Combustion and Flame最新文献

{"title":"Simplified radiation and soot models for buoyant diffusion flames: Quantitative investigation of fuel mixing effects","authors":"Wenbin Yao,&nbsp;Haidong Liu,&nbsp;Zehua Yang,&nbsp;Xiao Chen,&nbsp;Shouxiang Lu","doi":"10.1016/j.combustflame.2024.113904","DOIUrl":"10.1016/j.combustflame.2024.113904","url":null,"abstract":"<div><div>Simplified radiation and soot models were proposed to provide a simple yet effective method predicting flame radiation and soot characteristics for buoyant diffusion flames. To explore the quantitative effects of fuel mixing and validate the proposed models, LII measurement of soot distribution and multi-point measurement of radiation flux were conducted for different fuel mixtures and different mixing ratios. Characteristic length scales, including the height of soot inception, the height of maximum soot volume fraction and the height of soot oxidation in the soot distributions, were determined by the fuel type and mixing ratio, and resulted in different maximum soot volume fractions. The axial distribution of soot volume fraction, maximum soot volume fraction, soot volume and soot yield can be predicted by the simplified soot model based on the critical mixture fractions. The probability density function of axial soot volume fraction can be described by an exponential function related to the non-sooty probability and maximum soot volume fraction. In addition, flame radiation power presents a linear correlation with soot volume, and flame radiation fraction of buoyant diffusion flame of fuel mixtures presents a linear relationship with the maximum soot volume fraction, which is in agreement with the simplified radiation model proposed in this work.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113904"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102433","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":"An experimental and modeling study on indene oxidation: Emphasizing the competing kinetics between PAH oxidative decomposition and mass growth","authors":"Yuwen Deng ,&nbsp;Zaili Xiong ,&nbsp;Jijun Guo ,&nbsp;Chen Huang ,&nbsp;Long Zhao ,&nbsp;Meirong Zeng ,&nbsp;Zhongyue Zhou ,&nbsp;Wenhao Yuan ,&nbsp;Fei Qi","doi":"10.1016/j.combustflame.2024.113912","DOIUrl":"10.1016/j.combustflame.2024.113912","url":null,"abstract":"<div><div>Fundamental knowledge about the production and oxidation chemistry of polycyclic aromatic hydrocarbons (PAHs) is essential for developing predictive soot models. In contrast to the significant progress in understanding the formation/growth kinetics of PAHs, the detailed oxidation kinetics of PAHs remains to be fully established. This study investigates the oxidation kinetics of indene, the simplest PAH, as a foundational step for examining larger PAHs. Experiments were conducted in a flow reactor at temperatures from 850 to 1350 K, under a pressure of 0.04 atm and an equivalence ratio of 0.5. Characteristic products were quantified using synchrotron vacuum ultraviolet photoionization mass spectrometry, including large resonance-stabilized PAH radicals with 3–4 aromatic rings. Results indicate that even under highly oxidative conditions, the mass growth pathways of indene remain competitive, leading to the production of various large PAHs. This phenomenon is unique to indene oxidation and has not been observed in other bicyclic aromatics. A detailed kinetic model was developed to interpret these findings, revealing that PAH formation is predominantly driven by the indenyl radical. This study further calculates the rate coefficients for the dominant mass growth pathway of indenyl, specifically its self-recombination reaction, to enhance predictions of indenyl and bi-indene. Notably, while spiran and bridging mechanisms are comparably important in cyclopentadienyl mass growth, the spiran mechanism is favored for indenyl, suggesting that the addition of a benzenoid ring significantly alters the reactivity of cyclopenta-like radicals. Comparative analysis with indene pyrolysis experiments reveals that under oxidative conditions, the indenyl radical preferentially decomposes into smaller species, e.g., cyclopentadienyl or cyclopentadiene, thereby enhancing the yields of PAHs that depend on C₅ species as precursors. In the early reaction stage (&lt;1220 K), oxidation reactions promote indenyl formation, thus increasing the proportion of mass growth products. However, at higher temperatures (&gt;1220 K), enhanced oxidation reactions of indenyl lead to its decomposition, outcompeting mass growth reactions and sharply reducing the proportion of mass growth products.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113912"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102618","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":"Role of hydrogen enrichment in ammonia forced ignition at elevated pressures","authors":"Lei Wang,&nbsp;Xingqian Mao,&nbsp;Jinguang Li,&nbsp;Haiqiao Wei,&nbsp;Gequn Shu,&nbsp;Jiaying Pan","doi":"10.1016/j.combustflame.2024.113908","DOIUrl":"10.1016/j.combustflame.2024.113908","url":null,"abstract":"<div><div>Numerous studies have demonstrated that hydrogen enrichment can improve ammonia reactivity, leading to enhanced ignition and combustion performance. However, the role of hydrogen enrichment in forced ignition of ammonia, especially at elevated pressures, remains not fully understood. This study employed a localized energy deposition technique to initiate the forced ignition of ammonia/hydrogen mixtures. The role of hydrogen ratio and ignition energy in ignition and flame kernel initiation was numerically investigated, and the critical ignition conditions were identified by assessing the correlations between heat release and thermal diffusion. The results show that the forced ignition at low pressures involves four traditional stages, whereas only two stages are present at high pressures, i.e., ignition assisted flame kernel propagation and normal laminar flame propagation. The weakening stretching responses at high pressures cause the flame kernel to propagate outward without additional ignition energy. Then deposited ignition energy mainly heats ignition kernels and increases the local temperature, thereby reducing ignition delay time and accelerating ignition initiation. Hydrogen enrichment enhancing ignition performance is mainly due to the changed fuel property and reduced ignition delay time. Kinetic analysis suggests that this enhancement is primarily attributed to the increased sensitivity of H+O₂=O+OH and the substantial H generation from the reverse of NH₃+H=NH₂+H₂, both of which promote the chain branching of H+O₂=O+OH. Besides, successful ignition also depends on the competition between chemical heat release and thermal diffusion. Chemical heat release dominates within a timescale of ∼0.1 ms, while thermal diffusion prevails beyond the threshold. Hydrogen enrichment can significantly reduce minimum ignition energy, but this tendency becomes less pronounced when hydrogen ratio exceeds 20 %.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113908"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102619","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":"Publication / Copyright Information","authors":"","doi":"10.1016/S0010-2180(24)00645-X","DOIUrl":"10.1016/S0010-2180(24)00645-X","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113936"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103013","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":"Tabulated chemistry approach for detonation simulations","authors":"Alexandra Baumgart,&nbsp;Matthew X. Yao,&nbsp;Guillaume Blanquart","doi":"10.1016/j.combustflame.2024.113878","DOIUrl":"10.1016/j.combustflame.2024.113878","url":null,"abstract":"<div><div>Chemistry modeling in detonations typically relies on two broad approaches: simplified models with one- or two-step chemistry, and detailed chemistry. These approaches require choosing between computational efficiency or physical accuracy. To reduce the cost of chemistry while maintaining accurate physics, tabulated chemistry has been used extensively for flames/deflagrations in the low Mach number framework. In the simplest tabulated chemistry model for premixed flames, a progress variable, describing the progress of reactions in the system, is transported in the simulation. This progress variable is then used to look up all other species, transport properties, and thermodynamic variables from a pre-computed table. The present work extends the tabulated chemistry method to detonations. Even in non-reacting compressible flow simulations, the enthalpy and specific heat capacity are required; to describe these thermodynamic variables, the temperature is selected as a second table coordinate. The two table coordinates are able to capture virtually all variations in the progress variable source term. The Zel’dovich–von Neumann–Döring (ZND) model is found to be the most appropriate one-dimensional problem for generation of the table. The ZND tabulation approach is validated for both one-dimensional stable and pulsating and two-dimensional regular and irregular detonations in various <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-<span><math><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> mixtures. The tabulated chemistry simulations are able to reproduce the detailed chemistry results in terms of propagation speed, cellular structures, and source term statistics. For hydrogen detonations, the computational cost of scalar transport is reduced by a factor of 9 and the cost of the chemistry is reduced by a factor of 17. More substantial computational savings are expected for hydrocarbon fuels.</div><div><strong>Novelty and significance statement</strong></div><div>Detonations are often challenging to simulate due to the significant cost of integrating accurate chemical models. In deflagrations, this cost has been reduced by pre-computing the chemistry and collecting the information into a lookup table to be used at runtime. Although chemistry tabulation has been adapted recently for supersonic combustion, such as in scramjets, the typical assumptions of these approaches do not apply to detonations. We propose a new tabulated chemistry approach, valid for detonations and reproducing critical parameters such as induction zone length and detonation velocity. The key novelty lies in (1) the use of progress variable and temperature as the coordinates for tabulation, and (2) the selection of one-dimensional Zel’dovich–von Neumann–Döring detonations as the relevant physical problem to be tabulated. The new model significantly reduces the cost of simulations.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113878"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103025","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":"Detailed validation of LES for H2/CH4/Air deflagrations in an obstructed tube using PIV measurements","authors":"Loïc De Nardi ,&nbsp;Francis Adrian Meziat Ramirez ,&nbsp;Yecine Djebien ,&nbsp;Quentin Douasbin ,&nbsp;Omar Dounia ,&nbsp;Olivier Vermorel ,&nbsp;Thierry Poinsot","doi":"10.1016/j.combustflame.2024.113879","DOIUrl":"10.1016/j.combustflame.2024.113879","url":null,"abstract":"<div><div>This study offers a detailed validation of Large Eddy Simulation (LES) for lean H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/Air deflagrations in an obstructed tube. An exhaustive validation is conducted against detailed measurements from Li et al. (2019), which include pressure traces, flame speeds, and especially, Particle Image Velocimetry measurements of the deflagration-induced flow field. The exercise is performed without adjusting any model parameters, so that all simulations are executed using a unique numerical setup across all test cases. This approach provides a robust and unbiased assessment of LES capabilities in capturing the complex interactions between flame propagation, turbulence, and obstacles in explosion scenarios. Results demonstrate that LES accurately predicts the detailed evolution of the flow field in the recirculation zone behind the second obstacle, and the resulting over-pressure as well as flame speed and flame qualitative shape for various deflagration severities. Such results highlight the potential of LES for improving Safety Computational Fluid Dynamics predictive capabilities in industrial applications involving explosive environments. Once validated, LES is analyzed to unravel flame propagation dynamics: It is demonstrated that the flame remains laminar-like up to the second obstacle and then transitions to the turbulent combustion regime. Independently from the mixture blend, the maximum over-pressure is correlated to flame-turbulence interactions occurring in the wake of the second obstacle. While LES effectively captures these dynamics, it is noted that usual methods to quantify flows in pipes are inadequate for fully characterizing the transition to turbulence: Developing more refined indicators to detect this transition are required.</div><div><strong>Novelty and significance statement</strong></div><div>This study presents a significant advancement in the validation of Large Eddy Simulation (LES) for complex deflagration scenarios within obstructed geometries. Unlike previous works that typically rely on pressure data, flame speeds, and basic visualizations, this research integrates comparisons to Particle Image Velocimetry measurements for a quantitative validation of LES deflagrations in obstructed channels. By leveraging the detailed experimental dataset from Li et al. (2019), this paper establishes a new benchmark for simulation accuracy, demonstrating LES ability to capture complex flame-turbulence interactions in confined spaces. This work not only addresses the critical gap in the literature but also opens the way for advancements in Safety Computational Dynamics, setting a higher standard for future simulation studies.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113879"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102424","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 study of ammonia combustion induced by high reactivity fuel based on optical diagnostics and chemical kinetic analyses","authors":"Mingsheng Wen ,&nbsp;Haifeng Liu ,&nbsp;Shouzhen Zhang ,&nbsp;Zongyu Yue ,&nbsp;Yanqing Cui ,&nbsp;Zhenyang Ming ,&nbsp;Lei Feng ,&nbsp;Mingfa Yao","doi":"10.1016/j.combustflame.2024.113896","DOIUrl":"10.1016/j.combustflame.2024.113896","url":null,"abstract":"<div><div>Ammonia is considered an optimal alternative fuel due to its non-emission of CO₂. However, the use of pure ammonia presents significant challenges. A dual fuel approach utilizing ammonia and high reactivity fuel (HRF) is expected to address these challenges. Nevertheless, the interaction mechanism between ammonia and HRF remains unclear. In the current study, various direct injection (DI) fuels such as n-heptane, n-dodecane, and n-dodecane mixed with 3%_vol 2-ethylhexyl nitrate (EHN) were selected. Optical diagnostic methods and kinetic analyses were employed to investigate the effects of DI fuel reactivity and DI energy ratio on the dual fuel method adopting HRF and ammonia. Experimental results reveal that DI fuel reactivity and DI energy ratio determine the ability to ignite ammonia and influence flame development mode, respectively. Notably, the n-dodecane/EHN blend can operate at a 4% DI energy ratio, with a flame speed of less than 5 m/s, while at a 40% DI energy ratio, the flame speed increases to 10–15 m/s. Emissions at the 40% DI energy ratio include 4373 ppm of NO, 41.4 ppm of N₂O, 71.2 ppm of NO₂, and 6391 ppm of unburned NH₃. Reducing the DI energy ratio from 40% to 20% decreases NO and NO₂ emissions by 14.6% and 7.3%, respectively, while N₂O and unburned NH₃ emissions increase by 129.7% and 105%, respectively. Chemical kinetic analyses suggest that the active atmosphere produced by HRF has a certain impact on reducing ammonia ignition delay in the initial phase of combustion. As combustion progresses, the impacts of the HRF-induced thermal atmosphere on reducing the ammonia ignition delay become more pronounced, with ambient temperature playing a critical role. Furthermore, as the combustion process develops, the influence of ambient pressure on reducing ammonia ignition delay becomes increasingly significant.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113896"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102612","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 computational investigation of pressure effects on soot formation in counterflow diffusion flames of methane in MILD conditions","authors":"Subrat Garnayak ,&nbsp;Prabhu Selvaraj ,&nbsp;Bok Jik Lee ,&nbsp;V. Mahendra Reddy","doi":"10.1016/j.combustflame.2024.113863","DOIUrl":"10.1016/j.combustflame.2024.113863","url":null,"abstract":"<div><div>Moderate or Intense Low-oxygen Dilution (MILD) combustion has been extensively studied as a promising technology to achieve high efficiency and low-emission power generation. The present study numerically investigates the soot formation in non-premixed methane-air flames in MILD conditions at elevated pressures of up to 20 atm. The soot formations under MILD conditions are compared with their conventional counterparts to elucidate the underlying physical and chemical pathways affecting the sooting features. The gas-phase kinetic mechanism is a reduced version of KAUST Aramco PAH Mech 1.0, which has been validated for C₁ and C₂ fuels for the prediction of PAHs (polycyclic aromatic hydrocarbons) species up to coronene (C₂₄H₁₂). A sectional method is used for the soot-aerosol model. The soot formation (SF) flame, with a high strain rate under conventional and MILD combustion conditions, is employed for the investigation. An improved consistent soot model comprising a broad range of precursors from A₂ (naphthalene) to A₇ (coronene) is used for the analysis. The results show that MILD combustion produces an extremely low soot compared to its conventional counterparts at high pressures. The inception rate has a larger contribution towards the overall soot mass growth rate when compared with the HACA rate and condensation rate in MILD conditions. Conversely, the HACA rate is higher than the inception and condensation rates in conventional conditions, suggesting that the soot mass growth rate is HACA rate-oriented. The soot volume fraction and particle number density increase with pressure, and their peak values are positioned near the oxidizer side of the stagnation plane for both conventional and MILD conditions. A rise in pressure increases the major precursors for soot formation, such as benzene (A₁), naphthalene (A₂), pyrene (A₄), and coronene (A₇) in both conventional and MILD conditions. It also enhances the inception, HACA, condensation, and oxidation rates for soot.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113863"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102613","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":"Investigating NO emissions, stability, and flame structure in co-fired premixed NH3/CH4/air swirling flames","authors":"Ayman M. Elbaz ,&nbsp;Zubayr O. Hassan ,&nbsp;Alfaisal M. Albalawi ,&nbsp;Mahmoud MA. Ahmed ,&nbsp;Marwan Abdullah ,&nbsp;Emre Cenker ,&nbsp;William L. Roberts","doi":"10.1016/j.combustflame.2024.113892","DOIUrl":"10.1016/j.combustflame.2024.113892","url":null,"abstract":"<div><div>Ammonia combustion poses challenges due to low reactivity and high NO_x emissions, requiring optimization of combustor designs and fueling strategies. This study examines NO emissions, flame stability, and structure in co-fired premixed NH₃/CH₄/air flames using a double-swirl burner. The inner swirl stream consists of NH₃/CH₄/air mixtures with varying ammonia mole fractions (<em>x</em>_NH3: 0 to 1) and equivalence ratios (Φ_in: 0.4 to 1.4), while the outer stream contains CH₄/air mixtures with Φ_out ranging from 0.5 to 0.8 and Reynolds numbers (Re_out) of 4350, 5250, and 6000. NO emissions varied significantly with Re_out, Φ_in, and Φ_out, prompting further investigation of flame structure using OH-NO PLIF and PIV diagnostics for three flame sets: FA (Φ_in=0.4), FB (Φ_in=0.8), and FC (Φ_in =1.4). Far-rich (FC) and far-lean (FA) flames exhibited an early conical OH layer followed by a V-shaped OH layer, while NO dispersed across the flame, forming a thin layer at the OH boundary with a V-shaped distribution downstream. Higher Re_out facilitated V-OH/NO formation through enhanced mixing, increased recirculation, and more effective ammonia cracking in rich mixtures. At Re_out=4350, the absence of a V-OH layer in FA resulted in reduced NO emissions. Flame FB showed a broader, positively correlated NO and OH structure along the central region of the flame, indicating enhanced NH_i oxidation to NO. Overall, co-firing ammonia with methane in the outer stream was crucial for improving flame stability. To minimize NO emissions, it is important to lower Re_out, increase Φ_out, and avoid premixing NH₃/CH₄ in the inner stream. At high Re_out, limiting rich Φ_in to 1.2 or leaning it out, combined with increasing Φ_out, was the most effective strategy for reducing NO emissions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113892"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102428","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":"Combustion fundamentals on the melt layer of metalized propellants with surface stress evolution","authors":"Hong-Suk Choi,&nbsp;Jack J. Yoh","doi":"10.1016/j.combustflame.2024.113893","DOIUrl":"10.1016/j.combustflame.2024.113893","url":null,"abstract":"<div><div>While progress has been made in the modeling of burning surface of solid propellants, the intricate interactions within the melt layer involving three distinct phases and multi-materials remain unresolved and present a formidable challenge. This study aims to present a comprehensive analysis on the combustion characteristics of metal-added propellants that considers reactive metal particles of random size. Three pivotal techniques are developed for 1) tracking the dynamics of two-phase interface with deforming material boundaries between reactive particle and binder, 2) incorporating the full stress field evolution within each particle, and 3) introducing the phase and composition identifiers to monitor the process of reaction via oxide cap formation, heat transfer between multi-materials, and agglomeration of metal oxide. To address the stability constraint on an explicit time integrator, both normal-size and scale-up simulations of heterogeneous particle packing models are developed using dimensionless numbers. The contours depicting pressure, temperature, stress, and material phase reveal the emergence and expansion of the melt layer, which includes isolated solid reactants with a multi-phase oxide cap and vaporized binder separated from the unburnt region. The quantitative weight fraction analysis delineates and provides insights on the three distinct sections, demarcated by predominant shifts in material phases. The results of the homogeneous model are compared to the reference data as well as heterogeneous model to validate the accuracy. The simulation successfully replicates the visual images taken from experiments without the need for complex mathematical models.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113893"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102430","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}