Combustion and Flame最新文献

{"title":"Mechanism of liquid oxygen temperature on combustion stability of gas-liquid swirl coaxial injectors","authors":"Pengjin Cao,&nbsp;Peng Cheng,&nbsp;Xiao Bai,&nbsp;Qinglian Li,&nbsp;Ziguang Li,&nbsp;Jingjing Liao","doi":"10.1016/j.combustflame.2025.114050","DOIUrl":"10.1016/j.combustflame.2025.114050","url":null,"abstract":"<div><div>Deep-throttling variable thrust cryogenic propellants rocket engines are facing the challenge of unstable combustion caused by propellants temperature. To explore the effect of liquid oxygen temperature on the combustion stability of liquid oxygen/methane engine, spray images and CH* chemiluminescence images were obtained synchronously using laser background light imaging. The dynamic characteristics of spray and flame at different liquid oxygen temperatures were studied. The mechanisms of low- and medium-frequency unstable combustion were analyzed. The liquid oxygen temperature has a significant influence on the combustion stability of the gas liquid swirl coaxial injectors. As the liquid oxygen temperature decreases, the frequencies of low- and medium-frequency oscillation combustion modes decrease, and the oscillation intensity increases. Eventually, both the low- and medium- frequency unstable combustion disappear. At the same total mass flow rate, the spray projection area of liquid oxygen decreases with increasing liquid oxygen temperature, while both the flame projection area and flame length increase. The low-frequency oscillation combustion mode results from the interaction between the fluctuating mass flow of liquid oxygen injected into the combustor and the vaporization of liquid oxygen inside the injector. When the liquid oxygen boiling position is near the surface of the gas core, partial vaporization of liquid oxygen inside the injector occurs, leading to the appearance of the medium-frequency oscillation combustion mode in the combustor. However, when the liquid oxygen boiling position exceeds the liquid sheet thickness of the swirl chamber, the liquid oxygen inside the injector remains in a purely liquid phase, resulting in stable combustion. Both low- and medium-frequency combustion instabilities can be effectively suppressed by increasing the combustor pressure or decreasing the liquid oxygen temperature.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114050"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437977","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":"Tracking of acoustic and intrinsic modes for thermoacoustic systems with a general flame model","authors":"Alessandro Orchini ,&nbsp;Frida Cronqvist ,&nbsp;Jakob G.R. von Saldern ,&nbsp;Sylvain C. Humbert ,&nbsp;Jonas Moeck","doi":"10.1016/j.combustflame.2025.113998","DOIUrl":"10.1016/j.combustflame.2025.113998","url":null,"abstract":"<div><div>In a thermoacoustic feedback loop, the flame gain parameter can be used to measure the coupling strength between the acoustic field and the flame response. In this study, it is shown for an arbitrary flame model that the thermoacoustic solutions in the zero-coupling limit split into two distinct sets: modes of (i) acoustic and (ii) intrinsic (ITA) origin. This result was previously shown in a rigorous manner only for <span><math><mi>n</mi></math></span>–<span><math><mi>τ</mi></math></span> flame models, which are special in the sense that they have ITA poles only at infinity. Consequently, all thermoacoustic eigenvalues can generally be calculated from the acoustic and intrinsic poles using continuation methods. In this study, we provide an explicit eigenvalue tracking scheme based on the integration of the local eigenvalue sensitivity to the flame gain parameter. The initial conditions required for integration are considered in detail. While the acoustic poles can be determined directly via Helmholtz solvers, the intrinsic poles are less trivial since they depend on the flame model. An asymptotic expansion of a generic transfer function is derived that is representative of all common flame models. It provides the necessary estimates for the intrinsic poles as the flame gain approaches zero in terms of the Lambert <span><math><mi>W</mi></math></span> function. This approach represents an explicit scheme that guarantees to find all thermoacoustic eigenvalues. The methodology is demonstrated using a simple Rijke tube network model and an experimentally determined state-space model of an annular setup.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 113998"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430079","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":"Energy output characteristics of an enhanced aluminized explosive: Impact of Al-Li alloy fuel","authors":"Jie Yao ,&nbsp;Kanghua Chang ,&nbsp;Fengyou Yang ,&nbsp;Xueyong Guo ,&nbsp;Xiaolu Bi ,&nbsp;Jianxin Nie ,&nbsp;Shi Yan ,&nbsp;Qingjie Jiao","doi":"10.1016/j.combustflame.2025.114064","DOIUrl":"10.1016/j.combustflame.2025.114064","url":null,"abstract":"<div><div>Applying new alloy fuels is critical for improving the energy release characteristics of aluminized explosives. Al-Li alloy fuel has become a promising fuel for metallized explosives due to its low ignition temperature, short ignition delay, and fast combustion rate. In this study, three different Al-Li alloy fuels (Li content 2 %, 5 %, and 10 %) were selected to replace pure Al particles, and their effect on oxidation, ignition, and combustion characteristics were examined. Thermogravimetric-differential scanning calorimetry revealed that using Al-Li alloy can cause early oxidation and increase the oxidation rate and weight gain, which is positively correlated with the Li content. Furthermore, the oxygen bomb calorimeter, closed bomb, and laser ignition measurements revealed that adding Li can promote the ignition and combustion of Al and increase its combustion calorific value. Among them, AlLi₁₀ demonstrated the most balanced combination of high combustion calorific value, high combustion intensity, and short ignition delay. Additionally, aging experiments demonstrated that alloy fuels with more Li content are more easily oxidized, which makes it easy to react with HTPB and affects the safety of explosives. The designed HMX/AlLi₂/HTPB explosive samples demonstrated improved detonation heat, detonation velocity, detonation field temperature, and near-field shock wave overpressure of the explosive when using Al-Li alloy fuel due to the ignition and combustion characteristics of Al-Li alloy fuel. Furthermore, the study explained the energy output structure of highly active alloy fuels in metalized explosive systems and proposed a micro-explosion refinement reaction model of Al-Li alloy fuel in the post-detonation combustion zone. The findings of this study may serve to develop AlLi₂ alloy fuel as an attractive candidate for metalized explosives to enhance energy release.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114064"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438080","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":"Improve energy release of boron by tunable metal-organic frameworks via synergetic micro-explosion and catalysis","authors":"Kang Xue ,&nbsp;Huaiyu Li ,&nbsp;Lun Pan ,&nbsp;Chongjun Li ,&nbsp;Minhua Ai ,&nbsp;Chengxiang Shi ,&nbsp;Xiangwen Zhang ,&nbsp;Ji-Jun Zou","doi":"10.1016/j.combustflame.2025.114062","DOIUrl":"10.1016/j.combustflame.2025.114062","url":null,"abstract":"<div><div>Boron is considered as one of the most promising high energy additives to improve the energy density of aerospace propellants and energetic materials. However, the low energy release properties restrict its practical applications. Herein, three kinds of boron-based composite energetic particles (nB@MOF) were prepared by encapsulating nano boron (nB) in metal-organic frameworks (MOFs) by a self-assembly method with Zn, Co and Mo as metal nodes, and 2-methylimidazole and ethylenediamine as organic ligands. The characterization and dynamics results show that the combustion of organic ligands can induce micro-explosion to destroy the surface oxidation layer of agglomeration and promote the oxidation efficiency of boron. Furthermore, the metal oxide catalyst generated <em>in-situ</em> on nB surface by metal nodes can reduce the initial oxidation temperature and improve the mass transfer distance and interface contact of the oxidation reaction. Compared with nB, the maximum pressurization rate of nB@MOF with 2-methylimidazole as the organic ligand is increased by 31.1 times, the initial oxidation temperature of nB@MOF with Mo as the metal node is reduced by 185.9°C, and the combustion heat of all nB@MOF are increased by more than 1.2 times. This work demonstrates that the energy release properties of boron can be effectively improved by synergistic effect of micro-explosion process and interfacial catalysis.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114062"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430118","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":"Distinct evaporation and combustion behaviors of suspended and unsuspended nanodiesel droplets","authors":"Álvaro Muelas,&nbsp;Taha Poonawala,&nbsp;Javier Ballester","doi":"10.1016/j.combustflame.2025.114060","DOIUrl":"10.1016/j.combustflame.2025.114060","url":null,"abstract":"<div><div>This work reports the main evaporation and combustion characteristics of diesel droplets doped with different concentrations of alumina and ceria nanoparticles (NPs) for a range of conditions scarcely explored and relevant for combustion applications: high-temperature and reducing/oxidizing atmospheres (0/10 % O₂). Due to the potential influence of the particular experimental conditions, all tests are performed using two different setups: a free-falling droplet (FFD) rig and a suspended droplet (SD) facility, following a systematic study that is considered especially pertinent for particle-laden fuels. The reported results demonstrate, for the first time, a great influence of the test method on some of the observed behaviors, which can perfectly justify some contradictions and even inconsistencies observed in previous works. Tests on unsuspended nanodiesel droplets provide smooth evaporation curves until the onset of a single and violent microexplosion that shatters the droplets, whereas the testing of suspended droplets yields a fluctuating evaporation process, with a wide range of sequential disruptive phenomena of different intensities (swelling, puffing, weak microexplosions). These clear differences point to the impact of the suspension filaments on disruptive behaviors for the range of conditions explored, even when very thin ceramic fibers are employed. In spite of these differences, some common features have also been identified. Namely, the addition of NPs does not drive significant changes in the droplet evaporation rate, probably due to the small impact of thermal radiation for the tested conditions. However, the onset of disruptive phenomena shortens the liquid conversion times as compared to neat diesel, with an earlier occurrence as the NP concentration increases, especially for FFD tests. Among the two tested nanoparticles, ceria shows significantly stronger disruptive events and also a progressive reduction in evaporation rate for unsuspended droplets, which is consistent with the formation of a less permeable shell for this kind of NP.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114060"},"PeriodicalIF":5.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437978","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":"Synergy BiF3 and Bi2O3 to enhance the ignition and combustion performance of boron","authors":"Xin-xing Zeng ,&nbsp;Si-jia Yu ,&nbsp;Jun Wang ,&nbsp;Jian Wang ,&nbsp;Yu-qin Gan ,&nbsp;Xian-feng Wei ,&nbsp;Jie Chen ,&nbsp;Xing-quan Zhang","doi":"10.1016/j.combustflame.2025.114037","DOIUrl":"10.1016/j.combustflame.2025.114037","url":null,"abstract":"<div><div>Boron (B), a frequently utilized metalloid fuel, has been garnering growing attention due to its elevated calorific value. However, the inert oxide layer (B₂O₃) on the surface of B powder obstructs the transfer of oxygen, resulting low combustion efficiency and long ignition delay time. In this study, a range of binary oxidizers BiF₃-Bi₂O₃ is developed to enhance the ignition and combustion performance of B by leveraging the synergistic effect of the shell-breaking effect of BiF₃ and the rapid reaction kinetics of Bi₂O₃. A comprehensive investigation is conducted on the influence of the BiF₃/Bi₂O₃ ratio on thermal reaction, ignition delay time, burning rate, and pressure output. The TG-DSC data indicate that the B-BiF₃ reaction exhibits superior gas production capability, while the B-Bi₂O₃ reaction offers greater advantages in terms of heat release. Furthermore, the combination of binary oxidizers (10 wt.%-20 wt.% BiF₃) is more efficient in promoting the ignition and combustion of B than a single metal oxidizer. The B-BiF₃-Bi₂O₃ composite materials exhibit a remarkably high burning rate of 14.81 m/s and a rapid pressurization rate of 1622.45 kPa/s. The enhanced ignition and combustion performance of B-BiF₃-Bi₂O₃ composite materials arises from the synergistic effect between the reactions of B-BiF₃ and B-Bi₂O₃. This study illustrates that the combination of BiF₃ and Bi₂O₃, two types of oxidizers, is an effective method to improve the combustion efficiency of boron.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114037"},"PeriodicalIF":5.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421778","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 validation of a framework to predict the linear stability of transverse thermoacoustic modes of a reheat combustor","authors":"Simon M. Heinzmann ,&nbsp;Harish S. Gopalakrishnan ,&nbsp;Francesco Gant ,&nbsp;Mirko R. Bothien","doi":"10.1016/j.combustflame.2025.114010","DOIUrl":"10.1016/j.combustflame.2025.114010","url":null,"abstract":"<div><div>To achieve fully carbon-neutral, fuel-flexible and on-demand grid power delivery, gas turbines featuring constant pressure sequential combustion architecture show great potential. A sequential combustor is comprised of two axially-staged combustion chambers with the first stage typically being a swirl-stabilised propagating flame. Post first stage combustion, the exhaust stream is first diluted with air and later enriched with additional fuel in the second stage resulting in a vitiated product mixture at high temperatures leading to auto-ignition. Thermoacoustically-stable combustion stages are critical to ensure low emissions, high reliability and ensure mechanical integrity. The second stage firing under auto-ignition conditions can be subject to transversal instabilities. This article presents a finite element coupled method to model the thermoacoustic behaviour of a second stage reheat flame in an efficient, cost-effective approach. To do so, prior techniques to model the response of autoignition-stabilised flames to longitudinal acoustic perturbations is leveraged to quantify the auto-ignition flame’s heat release rate response to transverse acoustic waves. Subsequently, the framework is used to compute the stability of transverse eigenmodes for an atmospheric reheat combustor. Validation is performed by comparison to experimentally obtained pressure sensor measurements and chemiluminescence imaging of the flame. It is observed that the framework can correctly predict the combustor’s unstable first transverse mode and also capture the dynamic flame response qualitatively. Consequently, the framework presented in this work can be leveraged to get reliable and time-efficient stability estimates of the transverse thermoacoustic modes in experimental reheat burners.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114010"},"PeriodicalIF":5.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ab initio kinetics for H-atom abstraction from nitroethane","authors":"Yinjun Chen ,&nbsp;Siyu Cheng ,&nbsp;Longfei Li ,&nbsp;Jiaming Li ,&nbsp;Wenlong Li ,&nbsp;Frederick Nii Ofei Bruce ,&nbsp;Yiheng Tong ,&nbsp;Wei Lin ,&nbsp;Fang Wang ,&nbsp;Yang Li","doi":"10.1016/j.combustflame.2025.114033","DOIUrl":"10.1016/j.combustflame.2025.114033","url":null,"abstract":"<div><div>Nitroethane (NTH) is nitro-containing energetic fuel for detonation engine. The study of the kinetic mechanism of nitroethane combustion is helpful for the development of models of nitrogen-containing energetic materials and provides theoretical support for CFD simulation of detonation engines. H-atom abstraction reactions play a crucial role as chain initiation processes in the detailed chemical kinetic modeling of NTH combustion. Therefore, high-level quantum chemical calculations were performed to determine the rate coefficients for eighteen abstraction reactions, as well as the thermodynamic properties of the species involved. M06–2X/6–311++G(d, p) level of theory was employed for geometry optimization, vibrational frequency calculation, Intrinsic Reaction Coordinate (IRC) analysis, and dihedral angle scans. The QCISD(T)/cc-pVXZ (X=D and T) MP2/cc-pVXZ (X=D, T and Q) and CCSD(T)/cc-pVXZ (X=T and Q) methods with two complete basis set extrapolations are employed for determining the single-point energy (SPE) for all species. The bond dissociation energies (BDEs) of all C-H, C–C, and C-N bonds in NTH were calculated at QCISD(T)//MP2//M06–2X/6–311++G(d, p) level. Rate constants and thermochemistry were carried out based on transition state theory (TST) and statistic thermodynamic theory using Multiwell software. The Master Equation System Solver (MESS) program suite was employed here to calculate the reaction rate constants for complex-forming reactions for ȮH and O₂ system. The reaction energy barriers and reaction rate constants calculated using two methods—QCISD(T)/cc-pVXZ (with X as D and T) and MP2/cc-pVXZ (with X as D, T, and Q), as well as CCSD(T)/cc-pVXZ (with X as T and Q)—show little difference. All results were then incorporated into the PLUG model, which significantly improved predictions for ignition delay time (IDT) as well as the speciation profile in both premixed flames and flow reactors. Sensitivity and flux analyses were conducted to identify the essential reactions controlling reactivity, revealing that H-atom abstraction by ȮH, Ḣ, CḢ₃, and O₂ are the critical reactions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"274 ","pages":"Article 114033"},"PeriodicalIF":5.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422137","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":"Exploring the two-stage ignition of n-butylcyclohexane: A comprehensive experimental and modeling study","authors":"Congjie Hong ,&nbsp;Yuyang Zhang ,&nbsp;Xin Zhang ,&nbsp;Wuchuan Sun ,&nbsp;Qianqian Li ,&nbsp;Zuohua Huang ,&nbsp;Janardhanraj Subburaj ,&nbsp;Aamir Farooq ,&nbsp;Zeimin Tian ,&nbsp;Yingwen Yan ,&nbsp;Jintao Wang ,&nbsp;Yuanhao Deng ,&nbsp;Shilin Zhong ,&nbsp;Yingjia Zhang","doi":"10.1016/j.combustflame.2025.114047","DOIUrl":"10.1016/j.combustflame.2025.114047","url":null,"abstract":"<div><div><em>n</em>-Butylcyclohexane (NBCH) serves as a representative surrogate fuel in investigations concerning the combustion characteristics of both jet fuels and sustainable aviation fuels. Understanding its combustion behavior and developing high-fidelity chemical reaction kinetic models are crucial for fuel performance optimization. In <em>this study</em>, a comprehensive investigation of the oxidation kinetics of NBCH under low-temperature conditions was conducted and a novel experimental dataset including both total and first-stage ignition delay times was proposed. A broad range of experimental conditions was investigated, spanning temperatures from 675 - 1300 K and pressures from 5 - 20 atm, under pure oxygen and air conditions, thereby providing valuable data for numerical validation. An updated chemical kinetic model was developed by integrating the comprehensive core mechanism of NUIGMech 1.3 and 30 fuel layer reaction classes. The proposed model corrected errors in the rate coefficients of key reaction classes identified in previous literature and incorporated the latest rate coefficients from theoretical calculations for specific reaction classes, demonstrating superior performance compared to literature models in accurately predicting the first-stage and total ignition delay times under various operating conditions. Additionally, the model performance was assessed through comparisons with various datasets sourced from the literature. The results showed that the updated model provides accurate predictions across a wide range of parameters. The integration of experimental results and kinetic modeling offers deep insights into the combustion processes of <em>n</em>-butylcyclohexane. This comprehensive approach aids in developing more efficient combustion systems and contributes to the broader understanding of fuel behavior under varied operational conditions.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"274 ","pages":"Article 114047"},"PeriodicalIF":5.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422138","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":"Thermal oxidation and combustion characteristics of single particle AlH3","authors":"Mengxia Sun ,&nbsp;Fang Wang ,&nbsp;Yukun Chen ,&nbsp;Xueqin Liao ,&nbsp;Jianzhong Liu","doi":"10.1016/j.combustflame.2025.114038","DOIUrl":"10.1016/j.combustflame.2025.114038","url":null,"abstract":"<div><div>The oxygen content is a key factor influencing the ignition and combustion performance of AlH₃ particles. This study investigated the thermal decomposition and oxidation characteristics of AlH₃ under different oxygen concentrations using thermogravimetric analysis and differential scanning calorimetry. A tube furnace was used to collect reaction products at various temperatures, and their microstructures and crystal transformations were analyzed to explore the hydrogen release and oxidation mechanisms. Additionally, a settling furnace ignition experimental system was established to study the combustion characteristics and flame morphology of single AlH₃ particles under different oxygen content. The thermogravimetric results indicated that the thermal decomposition and oxidation reactions of AlH₃ under different oxygen concentrations could be divided into one weight loss stage and two weight gain stages. Although the amount and rate of reaction varied among the stages, there was little difference in the degree of oxidation at 1200 °C. The oxidation layer undergoes phase transformations from amorphous Al₂O₃ to γ-Al₂O₃ and finally to α-Al₂O₃, with needle-like structures appearing at 1000 °C. The combustion results showed that when the oxygen concentration is high, particles are prone to micro explosions. Simultaneously observed phenomena such as diffusion flames, growth of oxidation caps, and gas emission. The combustion time of AlH₃ was found to be slightly lower than the empirical values for aluminum, and the ignition delay time was also lower compared to aluminum. Both the ignition delay time and combustion time of the particles decreased with increasing environmental oxygen content.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"274 ","pages":"Article 114038"},"PeriodicalIF":5.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422136","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}