ACTA ASTRONAUTICA
·
2013
·
IF 0.701
Jian-zhong Liu,Jian-fei Xi,Wei-juan Yang,You-rui Hu,Yan-wei Zhang,Yang Wang,Jun-hu Zhou
Boron is an attractive fuel for propellants and explosives because of its high energy density . However, boron particles are difficult to combust because of inhibiting oxide layers that cover the particles. The use of magnesium as additives has been shown to promote boron oxidation . In this study, laser ignition facility and thermobalance were used to investigate the effect of magnesium on the burning characteristics of boron particles. The influences of magnesium addition on sample combustion flame , boron ignition delay time, boron combustion efficiency and initial temperature of boron oxidation. Results show that all Mg/B samples exhibit the same type of flame structure, i.e., a bright plume surrounded by green radiation which is interpreted as BO 2 emission. The combustion flame intensity of a sample increases with the increasing magnesium content of boron particles. An increase in magnesium content results in a decrease and a subsequent increase in boron ignition delay time. (Mg/B) 0.2 has a minimum ignition delay time of ~48 ms. Boron combustion efficiency increases with increasing magnesium addition. (Mg/B) 0.5 shows a maximum boron combustion efficiency of ~64.2%. Magnesium addition decreases the initial temperature of boron oxidation.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Lei Shi,Ping Xu,Rui Wang,Weixin Tang,Tao Ding,Rongpei Jiang,Changhua Zhang
Ignition delay times of JP-10 in air and the vitiation effect of NO 2 on JP-10 autoignition at high temperatures were investigated behind reflected shock waves. The experiments were carried out at pressures of 2 and 10 atm, temperatures between 900 and 1460 K, fuel lean and stoichiometric conditions with and without 1.0 % NO 2 . The experimental results show that the ignition delay times of JP-10/air decrease with the increase of pressure or the decrease of equivalence ratio. The effect of adding 1.0 % NO 2 is pressure dependence. At 10 atm, the addition of NO 2 promotes the ignition of fuel, which shortens the ignition delay time. At 2 atm, the addition of 1.0 % NO 2 inhibits the ignition of JP-10, which prolongs the ignition delay time. A chemical kinetic mechanism of JP-10/NO 2 consisting of 290 species and 1768 reactions was developed by extending from a C0-C5 alkane and a cyclopentene sub-mechanism. The proposed mechanism has been well validated by ignition delay times, laminar flame speeds and species concentration profiles from literature. To further investigate the autoignition of JP-10 and the vitiation effect of NO 2 , kinetics analyses including reaction pathways and sensitivity coefficients were performed by the developed mechanism. The main consumption pathways of JP-10 in air are H-abstraction reactions from JP-10 by HO 2 radicals. With 1.0 % NO 2 vitiation, the addition of NO 2 has a strong effect on JP-10 consumption via the H-abstraction pathway JP-10 + NO 2 = C 10 H 15 + HONO, which further affects the autoignition of JP-10.
研究领域:
燃烧学
·
化学动力学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2019
·
IF 4.12
Baozhong Zhu,Fan Li,Yunlan Sun,Yuxin Wu,Wei Shi,Weikang Han,Qichang Wang,Qi Wang
Micron-sized aluminum powder exhibits difficulties in ignition and burnout in steam. To overcome these problems, we added various sodium fluoride contents to micron-sized aluminum powder in steam at 800, 900, and 1000 °C to assess their effects on ignition and combustion performances. The ignition delay times, ignition temperatures , and combustion characteristics of all samples were measured primarily using two high-temperature tube resistance electric furnace systems. The experiments showed that adding sodium fluoride to micron-sized aluminum powder decreases its ignition delay time and temperature. Moreover, the ignition delay time and temperature of aluminum powder with addition of sodium fluoride decreases considerably when the temperature increases. For this study, the components and morphology of solid combustion products were obtained using X-ray diffraction and scanning electron microscopy. The combustion efficiency was measured volumetrically using a specially designed apparatus. The obtained combustion efficiency was found to increase with the amount of sodium fluoride added and increase in the temperature. The relationship among the parameters related to combustion characteristics and product characterization was examined in detail to reveal the combustion mechanism.
研究领域:
能源科学
·
材料科学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Zujun Zheng,Yiwei Li,Lei Shi,Dongdong Chen,Changhua Zhang,Jingbo Wang,Ping Li
Indene is an important intermediate in the ring growth process of polycyclic aromatic hydrocarbons (PAHs) which are soot precursors in the fuel combustion . Ignition delay times of indene/3.3% O 2 /Ar and indene/air mixtures were measured behind reflected shock waves over temperatures of 1098–1618 K, pressures of 2.5–10.0 atm, and equivalence ratios of 0.5, 1.0 and 2.0. An Arrhenius-type formula can describe all the measured indene/3.3% O 2 /Ar ignition delay data. But three Arrhenius-type formulas were used to describe the measured indene/air ignition delay data for three pressures because the activation energy varies with different ignition pressures. Indene ignition characteristics in different dilution conditions were compared and discussed. Current results show that the indene ignition delay follows τ ∝ Φ + n diluted in Ar with fuel-lean mixture igniting the fastest and τ ∝ Φ −n at real fuel-air condition with fuel-rich mixture igniting the fastest. For indene/air, when the pressure increases, the effect of equivalence ratio on ignition becomes stronger and the sensitivity of ignition to the variation of temperature becomes weaker. Furthermore, an indene combustion mechanism was developed. The predictions of the developed mechanism are in good agreement with the measured data. Reaction pathway and sensitivity analyses were carried out to determine reaction pathways during the ignition process and dominate reactions which affect ignition delay times. Current experimental results are useful for understanding the ignition properties of indene and studying the formations of larger PAHs and soot. To our knowledge, experimental ignition delay times and a detailed combustion mechanism for indene are firstly reported in this work.
研究领域:
燃料化学
·
燃烧动力学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Fan Li,Baozhong Zhu,Yunlan Sun,Wei Tao
Hydrogen generation by means of the combustion of aluminum powder with sodium borohydride (NaBH 4 ) addition in steam was studied by a pipe furnace at different temperatures. The ignition temperature and the maximum combustion temperature were obtained by an S-type thermocouple . Ignition delay times and combustion efficiencies were measured. The results show that aluminum powder is not ignited at 450 °C, but aluminum powder with NaBH 4 addition is ignited under the same condition. The addition of NaBH 4 significantly decreases the ignition delay time of aluminum powder. Moreover, the ignition delay times of aluminum powder without or with NaBH 4 addition can decrease with increasing the temperature. Combustion products were analyzed by scanning electron microscopy, X-ray diffraction and a portable hydrogen analyzer. The results indicate that NaBH 4 displays a key influence on hydrogen generation. Especially, for aluminum powder with 7 wt% NaBH 4 addition, the obtained maximum volume concentration of hydrogen is about 21,000 ppm at 650 °C.
研究领域:
能源科学
·
材料科学
✓ 已验证
DOI
高影响因子
AEROSPACE SCIENCE AND TECHNOLOGY
·
2025
·
IF 5.8
Fanggang Zhang,Lei Luo,Jiahui Zhang,Weiguang Cai,Shu Zheng,Xingyan Tang,Wenzhe Cai,Ran Sui
Improving the ignition performance of aviation fuels in high-altitude environments is essential for the reliable operation of aero-engines. This study investigated the catalytic ignition of RP-3 aviation fuel at high-altitudes using Co 3 O 4 nanoparticles and fuel-soluble catalysts (platinum and palladium acetylacetonates). Ignition delay times (IDT) and ignition probabilities (IP) were measured in situ using thermocouples and a spectrometer. The results demonstrated that the addition of 150 ppm Co 3 O 4 nanoparticles exhibited the best catalytic performance, achieving 100% IP with the shortest average IDT of 1.41 s. In contrast, the IP of RP-3 without catalysts was only 25%, with an average IDT above 15.92 s. The fuel-soluble catalysts also significantly improved the ignition performance. With 150 ppm addition, both cases reached 100% IP but longer IDTs than that of Co 3 O 4 . Thermogravimetric analysis indicated that Co 3 O 4 nanoparticles catalyzed ignition through the Mars-van Krevelen mechanism at lower temperatures, while at higher temperatures they decomposed into CoO and O 2 , further facilitating ignition through both catalytic effect and the increased amount of oxidant. On the other hand, the fuel-soluble catalysts decomposed into noble metals or their oxidants that provided active sites for the surface oxidation of the fuel, with the heat release from this process initiating gas-phase ignition. These results provide a new strategy for ignition enhancement of aviation fuels in extreme environments via catalytic combustion.
研究领域:
化学工程
·
航空航天工程
·
催化科学
✓ 已验证
DOI
高影响因子
ENERGY
·
2021
·
IF 7.147
Wei Shi,Yunlan Sun,Baozhong Zhu,Jianzhong Liu
To improve the ignition and combustion performance of micron-sized aluminum powder (m-Al) in CO 2 , a self-made pipe furnace experimental platform was established to study the effects of sodium fluoroaluminate (Na 3 AlF 6 ) on the ignition delay times, combustion processes , combustion efficiencies , and combustion products of 1–2, 5, and 30 μm aluminum (m-Al 1 , m-Al 5 , and m-Al 30 ) powders in CO 2 at 1000 °C. The combustion phenomenon was recorded by a high speed camera. The ignition delay time was obtained by post-processing the sequential images. m-Al containing Na 3 AlF 6 has a lower initial reaction temperature and a shorter ignition delay time than those of m-Al without Na 3 AlF 6 addition. The effect of Na 3 AlF 6 content on the ignition delay time is different for m-Al with different sizes. The ignition delay times for m-Al 1 and m-Al 5 increase with increasing the Na 3 AlF 6 content, while the corresponding values of m-Al 30 first increase and then decrease. The combustion products were subjected to the analyses of morphology, composition, and combustion efficiency. The oxidation shell of Al is fluorinated by Na 3 AlF 6 , thereby promoting its ignition and burning. The combustion efficiency of m-Al is significantly enhanced, especially for m-Al 30 . The effect mechanism of Na 3 AlF 6 on the ignition and combustion of m-Al in CO 2 was discussed.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Yanlei Shang,Jinchun Shi,Hongbo Ning,Runtong Zhang,Hongyan Wang,Shengnian Luo
Ignition delay times for methane/nitromethane binary fuels with oxygen diluted in Ar ( CH 4 / CH 3 NO 2 / O 2 /Ar mixtures) are measured with a heated shock tube behind the reflected shock wave at 995–1962 K and 4–18 atm for different equivalence ratios (0.5, 1.0, and 2.0). Blending ratios for CH 3 NO 2 are varied (0, 0.1, 0.2, 0.5, and 1) to investigate the promotion of CH 3 NO 2 on CH 4 during the ignition process. OH ∗ emission histories at a sidewall are used to determine the measured ignition delay times of the binary fuels mixture. Correlations for the measured ignition delay times are obtained using multiple linear regression as a function of pressure, temperature, blending ratio, and equivalence ratio. Experimental results show that a small addition of CH 3 NO 2 dramatically reduces the ignition delay times of CH 4 , and induces a weak two-stage ignition. Three literature mechanisms are examined and compared with the measured ignition delay times for CH 4 / CH 3 NO 2 binary fuels mixtures, and the mechanism from Mathieu et al. is updated and validated against the experimental data. In this mechanism, the rate constants for some important reactions are theoretically determined by quantum chemical calculation. In addition, sensitivity analysis and reaction pathway analysis as well as rate of production are carried out to further elucidate the promotion of CH 3 NO 2 on ignition of the CH 4 .
研究领域:
化学动力学
·
燃烧科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Beilin Zuo,Shuai-Zhong Wang,Sulan Yang,Peijin Liu,Qi-Long Yan
In this work, Si@NC/AP and Si@PVDF/CL-20 composites with different Si contents have been fabricated by spray-drying technique. The flame structure, ignition delay time and combustion process have been investigated. It has been shown that the ignition delay of Si-based fuel with 40 wt% of Si is the shortest. This means that oxygen balance and the catalytic effect of Si on the energetic composites are playing a dominant role during the combustion processes of these composites. The solid composite propellants (SCP, named as SCP-1 and SCP-2) contains two typical Si-based composites Si-80@NC/AP and Si-80@PVDF/CL-20 have been prepared for propellant applications. Their propellants containing the corresponding mechanical mixtures (named as SCP-3 and SCP-4) have been fabricated as a comparison. It has been observed that the cross sections of propellants containing Si-based composites are denser than that of the reference propellants. The burn rate of SCP-1 (with Si-80@NC/AP) and SCP-2 (with Si-80@PVDF/CL-20) are 5.74 and 5.10 mm s −1 at 2.0 MPa, respectively, which are lower than those of the reference samples SCP-3 (6.51 mm s −1 ) and SCP-4 (5.70 mm s −1 ). However, the pressure exponent of former is slightly lower than that of the latter. Moreover, the combustion products (CCPs) of SCP-1 and SCP-3 are more fluffy and smaller in particles size than those of SCP-2 and SCP-4. This indicates that the core-shell structured composites have much better combustion performances due to better heat and mass transfer between the oxidizers and Si as fuel.
研究领域:
材料科学
·
燃烧学
·
推进剂技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 41
·20664-20672
·
IF 7.443
Wenquan Zhang,Xiujuan Qi,Shi Huang,Jinshan Li,Qinghua Zhang
Two series of super-base-derived hypergolic ionic liquid materials were synthesized and fully characterized by 1H and 13C NMR, IR spectroscopy, and high resolution mass spectrometry (HRMS). Their physicochemical properties such as thermal properties, density, viscosity, heats of formation, specific impulse, and ignition delay time were intensively characterized or calculated. Among fourteen new organic ionic materials, eleven salts are liquids at room temperature, which all exhibit good stability to heat and expected hypergolic properties upon contact with WFNA. The densities of these ionic compounds range from 1.00 to 1.22 g cm−3, and their heats of formation vary between −38.0 and 478.6 kJ mol−1. Surprisingly, most of these new ionic liquids exhibited an unexpected thermal stability of >280 °C, in which salt 1 gave the Td value of 310 °C, which is superior to those of any known hypergolic ionic liquids. As a new class of hypergolic fuels, these novel ionic liquid materials have some unique advantages compared to traditional propellant fuels like hydrazine and its derivatives, including extremely low vapour pressure, short ID time, high thermal stability, etc., thereby demonstrating their potential applications as green fuels in liquid bipropellant formulations.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2025
·
IF 7.7
Jie Yao,Hao Liu,Wei Liu,Jianxin Nie,Shi Yan,Xueyong Guo
Metal fuels are widely used in energetic materials to improve their energy release. Al Si alloy fuel is an aluminum-based alloy fuel, and its slow reaction rate limits its potential application in energy material systems. Herein, Al-Si-Mg AlSi9Mgx alloy fuel had been designed and successfully prepared by gas atomization to achieve excellent reactivity characteristics. The reaction characteristics of the fuel were systematically measured by thermal analysis (TG-DSC), bomb calorimeter, volumetric explosion vessel system and laser ignition measurement. Due to the addition of highly active magnesium, the activation energy of alloy fuel was reduced, and the combustion efficiency was increased to more than 99 %, and the ignition delay time was reduced by 6.7 ms and 33.6 ms respectively. Combustion of potassium perchlorate (KP) mixtures shows that AlSi9Mgx alloy fuels had a faster flame propagation rate, 22.814 mm/s and 42.543 mm/s. The superior reaction properties of AlSi9Mgx alloy fuel are due to the presence of internal solid solution Mg or low melting point alloy compound. This work and design provide a reliable method for optimizing the energy output of alloy fuels.
研究领域:
材料科学
·
能源工程
·
冶金学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Xiandie Zhang,Qingqing Zeng,Jie Ji,Haozhe Li,Xinwen Ma,Weiduo Fei,Xiaode Guo,Xiang Zhou
In recent years, metal fluorides are increasingly being investigated as promising oxidants in aluminum-based (Al-based) composite energetic materials to improve the ignition and combustion performance, mainly because of their reaction with the otherwise inert alumina shell. However, the hygroscopicity and relatively high cost of many metal fluorides limit their wide applications. In this work, an effective and mild solvothermal method employing inexpensive raw materials is used to synthesize the otherwise costly anhydrous FeF 2 . A novel Al/FeF 2 energetic composite is then prepared using ultrasound-assisted physical mixing and compared with other more common formulations (Al/PTFE, Al/FeF 3 , Al/Fe 2 O 3 , and Al/FeO) in terms of energetic characteristics. Electric ignition and constant-volume combustion tests show that Al/FeF 2 has a shorter ignition delay time than that of Al/PTFE, as well as a much faster reaction rate and a much greater pressure output capacity than each of Al/FeF 3 , Al/Fe 2 O 3 , and Al/FeO. High-speed photography demonstrates the large flame area and short flame duration of Al/FeF 2 . Moreover, thermal analysis reveals the superior exothermic enthalpy of Al/FeF 2 .Overall, anhydrous FeF 2 prepared in this study shows excellent application potential in Al-based composite energetic materials.
研究领域:
材料科学
·
能源与燃料化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）