in a complex process such as PSA. Furthermore, this novel geometric control law produced improved results with a faster response to disturbance rejection, achieving greater productivity and purity, and meeting international standards for use as a biofuel.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100371"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conv-TssNet: A time-domain signal separation network based on cepstral analysis for direct absorption spectroscopy with interference features","authors":"Zhenhai Wang ,&nbsp;Weitian Wang ,&nbsp;Zihao Song ,&nbsp;Xiaoliang Chen ,&nbsp;Pengfei Fu ,&nbsp;Aamir Farooq ,&nbsp;Xing Chao","doi":"10.1016/j.jaecs.2025.100409","DOIUrl":"10.1016/j.jaecs.2025.100409","url":null,"abstract":"<div><div>This work presents Conv-TssNet, a fully convolutional neural network that integrates cepstral analysis for end-to-end separation of overlapping absorption signals directly in the optical time domain. Trained on a large-scale HITRAN-based dataset augmented with realistic baseline perturbations and spectroscopic variability, Conv-TssNet demonstrates robust generalization across diverse gas mixtures and measurement conditions, achieving high-fidelity reconstruction with mean scale-invariant signal-to-noise ratio (SI-SNR) values of 37.2 dB and 40.5 dB for target and background components, respectively. Experimental validation in a premixed CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/air flat-flame burner confirms accurate and repeatable retrievals of temperature and CO concentration, with uncertainties as low as 14 K and 0.14%, respectively. Compared to the interference-feature baseline transform and background subtraction (IFBTBS) method, Conv-TssNet significantly reduces retrieval uncertainties and demonstrates superior noise immunity under turbulence-induced distortions. It maintains temperature deviations below 3.33% with 2.30% uncertainty at a high distortion level (<span><math><mrow><msub><mrow><mi>c</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>=</mo><mn>3</mn><mo>.</mo><mn>0</mn></mrow></math></span>), compared to 7.25% deviation and 5.10% uncertainty with IFBTBS, and accelerates computational speed by approximately 900-fold, enabling real-time, <em>in situ</em> applications. This study represents the first cross-domain adaptation of deep time-domain speech separation architectures to laser absorption spectroscopy, establishing a novel framework for applying deep learning to complex optical diagnostics. Future work will focus on extending the proposed network to multi-species spectral separation, developing integrated retrieval-inference frameworks, and incorporating uncertainty-aware modeling to enhance robustness for practical field deployments.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100409"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145323712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient ignition characteristics of swirling spray kerosene flames under high-altitude relight conditions","authors":"Qian Wang ,&nbsp;Yi Gao ,&nbsp;Peng Zhu ,&nbsp;Chen Fu ,&nbsp;Yifeng Jiang","doi":"10.1016/j.jaecs.2025.100383","DOIUrl":"10.1016/j.jaecs.2025.100383","url":null,"abstract":"<div><div>The effects of low temperature and pressure on the transient ignition process of swirling spray kerosene flames under high-altitude flight conditions were studied experimentally in an optical chamber. The transient flame and flow field variations during the ignition process are observed and analyzed through high-speed direct and schlieren images. Through image enhancement of color flame images, it is found that there are two different development modes in the ignition process. The first mode involves three stages: the formation stage of the fire nucleus, the initial flame kernel propagation stage, and the successful ignition stage. The flame is more likely to be distinguished in the second stage. In the second ignition mode, a flame kernel is formed first, which then propagates both upward and downward to achieve continuous combustion. With the reduction of ambient pressure, the ignition completion time is shortened while the flame height increases significantly. Under the same environmental pressure conditions, the ignition completion time increases slightly under low-temperature conditions. The ignition process and the flame morphology after ignition become more chaotic and irregular under low-temperature conditions, primarily because low temperatures worsen the fuel evaporation and atomization performance, resulting in an uneven distribution of droplets of different sizes. Besides phenomenological observation, quantitative velocity is estimated through schlieren images using an optical flow algorithm. The results indicate that reducing pressure causes the flame to spread faster in the flow field. Under the most extreme low pressure and temperature conditions, dramatic velocity gradients can be observed, which is the leading cause of the ignition failure.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"24 ","pages":"Article 100383"},"PeriodicalIF":5.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}