检索结果-南通市图书馆

Particuology 2024年第2期85卷 241-251页

作者： Yi Liu Yunyan Guo Rui Zhu Jinqiang Zhou Zhengxu Lin Kai Han Chongwei An Jingyu Wang Bidong Wu School of Environment and Safety Engineering North University of ChinaTaiyuan030051China School of Engineering Beijing Institute of TechnologyBeijing100081China Shanxi Province Ultrafine Powder Engineering Technology Research Center Taiyuan030051China

Improved controllability and energy density of ignition agents are of great significance for the devel-opment of energetic composite materials.In this study,droplet microfluidics and emulsification tech-niques were combined to prepare HNS/CL-20 composite microspheres with polyglycidyl azide polymer(GAP)as the binder.The influence of binder content on the morphology of microspheres was investi-gated,and the microspheres were characterized and tested for particle size,crystal structure,thermal decomposition,dispersibility,mechanical sensitivity,combustion behavior and detonation performance.The results showed that microspheres prepared with a binder content of 3%had higher sphericity and particle size uniformity.The microspheres retained the crystal structure of both HNS and CL-20(ε-type).Compared with raw HNS,the microspheres had higher apparent activation energy,better safety per-formance,and good dispersibility.The ignition experiments and detonation performance tests show that HNS/CL-20 composite microspheres have excellent ignition performance,obvious combustion flame,and significant energy release effects,which are expected to achieve high energy and high-speed response of the igniter,thus improving the ignition reliability in special environments or systems.

关键词： Droplet microfluidics Emulsification technology Energetic materials Composite microspheres Crystal phase control ignition

Experimental and Numerical Investigations on ignition and LBO Performances for Staged Combustor under Sub-Atmospheric Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2023年第3期32卷 1251-1262页

作者： ZHAO Qianpeng XU Gang MU Yong YANG Jinhu WANG Kaixing Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of Sciences University of Chinese Academy of Sciences Innovation Academy for Light-duty Gas Turbine

In order to effectively widen the high-altitude operating limits of the multi-swirl staged combustor,the ignition and lean blow-out(LBO)performances of the model combustor were experimentally acquired under the conditions of room temperature and sub-atmospheric pressure with the altitude ranging from 0 km to 12 km.Moreover,the isothermal flow fields inside a staged model combustor with different sub-atmospheric conditions were simulated.Experimental results show that the minimum ignition and LBO fuel-air ratio(FAR)increase rapidly with the increase of simulated altitude.In addition,as the relative pressure drop of injector increases from1%to 3%,the ignition and LBO performances are gradually improved.Side visualization of the flame by high-speed camera shows that the time-averaged flames under stable combustion have a similar distribution pattern under different pressure drops.The luminous intensity is stratified into dim-bright-dim layers along axial direction.The flame near LBO shrinks to the outlet of pilot stage with a great reduction in luminous intensity.The numerical results reveal that with the decrease of air pressure,the air mass flow rate involved in atomization and combustion is significantly reduced,and the aerodynamic shear force of swirling air is weakened,which are adverse to atomization and fuel-air mixing for airblast atomizer and further lead to the deterioration of ignition and LBO performances.

关键词： ignition lean blow-out sub-atmospheric pressure staged combustor airblast atomizer

Flash Lamps as ignition and Initiation Sources of the VS-2 Pyrotechnic Composition

在线全文

学校读者我要写书评

暂无评论

含能材料 2022年第4期30卷 370-378页

作者： Sergey I.Gerasimov Mikhail A.Ilyushin Sergey M.Putis Sergey A.Dushenok Irina V.Shugalei Andrey M.Sudarikov Russian Federal Nuclear Center‑All‑Russian Research Institute of Experimental Physics SarovRussia Sarov Institute of Physics and Technology is a Branch of the Scientific Research Nuclear University MEPhI SarovRussia Nizhny Novgorod State Technical University Named after R.E.Alekseev Nizhny NovgorodRussia RAS Institute for Studying Problems in Mechanical Engineering ‑is a Branch of the RAS Applied Physics InstituteNizhny NovgorodRussia "Technologist"Special Design and Technological Bureau St.PetersburgRussia Saint‑Petersburg State Institute of Technology(Technical University) St.PetersburgRussia Russian State Hydro‑meteorological University St.PetersburgRussia

In the present work it is found that the pyrotechnic composition VS⁃2 can be initiated with flash lamps IFC⁃500 and EVIS.VS⁃2 pyrotechnic composition contains 90%of mercury(Ⅱ)5⁃hydrazinotetrazolate perchlorate and 10%of optically trans⁃parent copolymer of 2⁃methyl⁃5⁃vinyltetrazole and methacrylic acid(PVMT).We have found that the flash lamps make it possi⁃ble to initiate combustion of VS⁃2 composition with its transition to detonation both in cylindrical charges placed in brass caps of 5 mm diameter and 2 mm high,and film charges with 10 mm×80 mm in size and surface weights of 60 mg·cm^(-2)and 90 mg·cm^(-2),showing ignition delay times 10μs and 3μs,respectively.We also measured detonation velocities for VS⁃2 composition film charges,which were 4375-4505 m·s^(-1)(of the charge being surface mass 60 mg·cm^(-2))and 4221-4281 m·s^(-1)(of the charge be⁃ing surface mass 90 mg·cm^(-2))and their blasting action on the aluminum plate.The depths of the normal shock wave imprints at the charge⁃barrier interface were 0.6-0.7 mm(for surface mass of the film charges 60 mg·cm^(-2))and 1.2-1.3 mm(for surface mass of the film charges 90 mg·cm^(-2))

关键词： VS⁃2 pyrotechnic composition flash lamps ignition transition of combustion to detonation blasting action

The surface activation of boron to improve ignition and combustion characteristic

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第9期18卷 1679-1687页

作者： Jian Wang Jun Wang Yaofeng Mao Rufang Peng Fude Nie State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyNo.59Qinglong RoadMianyang CitySichuan621010China Institute of Chemical Materials China Academy of Engineering PhysicsNo.64Mianshan RoadMianyang CitySichuan621999China

Boron is a very promising and highly attractive fuel because of high calorific value. However, the practical applications in explosives and propellants of boron have been limited by long ignition delay time and low combustion efficiency. Herein, nano-Al and graphene fluoride(GF) as surface activated materials are employed to coat boron(B) particles to improve ignition and combustion performance. The reaction heat of nano-Al coated B/KNO_(3)and GF coated B/KNO_(3)are 1116.83 J/g and 862.69 J/g, respectively, which are higher than that of pure B/KNO_(3)(823.39 J/g). The ignition delay time of B/KNO_(3)could be reduced through nano-Al coating. The shortest ignition delay time is only 75 ms for B coated with nano-Al of 8 wt%, which is much shorter than that of pure B/KNO_(3)(109 ms). However, the ignition delay time of B/KNOcoated with GF has been increased from 109 to 187 ms. B coated with GF and nano-Al shown significantly influence on the pressure output and flame structure of B/KNO_(3). Furthermore, the effects of B/O ratios on the pressure output and ignition delay time have been further fully studied. For B/KNO_(3)coated with nano-Al and GF, the highest pressures are 88 KPa and 59 KPa for B/O ratio of 4:6, and the minimum ignition delay time are 94 ms and 148 ms for B/O ratio of 7:3. Based on the above results, the reaction process of boron coated with GF and nano-Al has been proposed to understand combustion mechanism.

关键词： Boron Surface activation ignition Pressure output Combustion mechanism

Influence of anode temperature on ignition performance of the IRIT4-2D iodine-fueled radio frequency ion thruster

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2022年第1期24卷 139-150页

作者：张兴华张振华贾少霞金婷杨景华李龙刘芳芳蔡勇蔡建 Institute of Microelectronics Chinese Academy of SciencesBeijing 100029People's Republic of China Suzhou Nano-Space Dynamics Technology Co.Ltd Suzhou 215000People’s Republic of China

This paper reports the ignition performance of the iodine-fueled radio frequency(RF)ion thruster(IRIT)at different anode temperaturesT_(a0).The experimental results show that the anode temperature plays important role on the ignition process of the IRIT.There were two characteristic temperatures related to the anode:the minimum ignition temperatureT_(i0)and the stable ignition temperatureT_(is),which were much lower than the pipeline temperature and the storage tank temperature.AtT_(a0)

关键词： radio frequency ion thruster iodine propellant ignition deposition sublimation clog

Evaluating ignition and Combustion Performance with Al-Metal- Organic Frameworks and Nano-Aluminum in HTPB Fuel

在线全文

学校读者我要写书评

暂无评论

火炸药学报 2024年第5期47卷 413-421,I0003页

作者： Sri Nithya Mahottamananda Yash Pal Yarravarapu Sai Sriram Subha S Djalal Trache Department of Aerospace Engineering B S Abdur Rahman CrescentInstitute of Science and TechnologyChennai-600048India School of Aeronautical Science Hindustan Institute of Technologyand ScienceChennai-603103India Energetic Materials Laboratory(EMLab) Teaching and ResearchUnit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj El-Bahri16046AlgiersAlgeria

Incorporating aluminum metal-organic frameworks(Al-MOFs)as energetic additives for solid fuels presents a promising avenue for enhancing combustion performance.This study explores the potential benefits of Al-MOF(MIL-53(Al))energetic additive on the combustion performance of hydroxyl-terminated polybutadiene(HTPB)fuel.The HTPB-MOF fuel samples were manufactured using the vacuum-casting technique,followed by a comprehensive evaluation of their ignition and combustion properties using an opposed flow burner(OFB)setup utilizing gaseous oxygen as an oxidizer.To gauge the effectiveness of Al-MOFs as fuel additives,their impact is compared with that of nano-aluminum(nAl),another traditional additive in HTPB fuel.The results indicate that the addition of 15%(mass fraction)nAl into HTPB resulted in the shortest ignition delay time(136 ms),demonstrating improved ignition performance compared to pure HTPB(273 ms).The incorporation of Al-MOF in HTPB also reduced ignition delay times to 227 ms and 189 ms,respectively.Moreover,under high oxidizer mass flux conditions(79—81 kg/(m^(2)s)),HTPB fuel with 15%nAl exhibited a substantial 83.2%increase in regression rate compared to the baseline HTPB fuel,highlighting the positive influence of nAl on combustion behavior.In contrast,HTPB-MOF with a 15%Al-MOF additive showed a 32.7%increase in regression rate compared to pure HTPB.These results suggest that HTPB-nAl outperforms HTPB-MOF in terms of regression rates,indicating a more vigorous and rapid burning behavior.

关键词： ignition combustion enhancement MOF HTPB regression rate

An experimental study on ignition of single coal particles at low oxygen concentrations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2021年第1期15卷 38-45页

作者： Wantao YANG Yang ZHANG Lilin HU Junfu LYU Hai ZHANG Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

An experimental study on the ignition of single coal particles at low oxygen concentrations (XO_(2)<21%) was conducted using a tube furnace. The surface temperature (Ts) and the center temperature (Tc) of the coal par... 详细信息

An experimental study on the ignition of single coal particles at low oxygen concentrations (XO_(2)ignition processes were recorded by a high-speed camera at different XO_(2) values and furnace temperatures Tw. Compared with literature experimental data obtained at a high XO_(2) value, the ignition delay time τi decreases more rapidly as XO_(2) increases at the low XO_(2) region. The responses of Ts and Tc to the variation of XO_(2) are different: Ts decreases while Tc remains nearly constant with increasing XO_(2) at a low XO_(2) value. In addition, τi is less sensitive to Tw while the ignition temperature Ti is more sensitive to Tw at a low XO_(2) value than in air. Observations of the position of flame front evolution illustrate that the ignition of a coal particle may change from a homogeneous mode to a heterogeneous or combined ignition mode as XO_(2) decreases. At a low XO_(2) value, buoyancy plays a more significant role in sweeping away the released volatiles during the ignition process.

关键词： coal particles low oxygen concentration ignition ignition temperature ignition modes

Numerical investigation of the effects of turbulence on the ignition process in a turbulent MILD flame

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第8期37卷 1299-1317,I0002页

作者： Xiang Qian Hao Lu Chun Zou Hanlin Zhang Shujing Shao Hong Yao State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In this study,we conduct three-dimensional nonlinear large-eddy simulation to investigate the interaction between turbulence and reaction during the initial ignition process of a turbulent methane/hydrogen jet-in-hot-coflow flame under moderate or intense low-oxygen dilution(MILD)condition.Special focus has been placed on the spatial development of the flame and the temporal evolution of representative ignition spots that characterize the range of ignition behaviors observed in the case.Results show that the ignition process of the flame consists of four consecutive phases.ignition occurs initially with relatively lean mixtures,and compared to the corresponding homogeneous stagnant adiabatic combustion,the loss of radical species associated with flow transportation causes a delay in ignition.The initial ignition spots formed during the autoignition phase provide sufficient conditions for the stabilization of the flame,including the provision of a variety of key radicals.Results also show that the flow convection accompanying the hot coflow dominated the slow flame propagation,and the turbulent mixing is of great importance for rapid flame propagation.These findings will broaden our knowledge of MILD combustion and provide useful insights into advanced ignition contr.

关键词： MILD combustion ignition Large-eddy simulation

Effect of 2,5-dimethylfuran addition on ignition delay times of n-heptane at high temperatures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2019年第3期13卷 464-473页

作者： Zhenhua GAO Erjiang HU Zhaohua XU Geyuan YIN Zuohua HUANG State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

The shock tube autoignition of 2,5-dimethylfuran (DMF)/n-heptane blends (DMF)/n-100%, by mole fraction) with equivalence ratios of 0.5, 1.0, and 2.0 over the temperature range of 1200-1800 K and pressures of 2.0 atm and 10.0 atm were investigated. A detailed blend chemical kinetic model resulting from the merging of validated kinetic models for the components of the fuel blends was developed. The experimental observations indicate that the ignition delay times nonlinearly increase with an increase in the DMF addition level. Chemical kinetic analysis including radical pool analysis and flux analysis were conducted to explain the DMF addition effects. The kinetic analysis shows that at lower DMF blending levels, the two fuels have negligible impacts on the consumption pathways of each other.As the DMF addition increases to relatively higher levels, the consumption path of n-heptane is significantly changed due to the competition of small radicals, which primarily leads to the nonlinear increase in the ignition delay times of DMF/n-heptane blends.

关键词： ignition delay time shock tube kinetic model 2,5-dimethylfuran (DMF) n-heptane

Enhanced ignition behavior of reactive material projectiles impacting fuel-filled tank

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第4期15卷 533-540页

作者： Shu-bo Liu Ying Yuan Yuan-feng Zheng Chao Ge Hai-fu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

Reactive material projectiles can be an extremely efficient lethality enhancement technology that incorporates the defeat mechanisms of chemical energy and kinetic energy.This paper presents such a research on the enhanced ignition behavior of reactive material projectiles impacting a fuel-filled tank.Firstly,the ignition process description of the fuel-filled tank impacted by inert metal and reactive material projectiles is presented.Secondly,ballistic impact experiments are performed to investigate the ignition effects of the fuel-filled tank impacted by reactive material versus tungsten alloy projectiles with mass matched.The fuel tank used for the experiments is a cylindrical steel casing structure filled with aviation kerosene and sealed with aluminum cover plates on both ends using screw bolts.The experimental results indicate that,compared with impacts from tungsten alloy projectiles,there is dramatically enhanced structural damage to the fuel-filled tank and an enhanced ignition effect caused by reactive material projectile impacts.Finally,an analytical model is developed,by which the effects of the aluminum cover plate thickness on critical structural failure energy of the fuel-filled tank and the total energy of the reactive material projectile deposited into the fuel-filled tank are discussed.The analysis shows a good agreement with the experiments.

关键词： Reactive materials Fuel-filled tank Chemical energy release ignition mechanism