Combustion and Flame最新文献

{"title":"Experimental and fuel-surrogates modeling study of the high-pressure pyrolysis of specialty cetane number fuels: implications for fall-off in ethylene unimolecular dissociation","authors":"Mohammed Abdulrahman ,&nbsp;Subharaj Hossain ,&nbsp;Raghu Sivaramakrishnan ,&nbsp;Stephen J. Klippenstein ,&nbsp;P.T. Lynch ,&nbsp;Eric K. Mayhew ,&nbsp;K. Brezinsky","doi":"10.1016/j.combustflame.2025.114222","DOIUrl":"10.1016/j.combustflame.2025.114222","url":null,"abstract":"<div><div>Single pulse shock tube experiments were conducted at 50 atm nominal pressure and 4 ms nominal reaction time over a temperature range of 900–1800 K, to study the pyrolysis speciation of a multi-component jet fuel, F-24, and six cetane number (CN) specialty fuels - CN30, CN35, CN40, CN45, CN50, and CN55. Gas chromatography (GC) was used to qualitatively and quantitatively analyze the post shock gases. The relationship between the formation of key pyrolysis species and the chemically controlled combustion propensity as reflected by the cetane number of each fuel was examined. A surrogate-based mechanism from the CRECK Modelling Group and chemical-functional group based optimized surrogates (CFGO) were used to simulate the pyrolysis speciation results. The model was able to capture the chemistry of most species except two important pyrolysis intermediates – ethylene and acetylene. Chemical kinetic analyses were performed to identify the important reactions which affect the chemistry of these species; however, the rate parameters of critical reactions were found to be unsuitable for simulating the present high-pressure studies. To address this unsuitability, a theory-based fall-off analysis for three reactions representing the decomposition of ethylene and subsequent formation of acetylene was performed, and these are included in an updated version of the CRECK mechanism. This update resolves discrepancies between the experimental results and simulations for ethylene and acetylene. Reaction flux analyses using the updated surrogate model were also performed to identify the important reaction pathways responsible for the formation of crucial species and to provide an analysis of the chemistry of complex multi-component fuel systems. The fundamental reactions responsible for driving pyrolysis chemistry were greatly influenced by the chemical functional groups present in these fuels. In addition to updating the rate parameters of specific reactions to improve modeling, this study also emphasizes the effectiveness of the fuel-surrogate approach, where surrogates representing the chemical functional group composition of the parent fuel serve as a valuable tool for predicting the combustion chemistry of novel fuels.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114222"},"PeriodicalIF":5.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931719","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":"On revised mixture fraction describing multi-stream mixing","authors":"Ziqi Wang,&nbsp;Weijie Zhang,&nbsp;Hai Huang,&nbsp;Jinhua Wang,&nbsp;Zuohua Huang","doi":"10.1016/j.combustflame.2025.114225","DOIUrl":"10.1016/j.combustflame.2025.114225","url":null,"abstract":"<div><div>Multi-stream mixing is common in practice but cannot be modeled using the traditional Bilger mixture fraction defined for only two streams. This work was intended to define the multi-stream mixture fractions that can be adopted in flamelet-tabulated combustion models to simulate the multi-stream mixing and combustion. These mixture fractions are expressed as linear combinations of species mass fractions like the Bilger mixture fraction. The present definition is special as the new mixture fractions are nonconservative and can include the preferential diffusion (PD) effects which were often ignored before. Meanwhile, it can be appliable for any number of inlet streams. The multi-stream mixture fractions are derived based on some basic conserved scalars, like the element mass fractions, enthalpy, and transported scalars. Governing equations for the multi-stream mixture fractions are also presented.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114225"},"PeriodicalIF":5.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927442","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":"Study on combustion characteristics and analysis method optimization of methanol laminar burning under high pressure and high temperature initial conditions","authors":"Peng Wang ,&nbsp;Yang Wang ,&nbsp;Mingfei Lu ,&nbsp;Wuqiang Long ,&nbsp;Pengbo Dong ,&nbsp;Wentao Zhao ,&nbsp;Hua Tian ,&nbsp;Ge Xiao ,&nbsp;Jingchen Cui ,&nbsp;Jianlin Cao","doi":"10.1016/j.combustflame.2025.114215","DOIUrl":"10.1016/j.combustflame.2025.114215","url":null,"abstract":"<div><div>Low-carbon methanol fuel has garnered global interest, and accurately quantifying its laminar combustion characteristics under high-temperature and high-pressure conditions is critical for practical applications. This study investigates the synergistic impact of multiple key parameters on the calculating accuracy of non-stretching methanol flame propagation speed (S_L) and Markstein length (Lb) systematically, including extracting flame radius (<em>EFR</em>) method, time intervals (<em>Ti</em>), flame radius range (<em>FRR:Ri1-Ri2</em>), and extrapolation equations (<em>EE</em>). Schlieren experiments were conducted at 500 K and 0.75–1.25 MPa with CO₂ dilution rates (DR) of 20–30 %, examining three stability cases with Lewis number (<em>Le</em>) is &lt; 1, ≈1, and &gt; 1. Results showed that <em>FRR</em> optimization contributed 63.6 % to S_L accuracy under <em>Le</em> &lt;1 conditions, with <em>Ri2</em> accounted for 35 %. These findings indicate that <em>FRR</em> plays a dominant role in stabilizing flame propagation and minimizing edge effects during combustion. However, as <em>Le</em> increased, <em>FRR</em>’s influence decreased due to reduced flame-core interactions, while <em>EFR</em> and Ti became significant. Specifically, the R_elec method reduced S_L errors more effectively than that of R_area, because it mitigated distortions caused by ignition electrode effects. Optimal time interval (T_s) decreased from 0.75 ms at <em>Le</em> &lt;1 to 0.25 ms at <em>Le</em> &gt;1, reflecting the need for finer temporal resolution to capture rapid instabilities associated with intensified flame wrinkling and cellular formation. EE performance depended on FRR and EFR optimization heavily. These findings demonstrate that the interactions among <em>Ti, FRR</em>, and <em>EE</em> significantly influence the accuracy of S_L calculations, and the optimized Ti and FRR can mitigate errors in <em>EE</em>-based extrapolations effectively. By optimizing key parameters, S_L errors were reduced from as high as 13.4 % to as low as 0.9 %, particularly under unstable combustion conditions. The parameter optimization strategies proposed are expected to provide actionable insights for improving combustion diagnostics, enhancing combustion efficiency, reducing emissions, and advancing methanol engine design.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114215"},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927481","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":"Numerical analysis on non-uniform gas distribution induced conversion of carbon particles during entrained-flow gasification","authors":"Hantao Lu ,&nbsp;Qinghua Guo ,&nbsp;Yan Gong ,&nbsp;Xuning Wang ,&nbsp;Xudong Song ,&nbsp;Guangsuo Yu","doi":"10.1016/j.combustflame.2025.114224","DOIUrl":"10.1016/j.combustflame.2025.114224","url":null,"abstract":"<div><div>During the entrained-flow gasification process, the relative positions of the dilute particle group restrict the diffusion of gaseous reactants between the particles, leading to variations in reaction rates. In this study, the conversion of the double coal char particles moving in hot O₂/CO₂ environments is numerically investigated with pseudo-steady-state (PSS) approach. The double particles are placed parallel to the direction of the gas velocity in laminar flow. The Navier-Stokes equations are applied with energy and species transport model, as well as homogeneous and heterogeneous reaction mechanisms. The influences of the particle distance, particle size and bulk flow velocity corresponding to entrained-flow gasification conditions on reaction characteristics are considered. The results indicate that the space between two particles plays a significant role in restricting gas diffusion. This restriction leads to variations in gas velocity between the windward side and the leeward side of the double-particle system. Stefan flow generated by chemical reactions on the particle surface is initially perpendicular to the particles, and eventually aligns with the bulk flow field in the gasifier, contributing to the overall gas dynamics. When small-size particles (with a radius of less than 0.3 mm) are more widely dispersed, the flame sheet exhibits greater expansion. The overall carbon consumption rates of the double particles rise as the distance between particles and their size increase, with the carbon consumption rate ratio consistently exceeding 1. Higher bulk flow velocity accelerates convective mass transport, resulting in a thinner flame layer on the windward side. Additionally, the increased partial pressure of gaseous reactants elevates the reaction rate, and the higher pressure at elevated Reynolds numbers further enhances particle conversion efficiency.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114224"},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928041","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(25)00238-X","DOIUrl":"10.1016/S0010-2180(25)00238-X","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"276 ","pages":"Article 114200"},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929353","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":"Impact of microwave plasma on burning rate and aluminum agglomeration of composite solid propellant at elevated pressures","authors":"Xiangrui Zou,&nbsp;Yunkai Wu,&nbsp;Wenju Yang,&nbsp;Rui Xue","doi":"10.1016/j.combustflame.2025.114214","DOIUrl":"10.1016/j.combustflame.2025.114214","url":null,"abstract":"<div><div>Traditional solid rocket motors lack flexibility for dynamic thrust modulation, a challenge addressed here through plasma-enhanced combustion, offering a novel approach for thrust control. This study investigates the combustion enhancement of aluminized composite solid propellants under microwave plasma excitation at elevated pressures, aiming to understand the effects of pressure, sodium nitrate doping, and microwave power on propellant combustion. Composite propellants with varying sodium nitrate content were prepared, and the microstructure was characterized using scanning electron microscopy and energy-dispersive X-ray spectrometry. A microwave plasma-assisted high-pressure combustion chamber was developed to conduct experiments, capturing the burning and agglomeration properties of the propellants. Results show that microwave plasma significantly increases the burning rate of the propellant, with enhancements reaching up to 38.2 % at 1 atm and 10.3 % at 7 MPa for propellant with 3.5 wt.% sodium nitrate doping under 1000 W microwave excitation. Notably, a 67 % reduction in agglomerate size was achieved under 7 MPa with a 1000 W microwave field. This burning rate enhancement ratio decreases and the agglomerate size reduction ratio rises with the increase of pressure. It is observed that the burning rate increases and the agglomerate size reduces with decreasing sodium nitrate doping content and raising microwave power. Furthermore, the regulation of propellant combustion by microwave field was verified by firing test of solid rocket motor. The study demonstrates that microwave plasma technology can dynamically regulate propellant combustion under high-pressure condition, offering a promising approach for intelligent energy management in solid rocket motors. The findings pave the way for further development and practical application of microwave plasma combustion enhancement technology in aerospace propulsion systems.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114214"},"PeriodicalIF":5.8,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922741","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":"Surface morphology effects on ignition temperature of single micron-sized Iron particles","authors":"Liulin Cen,&nbsp;Yong Qian,&nbsp;Xingcai Lu","doi":"10.1016/j.combustflame.2025.114216","DOIUrl":"10.1016/j.combustflame.2025.114216","url":null,"abstract":"<div><div>Micron-sized iron particles are promising energy storage carriers for combustion-based power systems, underscoring the critical importance of understanding their combustion performance and reaction kinetics. In this study, sponge iron particles with diameters ranging from 20 to 65 μm, and specific surface areas 4 to 6 times greater than those of spherical iron particles of equivalent mass, were injected into uniform high temperature environments at varying temperatures. High-speed microscopic imaging was employed to capture ignition frequencies with particle size resolution. Experimental results indicate that a small fraction of sponge iron particles can ignite at an ambient temperature of 880 K. When the ambient temperature increases to 1000 K, over 90% of the particles undergo ignition. Within the temperature range of 900–1000 K, the ignition frequency of iron particles increases with particle diameter and is independent of oxygen concentration. A numerical model based on the parabolic law on the growth of the oxide layer shows good agreement with the experimental results. Theoretical analysis reveals that increasing the specific surface area of iron particles can effectively lower their ignition temperature. Notably, iron particles produced through the hydrogen direct reduction of combusted iron oxide particles in iron fuel cycle, which possess significantly higher specific surface areas, are predicted to achieve ignition temperatures as low as 630 K, making them highly advantageous for combustion applications in power systems.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114216"},"PeriodicalIF":5.8,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918438","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 modeling study of the autoignition behavior of a saturated heterocycle: Pyrrolidine","authors":"S. Scott Goldsborough ,&nbsp;Mads C. Jespersen ,&nbsp;Jeffrey S. Santner ,&nbsp;Raghu Sivaramakrishnan ,&nbsp;Hong-Quan Do ,&nbsp;Benoîte Lefort ,&nbsp;Zeynep Serinyel ,&nbsp;Guillaume Dayma ,&nbsp;Luna Pratali Maffei ,&nbsp;Marco Mehl ,&nbsp;Matteo Pelucchi ,&nbsp;William J. Pitz","doi":"10.1016/j.combustflame.2025.114134","DOIUrl":"10.1016/j.combustflame.2025.114134","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Experiments are conducted in both rapid compression machine (RCM) and shock tube (ST) to better quantify autoignition behavior (e.g., ignition delay, heat release) and understand heteroatomic effects in heterocyclic compounds, which are important reference components for the combustion of biomass-derived liquid fuels. These tests focus on the nitrogen-containing, five-membered saturated ring, pyrrolidine, at diluted conditions covering pressures of 20 and 50 bar, temperatures of 720–1450 K and a range of stoichiometries (ϕ = 0.5–2). A chemical kinetic model is developed and coupled to an existing combustion kinetics framework describing key nitrogen containing intermediates (e.g. pyrrole, ammonia and NOx). H-abstraction reactions by OH, H, CH&lt;sub&gt;3&lt;/sub&gt; and HO&lt;sub&gt;2&lt;/sub&gt;, are determined using ab-initio transition state theory methods, while analogies to cyclopentane are adopted for many other reactions, such as ring-opening. The autoignition measurements reveal the lack of negative temperature coefficient (NTC) behavior and low-temperature chemistry for pyrrolidine, as opposed to its saturated hydrocarbon analogue, cyclopentane. Interestingly, at the lowest temperatures (&lt;em&gt;T&lt;/em&gt; &lt; 750 K), the reactivity of cyclopentane is greater than pyrrolidine, while at higher temperatures, pyrrolidine becomes more reactive. Agreement between the experimental measurements and the model is good, and it is found that H-abstraction reactions by HO&lt;sub&gt;2&lt;/sub&gt; and ensuing chemistry play key roles in controlling the reactivity of this cyclic amine. Most of the fluxes, i.e., &gt;70 %, are predicted to move through 1- or 2-pyrroline (C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;7&lt;/sub&gt;N) and then the cyclic C&lt;sub&gt;4&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;N radical, at both lower and higher temperatures, to form either CH&lt;sub&gt;2&lt;/sub&gt;CHCHCHNH via ring-opening or pyrrole via β-scission. It appears that the ring opens more easily at lower temperature whereas the C–H β-scission dominates at higher temperature and lower pressure, such that the reaction of the fuel radical intermediate carrying an unpaired electron on the nitrogen atom with HO&lt;sub&gt;2&lt;/sub&gt; is the next most notable in promoting oxidation.&lt;/div&gt;&lt;div&gt;When comparing pyrrolidine and cyclopentane, which exhibits distinct pathways in different temperature regimes, the pyrrolidine pathways and sensitivity analysis align more closely to the high temperature case of cyclopentane where the important role of HO&lt;sub&gt;2&lt;/sub&gt; radicals is seen to provide chain branching through HO&lt;sub&gt;2&lt;/sub&gt; reaction with the fuel, accompanied by H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; formation and decomposition to OH. The formation of 5-membered diene rings and ring opening reactions are also found to be highly relevant. Of particular note, it is found that there is little influence of small molecule nitrogen-chemistry, e.g., NH&lt;sub&gt;2&lt;/sub&gt;, HCN, NO/NO&lt;sub&gt;2&lt;/sub&gt; on the reactivity of the pyrrolidine mixtures investigated here where no recirculated combustion gases are included.&lt;","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114134"},"PeriodicalIF":5.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903747","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 focus on the first-stage ignition of n-pentane","authors":"Pengzhi Wang ,&nbsp;Jesus Caravaca-Vilchez ,&nbsp;Tibor Nagy ,&nbsp;Shijun Dong ,&nbsp;Xiaobei Cheng ,&nbsp;Karl Alexander Heufer ,&nbsp;Henry J. Curran","doi":"10.1016/j.combustflame.2025.114207","DOIUrl":"10.1016/j.combustflame.2025.114207","url":null,"abstract":"<div><div>It is important to investigate the first-stage ignition of alkane fuels as it is responsible for the cool flame heat release in combustors, particularly engines. In the present study, a new set of ignition delay time (IDT) data of <em>n</em>-pentane is measured in a rapid compression machine (RCM) at <em>φ</em> = 1.0, <em>p</em> = 30 atm, and <em>T</em> = 685–994 K. Moreover, the species concentration profiles of major intermediate species, including alkenes, cyclic ethers, and aldehydes are measured in an RCM at a two-stage ignition condition (<em>T</em> = 730 K) using an updated 2 × fast-acting-valves sampling system. A new kinetic model has been developed to simulate this data. Both the core chemistry and thermochemistry of the low-temperature species associated with <em>n</em>-pentane have been systematically updated. It is found that updating the HȮ₂ + HȮ₂ reaction, which leadstwo ȮH radicals and O₂_, has no obvious influence on the 1st-stage ignition but significantly affects the prediction of the total IDT. This is because ȮH radicals are mainly produced from the formation and consumption of carbonyl-hydroperoxide species before the 1st-stage ignition; HȮ₂ radical recombination and the reaction H₂O₂ (<em>+</em>M) ↔ ȮH + ȮH (<em>+</em>M) become the main source of ȮH radical production only at/after the 1st-stage ignition. The updated thermochemistry data inhibit both the 1st-stage and total IDTs due to the shift towards reactant in the equilibrium of the RȮ₂ ⇌ <span><math><mover><mi>Q</mi><mi>˙</mi></mover></math></span>OOH reaction. The key reactions involved in the low-temperature chemistry are optimized using the Optima++ code within the uncertainty limits of reviewed rate constants in the literature. The present model can predict the experimentally measured data well and shows an improvement compared to previous models.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114207"},"PeriodicalIF":5.8,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902056","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":"Similarity in laminar burning velocity and scaling of turbulent flame speed of real fuel/air expanding flames: RP-3 kerosene with complex compositions","authors":"Linyuan Huang ,&nbsp;Sheng Huang ,&nbsp;Xinke Wang ,&nbsp;Xiaomeng Zhao ,&nbsp;Hui Li ,&nbsp;Quan Zhu","doi":"10.1016/j.combustflame.2025.114209","DOIUrl":"10.1016/j.combustflame.2025.114209","url":null,"abstract":"<div><div>In this study, we analyzed the similarity in the laminar burning velocity of RP-3 kerosene with different components and proposed the scaling of the turbulent flame speed for RP-3 kerosene/air premixed expanding flames. The laminar/turbulent flame propagation characteristics of the RP-3 kerosene/air mixture were measured using a constant volume combustion bomb. The results revealed that despite significant differences in the chemical composition of six RP-3 kerosene samples, their laminar burning velocities exhibited minimal variation under the same conditions. This was attributed to the inherent complexity of real fuels, which makes them less sensitive to the properties of any of their single components. Also, it was also confirmed that this low sensitivity became more pronounced when there were eight or more components in the fuel mixture. Moreover, it was found that the average molecular weights of the small pyrolysis fragments decomposed in the preheating zone were comparable between RP-3 kerosene and some hydrocarbon fuels with large molecular weights (e.g. C4-C8 n-alkanes, iso-octane, iso-cetane, n-decane and decalin). Consequently, they exhibited analogous thermal-diffusional effects. Based on this, it was also found that these fuels had similar normalized turbulent flame speeds under the scaling of the correlation of <span><math><mrow><mrow><mo>(</mo><mrow><mi>d</mi><mo>〈</mo><mi>r</mi><mo>〉</mo><mo>/</mo><mi>d</mi><mi>t</mi></mrow><mo>)</mo></mrow><mo>/</mo><mrow><mo>(</mo><mrow><mi>σ</mi><msub><mi>S</mi><mi>L</mi></msub></mrow><mo>)</mo></mrow><mo>=</mo><mi>A</mi><mi>R</mi><msubsup><mi>e</mi><mrow><mi>T</mi><mo>,</mo><mi>f</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msubsup></mrow></math></span>, and the coefficient (<span><math><mi>A</mi></math></span>) had a pronounced nonlinear relationship with the Markstein number (<span><math><mrow><mi>M</mi><mi>a</mi></mrow></math></span>). Finally, a unified correlation for turbulent flame speed considering the thermal-diffusional effect (<span><math><mrow><mrow><mo>(</mo><mrow><mi>d</mi><mo>〈</mo><mi>r</mi><mo>〉</mo><mo>/</mo><mi>d</mi><mi>t</mi></mrow><mo>)</mo></mrow><mo>/</mo><mrow><mo>(</mo><mrow><mi>σ</mi><msub><mi>S</mi><mi>L</mi></msub></mrow><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mrow><mn>0.0664</mn><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo><mi>M</mi><mi>a</mi><mo>/</mo><mn>2</mn></mrow></msup><mo>+</mo><mn>0.0803</mn></mrow><mo>)</mo></mrow><mi>R</mi><msubsup><mi>e</mi><mrow><mi>T</mi><mo>,</mo><mi>f</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msubsup></mrow></math></span>) based on the Markstein number was proposed, which could describe not only the present experimental data, but also turbulent flame speeds from literature for other fuels under wide conditions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"277 ","pages":"Article 114209"},"PeriodicalIF":5.8,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899441","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}