期刊文献+
共找到484篇文章
< 1 2 25 >
每页显示 20 50 100
One stone two birds:electrochemical and colorimetric dual-mode biosensor based on copper peroxide/covalent organic framework nanocomposite for ultrasensentive norovirus detection 被引量:1
1
作者 Guobao Ning Quanmei Duan +6 位作者 Huan Liang Huifang Liu Min Zhou Chunlan Chen Chong Zhang Hui Zhao Canpeng Li 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期920-931,共12页
Norovirus(NoV)is regarded as one of the most common causes of foodborne diarrhea in the world.It is urgent to identify the pathogenic microorganism of the diarrhea in short time.In this work,we developed an electroche... Norovirus(NoV)is regarded as one of the most common causes of foodborne diarrhea in the world.It is urgent to identify the pathogenic microorganism of the diarrhea in short time.In this work,we developed an electrochemical and colorimetric dual-mode detection for NoV based on the excellent dual catalytic properties of copper peroxide/COF-NH_(2)nanocomposite(CuO_(2)@COF-NH_(2)).For the colorimetric detection,NoV can be directly detected by the naked eye based on CuO_(2)@COF-NH_(2)as a laccase-like nonazyme using“peptide-NoV-antibody”recognition mode.The colorimetric assay displayed a wide and quality linear detection range from 1 copy/mL to 5000 copies/mL of NoV with a low limit of detection(LOD)of 0.125 copy/mL.For the electrochemical detection of NoV,CuO_(2)@COF-NH_(2)showed an oxidation peak of copper ion from Cu^(+)to Cu^(2+)using“peptide-NoV-antibody”recognition mode.The electrochemical assay showed a linear detection range was 1-5000 copies/mL with a LOD of 0.152 copy/mL.It's worthy to note that this assay does not need other electrical signal molecule,which provide the stable and sensitive electrochemial detection for NoV.The electrochemical and colorimetric dual-mode detection was used to detect NoV in foods and faceal samples,which has the potential for improving food safety and diagnosing of NoV-infected diarrhea. 展开更多
关键词 NOROVIRUS Specific peptides Electrochemical and colorimetric assay dual-mode Copper peroxide/covalent organic framework
在线阅读 下载PDF
A utility and easily fabricated dual-mode fiber film for efficient and comfortable thermal management
2
作者 Jiyuan Yu Jian Zheng +3 位作者 Wei Wang Zhijia Zhu Chunyan Hu Baojiang Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期394-405,共12页
Nowadays, the global climate is constantly being destroyed and the fluctuations in ambient temperature are becoming more frequent. However, conventional single-mode thermal management strategies(heating or cooling) fa... Nowadays, the global climate is constantly being destroyed and the fluctuations in ambient temperature are becoming more frequent. However, conventional single-mode thermal management strategies(heating or cooling) failed to resolve such dynamic temperature changes. Moreover, developing thermal management devices capable of accommodating these temperature variations while remaining simple to fabricate and durable has remained a formidable obstacle. To address these bottlenecks, we design and successfully fabricate a novel dual-mode hierarchical(DMH) composite film featuring a micronanofiber network structure, achieved through a straightforward two-step continuous electrospinning process. In cooling mode, it presents a high solar reflectivity of up to 97.7% and an excellent atmospheric transparent window(ATW) infrared emissivity of up to 98.9%. Noted that this DMH film could realize a cooling of 8.1 ℃ compared to the ambient temperature outdoors. In heating mode, it also exhibits a high solar absorptivity of 94.7% and heats up to 11.9 ℃ higher than black cotton fabric when utilized by individuals. In practical application scenarios, a seamless transition between efficient cooling and heating is achieved by simply flipping the film. More importantly, the DMH film combining the benefits of composites demonstrates portability, durability, and easy-cleaning, promising to achieve large-scale production and use of thermally managed textiles in the future. The energy savings offered by film applications provide a viable solution for the early realization of carbon neutrality. 展开更多
关键词 Micro-nanofiber film dual-mode Comfortable thermal management Simplified production UTILITY Energy saving
在线阅读 下载PDF
NOVEL MICROSTRIP DUAL-MODE BANDPASS FILTER WITH COUPLING ENHANCEMENT AND WIDEBAND SPURIOUS RESPONSE SUPPRESSION
3
作者 张雷 洪伟 周健义 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第4期379-387,共9页
The microstrip dual-mode filter (DMF) with conventional coupling structure has some limitations in- eluding the port coupling strength limited by fabrication tolerance and the existence of serious second order spuri... The microstrip dual-mode filter (DMF) with conventional coupling structure has some limitations in- eluding the port coupling strength limited by fabrication tolerance and the existence of serious second order spuri- ous band. Therefore, a novel DMF with a offset-feed bended coupling structure and a stepped-impedance dual- mode resonator is proposed for coupling enhancement and spurious response suppression. Based on the analysis of the change of spur frequencies and the current distribution of spur resonant modes, all spurs near passband of the cascaded DMF can be fully suppressed by optimizing the structure parameters of parasite resonators, which bene- fits from the inherent well-controlled transmission zeros. Experimental results show that the proposed DMF ex- hibits lower insertion loss ,much sharper rate of cutoff and wider spur-free stop band compared with conventional DMF. This design is applicable for spur suppression in wideband communication. 展开更多
关键词 dual-mode bandpass filter coupling structure spur suppression stepped-impedance resonator trans- mission zero
在线阅读 下载PDF
TARGET INFORMATION DIFFERENTIATING TECHNOLOGY IN INFRARED-RADAR DUAL-MODE GUIDANCE SYSTEM
4
作者 杨俊鹏 祝小平 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第3期245-249,共5页
An improved target tracking information differentiating system using the neural network to substitute for fuzzy rules is presented for the infrared-radar dual-mode guidance system. Since the neural network training ba... An improved target tracking information differentiating system using the neural network to substitute for fuzzy rules is presented for the infrared-radar dual-mode guidance system. Since the neural network training based on the expert knowledge database is conducted off-line, the benefits for developing real-time tracking capabilities can be obtained. The network outputs the confidence degree denoted by the weight value of target information in the data fusion center according to two input variables of the measurement noise covariance and the tracking filter covariance. Simulation results show that the improved system can differentiate the target tracking information from the seeker fast and accurately. 展开更多
关键词 dual-mode guidance system confidence degree information differentiating
在线阅读 下载PDF
Green and Near-Infrared Dual-Mode Afterglow of Carbon Dots and Their Applications for Confidential Information Readout 被引量:11
5
作者 Yuci Wang Kai Jiang +4 位作者 Jiaren Du Licheng Zheng Yike Li Zhongjun Li Hengwei Lin 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第12期148-162,共15页
Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a fac... Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots(CDs) through in situ embedding o-CDs(being prepared from o-phenylenediamine) into cyanuric acid(CA) matrix(named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) of o-CDs,respectively. In addition,the formation of covalent bonds between o-CDs and CA,and the presence of multiple fixation and rigid e ects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA,it is completely covered by the green TADF during directly observing. The NIR RTP signal,however,can be readily captured if an optical filter(cut-o wavelength of 600 nm) being used. By utilizing these unique features,the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally,the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances. 展开更多
关键词 Carbon dots dual-mode afterglow Room temperature phosphorescence Thermal activated delayed fluorescence Information security
在线阅读 下载PDF
Facile Approach to Synthesize Gold Nanorod@Polyacrylic Acid/Calcium Phosphate Yolk–Shell Nanoparticles for Dual-Mode Imaging and pH/NIR-Responsive Drug Delivery 被引量:4
6
作者 Guilan Li Yidan Chen +5 位作者 Lingyu Zhang Manjie Zhang Shengnan Li Lu Li Tingting Wang Chungang Wang 《Nano-Micro Letters》 SCIE EI CAS 2018年第1期63-73,共11页
A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca ... A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca P yolk–shell NPs possess ultrahigh doxorubicin(DOX) loading capability(1 mg DOX/mg NPs), superior photothermal conversion property(26%)and p H/near-infrared(NIR) dual-responsive drug delivery performance. The released DOX continuously increased due to the damage of the Ca P shell at low p H values. When the DOX-loaded Au NR@PAA/Ca P yolk–shell NPs wereexposed to NIR irradiation, a burst-like drug release occurs owing to the heat produced by the Au NRs. Furthermore,Au NR@PAA/Ca P yolk–shell NPs are successfully employed for synergic dual-mode X-ray computed tomography/photoacoustic imaging and chemo-photothermal cancer therapy. Therefore, this work brings new insights for the synthesis of multifunctional nanomaterials and extends theranostic applications. 展开更多
关键词 Yolk–shell structure Calcium phosphate dual-mode imaging Photothermal therapy Drug delivery
在线阅读 下载PDF
A single dual-mode gas sensor for early safety warning of Li-ion batteries:Micro-scale Li dendrite and electrolyte leakage
7
作者 Wenjun Yan Zhishen Jin +4 位作者 Zhengyang Lin Shiyu Zhou Yonghai Du Yulong Chen Houpan Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第11期291-296,共6页
Li dendrites and electrolyte leakage are common causes of Li-ion battery failure.H_(2),generated by Li dendrites,and electrolyte vapors have been regarded as gas markers of the early safety warning of Li-ion batteries... Li dendrites and electrolyte leakage are common causes of Li-ion battery failure.H_(2),generated by Li dendrites,and electrolyte vapors have been regarded as gas markers of the early safety warning of Li-ion batteries.SnO_(2)-based gas sensors,widely used for a variety of applications,are promising for the early safety detection of Li-ion batteries,which are necessary and urgently required for the development of Li-ion battery systems.However,the traditional SnO_(2)sensor,with a single signal,cannot demonstrate intelligent multi-gas recognition.Here,a single dual-mode(direct and alternating current modes)SnO_(2)sensor demonstrates clear discrimination of electrolyte vapors and H_(2),released in different states of Li-ion batteries,together with principal component analysis(PCA)analysis.This work provides insight into the intelligent technology of single gas sensors. 展开更多
关键词 gas sensors single dual-mode multivariable sensors Li-batteries early safety warning
在线阅读 下载PDF
ZTE Dual-mode Mobiles Highlighted at ITU HK
8
《ZTE Communications》 2006年第4期11-11,共1页
关键词 MODE ZTE dual-mode Mobiles Highlighted at ITU HK SCDMA ITU HK
在线阅读 下载PDF
Dual-Mode Terahertz Extended Interaction Oscillator Driven by a Pseudospark-Sourced Sheet Electron Beam
9
作者 Jie Xie Xue-Song Yuan +7 位作者 Liang Zhang Adrian W.Cross Hua-Bi Yin Qing-Yun Chen Tong-Bin Yang Xiao-Tao Xu Yang Yan Lin Meng 《Journal of Electronic Science and Technology》 CAS CSCD 2021年第3期243-254,共12页
A terahertz dual-mode extended interaction oscillator (EIO) driven by a pseudospark-sourced sheet electron beam (SEB) was presented.The major advantages of the newly developed circuit include 1) high-density SEB inter... A terahertz dual-mode extended interaction oscillator (EIO) driven by a pseudospark-sourced sheet electron beam (SEB) was presented.The major advantages of the newly developed circuit include 1) high-density SEB interacting with the TM_(11) and TM_(31) modes,respectively,and 2) high output power of over 1 kW at the subterahertz frequency range.Two different types of 2π modes and their output characteristics were studied,and the circuit was optimized to ensure efficient outputs of two standing-wave modes.The three-dimensional (3D) particle-in-cell (PIC) simulation predicts the maximum output power of 1.3 kW with the 3-dB bandwidth of ~0.5 GHz at 303 GHz when operating at the TM_(11)mode,and 3.18 kW with the 3-dB bandwidth of ~0.85 GHz at 364 GHz when operating at the TM_(31)mode. 展开更多
关键词 dual-mode operation extended interaction oscillator(EIO) high-power radiation pseudospark-sourced(PS)electron beam sheet electron beam(SEB) TERAHERTZ
在线阅读 下载PDF
Numerical simulation on magnetohydrodynamic power generation channel of scramjet
10
作者 LING Wenhui WU Shaoxun +2 位作者 ZHANG Yining LIU Chenyuan MENG Hao 《推进技术》 EI CAS CSCD 北大核心 2024年第11期255-268,共14页
The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distanc... The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distance flight airframe power.In this paper,a computational model of the scramjet magnetohydrody⁃namic channel is developed and verified by using the commercial software Fluent.It is found that when the mag⁃netic induction intensity is 1,2,3,4 T,the power generation efficiency is 22.5%,22.3%,22.0%,21.5%,and decreases with the increase of the magnetic induction intensity,and the enthalpy extraction rate is 0.026%,0.1%,0.21%,0.34%,and increases with the increase of the magnetic induction intensity.The deceleration ef⁃fect of electromagnetic action on the airflow in the power channel increases with the increase of magnetic induc⁃tion intensity.The stronger the magnetic field intensity,the more obvious the decreasing effect of fluid Mach num⁃ber in the channel.The power generation efficiency decreases as the magnetic induction intensity increases and the enthalpy extraction rate is reversed.As the local currents gathering at inlet and outlet of the power generation area,total temperature and enthalpy along the flow direction do not vary linearly,and there are maximum and minimum values at inlet and outlet.Increasing the number of electrodes can effectively regulate the percentage of Joule heat dissipation,which can improve the power generation efficiency. 展开更多
关键词 scramjet MAGNETOHYDRODYNAMICS Power generation channel Ionized seeds Numerical simulation
在线阅读 下载PDF
A Dual-Mode Step-up DC/DC Converter IC with Current-Limiting and EMI Reduction Techniques
11
作者 Wan-Rone Liou Ping-Hsing Chen +2 位作者 Marynelle L. Z. Rosales Yeh Chun-Ting Kuo Mei-Ling Yeh 《Journal of Electronic Science and Technology of China》 2008年第3期279-283,共5页
This paper presents a novel dual-mode step-up (boost) DC/DC converter. Pulse-frequency modulation (PFM) is used to improve the efficiency at light load. This converter can operate between pulse-width modulation (... This paper presents a novel dual-mode step-up (boost) DC/DC converter. Pulse-frequency modulation (PFM) is used to improve the efficiency at light load. This converter can operate between pulse-width modulation (PWM) and pulse-frequency modulation. The converter will operate in PFM mode at light load and in PWM mode at heavy load. The maximum conversion efficiency of this converter is 96%. The conversion efficiency is greatly improved when load current is below 100 mA. Additionally, a soft-start circuit and a variable-sawtooth frequency circuit are proposed in this paper. The former is used to avoid the large switching current at the start up of the converter and the latter is utilized to reduce the EMI of the converter. 展开更多
关键词 Boost converter dual-mode converter integrated power management pulse-frequency modulation (PFM) pulse-width modulation (PWM)
在线阅读 下载PDF
Scramjet尾喷管几何调节方案的计算与实验研究 被引量:5
12
作者 葛建辉 徐惊雷 +1 位作者 庞丽娜 莫建伟 《推进技术》 EI CAS CSCD 北大核心 2013年第9期1158-1164,共7页
高超声速飞行器飞行接力点和巡航结束点尾喷管冷、热态俯仰力矩差较大,给飞行器的飞行姿态控制造成严重影响。为了减小喷管冷、热态俯仰力矩差,提出了在喷管上膨胀面末端增加移动板进行调节的方案,并进行了详细的三维数值模拟和相应的... 高超声速飞行器飞行接力点和巡航结束点尾喷管冷、热态俯仰力矩差较大,给飞行器的飞行姿态控制造成严重影响。为了减小喷管冷、热态俯仰力矩差,提出了在喷管上膨胀面末端增加移动板进行调节的方案,并进行了详细的三维数值模拟和相应的风洞缩比冷流实验研究。计算结果表明,Ma=4.5时,调节移动板伸出400mm,喷管冷、热态力矩差最大减小21.74%,推力系数损失1.64%;Ma=6.5时,调节移动板喷管冷、热态力矩差可降低77.59%,而推力系数只减小1.35%,调节收益非常明显。最后通过将喷管各调节状态下的冷流缩比实验壁面压力数据与计算结果的对比,证明了该调节方案的计算方法及其结果是可靠的,同时得出该调节方案可以有效地降低冷、热态力矩差的结论。 展开更多
关键词 超燃冲压发动机 尾喷管 几何调节 俯仰力矩差 数值模拟 实验研究
在线阅读 下载PDF
Scramjet燃烧室流场的三维并行数值模拟及试验比较 被引量:1
13
作者 郑忠华 乐嘉陵 《流体力学实验与测量》 CSCD 北大核心 2002年第2期9-15,共7页
作者采用时间相关法,通过有限体积离散,运用带化学反应的全N S方程,在神州巨型机上,针对试验模型,对油气比Φ=0.0和0.35的喷氢Scramjet燃烧室流场进行了三维并行数值模拟,得到了流场的精细结构。并行模拟所得壁面压力分布与试验所测得... 作者采用时间相关法,通过有限体积离散,运用带化学反应的全N S方程,在神州巨型机上,针对试验模型,对油气比Φ=0.0和0.35的喷氢Scramjet燃烧室流场进行了三维并行数值模拟,得到了流场的精细结构。并行模拟所得壁面压力分布与试验所测得的壁面压力分布吻合较好。 展开更多
关键词 试验比较 有限体积法 并行计算 scramjet燃烧室 流场 数值模拟
在线阅读 下载PDF
全几何约束下的非对称喷管伴随优化设计研究
14
作者 付珂欣 徐惊雷 +1 位作者 刘增旭 俞凯凯 《推进技术》 北大核心 2025年第3期51-60,共10页
为了实现高超声速排气系统与飞行器后体一体化,非对称喷管需要在有限的空间内、严格的几何约束下完成对高温高压气体的高效膨胀,并达到高性能的需求。然而在实际非对称喷管设计中,往往面临着强几何约束、设计变量规模较大等问题,造成现... 为了实现高超声速排气系统与飞行器后体一体化,非对称喷管需要在有限的空间内、严格的几何约束下完成对高温高压气体的高效膨胀,并达到高性能的需求。然而在实际非对称喷管设计中,往往面临着强几何约束、设计变量规模较大等问题,造成现有方法难以完全实现非对称喷管的高效设计。为此,本文采用伴随优化方法针对非对称喷管开展气动设计,分别展开了全几何约束下的推力最优和升力最优两类设计研究。在推力最优设计结果中可得到,优化后的非对称喷管内部压力场分布显著改变,从而使得推力系数相对于初始直壁面喷管增加了5.966%。在升力最优设计中,喷管内下壁面会产生一道弱激波,该道弱激波在喷管上壁面的反射显著提升了上壁面局部的压力,进而使得升力相对于直壁面喷管增加了44.921%。从两类优化结果中可以看到相比初始构型,伴随优化方法可以在实现全几何约束下的非对称喷管设计同时,能够有效保持喷管所需的推力及升力性能。 展开更多
关键词 超燃冲压发动机 非对称喷管 气动优化 离散伴随 几何约束
在线阅读 下载PDF
模拟Scramjet隔离段实际入口的直连试验设备设计试验验证 被引量:1
15
作者 唐兰 徐惊雷 +2 位作者 俞凯凯 曹学斌 满延进 《推进技术》 EI CAS CSCD 北大核心 2016年第10期1970-1976,共7页
为了模拟进气道喉道非均匀流场对超燃冲压发动机隔离段流动特性的影响,针对典型超燃冲压发动机隔离段入口流场的马赫数分布要求,设计了隔离段直连试验设备。该设备整个通道采用扩张构型,在附面层发展段的下壁面采用加圆形凸台的方法加... 为了模拟进气道喉道非均匀流场对超燃冲压发动机隔离段流动特性的影响,针对典型超燃冲压发动机隔离段入口流场的马赫数分布要求,设计了隔离段直连试验设备。该设备整个通道采用扩张构型,在附面层发展段的下壁面采用加圆形凸台的方法加速附面层发展,并针对该设备进行了数值模拟和冷流试验。结果表明,该直连试验设备不仅能准确模拟隔离段实际入口流场(即入射激波和非对称附面层),模拟的主流区马赫数与目标值差值在0.02以内,还解决了传统的直连试验设备存在的启动问题。试验与数值模拟结果吻合较好,验证了该直连试验设备设计方法的可行性。 展开更多
关键词 超燃冲压发动机 隔离段直连试验 附面层 非均匀 激波
在线阅读 下载PDF
MHD-Arc-Scramjet联合循环发动机的性能分析 被引量:1
16
作者 唐井峰 鲍文 于达仁 《推进技术》 EI CAS CSCD 北大核心 2008年第4期465-470,共6页
以MHD-Arc-Scramjet联合循环发动机为对象开展性能分析,探讨了能量旁路系统对发动机性能的影响,给出了MHD-Arc-Scramjet联合循环发动机相对于传统冲压发动机的单位推力差异。结果表明:电子束电离消耗的能量,能量旁路比例,电弧注入... 以MHD-Arc-Scramjet联合循环发动机为对象开展性能分析,探讨了能量旁路系统对发动机性能的影响,给出了MHD-Arc-Scramjet联合循环发动机相对于传统冲压发动机的单位推力差异。结果表明:电子束电离消耗的能量,能量旁路比例,电弧注入过程的最高温度以及进气道的压缩程度是能量旁路系统中影响发动机单位推力的主要因素;在这些参数的取值范围内合理取值,并兼顾材料和技术实现等约束,性能分析表明:在来流速度2800-4000m/s范围内MHD-Arc-Scramjet联合循环发动机相对传统冲压发动机具有明显的单位推力优势。 展开更多
关键词 冲压发动机 能量旁路系统 MHD-Arc-scramjet联合循环发动机+ 性能分析
在线阅读 下载PDF
Scramjet整机流场的非结构网格并行数值模拟 被引量:3
17
作者 王兰 吴颖川 乐嘉陵 《推进技术》 EI CAS CSCD 北大核心 2009年第1期34-40,共7页
为了得到某支板喷氢超燃冲压发动机内流场的细节,采用非结构网格CFD隐式解算器,耦合求解Na-vire-Stokes方程、组分连续方程和M enter的k-ω应力剪切传输(SST)湍流模型,对整机模型的冷流和三个当量油气比的湍流反应流进行了三维并行模... 为了得到某支板喷氢超燃冲压发动机内流场的细节,采用非结构网格CFD隐式解算器,耦合求解Na-vire-Stokes方程、组分连续方程和M enter的k-ω应力剪切传输(SST)湍流模型,对整机模型的冷流和三个当量油气比的湍流反应流进行了三维并行模拟。给出了流线和水的分布云图,分析了支板附近旋涡和推进流道一维质量加权平均的马赫数、静温、组分质量分数及燃烧效率等参数随当量油气比的变化,并将壁面压力和实验值进行了比较,吻合较好。除=0.8在支板附近出现了小范围亚声速外,其余状态整个内流道超声速占主流。 展开更多
关键词 超燃发动机 非结构网格 支板 湍流反应流 并行计算 旋涡
在线阅读 下载PDF
高马赫气流中双排横向喷注燃料增混方法数值研究
18
作者 周越寰 张旭 +3 位作者 黄庭隆 于德海 岳连捷 孙波 《推进技术》 北大核心 2025年第3期173-182,共10页
针对高马赫数燃烧室的掺混难题,本文数值研究了入口马赫数4.08条件下流向孔间距、当量比和喷注总压对双排氢燃料喷注掺混规律的影响。相比以往研究仅发现极近流向孔间距有利于近场掺混,本文进一步发现25~70倍孔径的较远流向孔间距能够... 针对高马赫数燃烧室的掺混难题,本文数值研究了入口马赫数4.08条件下流向孔间距、当量比和喷注总压对双排氢燃料喷注掺混规律的影响。相比以往研究仅发现极近流向孔间距有利于近场掺混,本文进一步发现25~70倍孔径的较远流向孔间距能够改善远场掺混,且最佳间距与当量比和喷注总压有关,其对应掺混增益范围为1.16~1.25。给定当量比和孔间距条件下,合理设置喷注总压能进一步改善远场掺混,使掺混增益达1.29。通过剖析流场结构,揭示了双排喷注增强掺混的两种机制,分别与弓形激波等因素降低上游喷注尾迹区的静压和动压相关。其一,较近流向孔间距时,上游喷注尾迹区低静压意味着下游喷注反压比提高,促进下游喷注诱导流动分离,有利于喷孔近场掺混。其二,较远流向孔间距时,上游喷注尾迹区低动压意味着下游喷注动量比提高,能改善下游喷注射流穿透深度,有利于下游远场掺混。实际掺混过程中,总掺混增益是两种机制耦合作用的结果,最佳间距取决于当量比和喷注压力。 展开更多
关键词 超燃冲压发动机 横向射流 双排喷注 增混方法 远场掺混
在线阅读 下载PDF
SCRAMJET INLET MULTI-OBJECTIVE OPTIMIZATION BASED ON RESPONSE SURFACE METHODOLOGY 被引量:1
19
作者 李健 谷良贤 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第3期205-210,共6页
The uniform design and response surface methodology (RSM) are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selec... The uniform design and response surface methodology (RSM) are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics (CFD). Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency. 展开更多
关键词 scramjet inlet response surface methodology oblique shock multi-objective optimization
在线阅读 下载PDF
基于丙酮示踪技术的超燃冲压发动机高温流场可视化研究
20
作者 王林森 涂晓波 +3 位作者 周全 车庆丰 王宇航 陈爽 《实验流体力学》 北大核心 2025年第1期87-94,共8页
为进一步研究超燃冲压发动机接近实际工作状态时,不同支板结构对燃料/空气掺混效果的影响,本文在课题组前期工作的基础上,改进了部分试验系统,进行了热态试验环境下的丙酮平面激光诱导荧光(PLIF)测量和H2点火燃烧条件下的OH-PLIF测量,... 为进一步研究超燃冲压发动机接近实际工作状态时,不同支板结构对燃料/空气掺混效果的影响,本文在课题组前期工作的基础上,改进了部分试验系统,进行了热态试验环境下的丙酮平面激光诱导荧光(PLIF)测量和H2点火燃烧条件下的OH-PLIF测量,得到了多种工况条件下,多个横截面位置的丙酮PLIF和OH-PLIF荧光图像。结果表明:在热态试验环境下,采用4种支板时的丙酮PLIF信号比冷态试验结果整体上弱了许多,但采用EL1支板时,燃料/空气的掺混效果与冷态试验结果保持一致(仍为最优);在H2点火燃烧条件下,从OH的生成数量和扩散区域可以看出,EL1支板对燃烧效率的提升作用更好,这也从侧面证明了EL1支板在4种支板中效果最优。 展开更多
关键词 丙酮示踪 超燃冲压发动机 掺混效果 平面激光诱导荧光 流场结构
在线阅读 下载PDF
上一页 1 2 25 下一页 到第
使用帮助 返回顶部