Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 1009

会议视频 9

年份

2023 70

2022 85

2021 69

2020 72

2019 51

2018 43

2017 46

2016 41

2015 53

2014 44

2013 40

2012 42

2011 36

2010 47

2009 48

2008 39

2007 37

2006 27

2005 26

2004 22

展开︾

关键词

数学模型 13

模型试验 9

数值模拟 8

模型 7

不确定性 5

COVID-19 4

GM(1 3

计算机模拟 3

1)模型 2

DX桩 2

D区 2

Preissmann格式 2

SARS 2

TRIZ 2

Weibull分布 2

k-ε模型 2

临震信号 2

云模型 2

人员疏散 2

展开︾

检索范围：

排序：展示方式：

Theoretical study on flow and radiation in tubular solar photocatalytic reactor

《能源前沿（英文）》 2021年第15卷第3期页码 687-699 doi: 10.1007/s11708-021-0773-9

摘要： In this paper, based on the mixture flow model, an optimized six-flux model is first established and applied to the tubular solar photocatalytic reactor. Parameters influencing photocatalyst distribution and radiation distribution at the reactor outlet, viz. catalyst concentration and circulation speed, are also analyzed. It is found that, at the outlet of the reactor, the optimized six-flux model has better performances (the energy increase by 1900% and 284%, respectively) with a higher catalyst concentration (triple) and a lower speed (one third).

关键词： photocatalytic hydrogen photoreactor nume- rical simulation solar energy flow model radiation model

HTML PDF 收藏

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propanefires in open space based on weighted multi-point source model

Jie JI, Junrui DUAN, Huaxian WAN

《能源前沿（英文）》 2022年第16卷第6期页码 1017-1026 doi: 10.1007/s11708-020-0716-x

摘要： The interaction of multiple fires may lead to a higher flame height and more intense radiation flux than a single fire, which increases the possibility of flame spread and risks to the surroundings. Experiments were conducted using three burners with identical heat release rates (HRRs) and propane as the fuel at various spacings. The results show that flames change from non-merging to merging as the spacing decreases, which result in a complex evolution of flame height and merging point height. To facilitate the analysis, a novel merging criterion based on the dimensionless spacing / was proposed. For non-merging flames ( / >0.368), the flame height is almost identical to a single fire; for merging flames ( / ≤0.368), based on the relationship between thermal buoyancy and thrust (the pressure difference between the inside and outside of the flame), a quantitative analysis of the flame height, merging point height, and air entrainment was formed, and the calculated merging flame heights show a good agreement with the measured experimental values. Moreover, the multi-point source model was further improved, and radiation fraction of propane was calculated. The data obtained in this study would play an important role in calculating the external radiation of propane fire.

关键词： flame interaction air entrainment flame height multi-point source model thermal radiation

HTML PDF 收藏

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectralmodel

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2011年第5卷第2期页码 149-158 doi: 10.1007/s11708-010-0124-8

摘要： The nongray behavior of combustion products plays an important role in various areas of engineering. Based on the statistical narrow-band (SNB) spectral model with an exponential-tailed inverse intensity distribution and the ray-tracing method, a comprehensive investigation of the influence of soot on nongray radiation from mixtures containing H O/N +soot, CO /N +soot, or H O/CO /N +soot was conducted in this paper. In combustion applications, radiation transfer is significantly enhanced by soot due to its spectrally continuous emission. The effect of soot volume fraction up to 1×10 on the source term, the narrow-band radiation intensities along a line-of-sight, and the net wall heat fluxes were investigated for a wide range of temperature. The effect of soot was significant and became increasingly drastic with the increase of soot loading.

关键词： soot combustion SNB model nongray radiation

HTML PDF 收藏

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

《能源前沿（英文）》 2020年第14卷第2期页码 383-399 doi: 10.1007/s11708-017-0505-3

摘要： Prediction of solar radiation has drawn increasing attention in the recent years. This is because of the lack of solar radiation measurement stations. In the present work, 14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters: extraterrestrial solar irradiance ( ), duration sunshine ( ) and daylight hours ( ). Since it has been observed that each model is adequate for some months of the year, one model cannot be used for the prediction of the whole year. Therefore, a smart hybrid system is proposed which selects, based on the intelligent rules, the most suitable prediction model of the 14 models listed in this study. For the test and evaluation of the proposed models, Tamanrasset city, which is located in the south of Algeria, is selected for this study. The meteorological data sets of five years (2000–2004) have been collected from the Algerian National Office of Meteorology (NOM), and two spatial databases. The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation, which offers an excellent measuring accuracy of values ranging from 93% to 97% in this location.

关键词： global solar radiation statistical indicator hybrid model spatial database correlation coefficients

HTML PDF 收藏

大空间内着火位置对火灾增长的影响

石龙,张瑞芳, 谢启源,付丽华

《中国工程科学》 2008年第10卷第11期页码 37-42

摘要：

以大空间展厅为例，利用火源辐射模型和烟气辐射模型并结合CFAST6.0区域模拟软件的计算结果，对比分析了大空间内不同着火位置下火灾增长的情况。研究结果表明仅考虑火源热辐射的情况下，展厅内着火位置越处于左右中间对称处，其火灾增长越快，热释放速率峰值也越大，达到热释放速率峰值的时间和火灾的持续时间越短，处于展厅中心位置时所有值达峰值。对火源热辐射和烟气辐射综合考虑时，到达热释放速率峰值时间与火灾持续时间的规律同仅考虑火源辐射模型时一致，但热释放速率峰值均有不同程度的提高。

关键词：火灾增长大空间着火位置火灾场景设置火源辐射模型烟气辐射模型

HTML PDF 收藏

Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo

O. S. OHUNAKIN, M. S. ADARAMOLA, O. M. OYEWOLA, R. O. FAGBENLE

《能源前沿（英文）》 2013年第7卷第2期页码 214-222 doi: 10.1007/s11708-013-0241-2

摘要： In this study, the global solar radiation on horizontal surface in Osogbo, Osun state, Nigeria was analyzed using 11-year data (1997–2007). Correlations using linear and quadratic expressions were developed to relate the global solar radiation on horizontal surface based on relative sunshine hours and temperature measurements for evaluating the monthly average daily global solar radiation. The calculated monthly clearness index values indicate that the prevailing weather condition in Osogbo is heavily overcast. All the developed quadratic correlations gave better correlation coefficients (0.834, 0.872 and 0.823 respectively) than the linear models. However, the Hargreaves and Samani related based quadratic model gave the best among the three developed quadratic expressions and is therefore suggested for estimating the monthly global radiation in this site and its surroundings.

关键词： global solar radiation Hargreaves model sunshine hour ambient temperatures Osogbo

HTML PDF 收藏

Entropy production analysis of swirling diffusion combustion processes

Deodat MAKHANLALL, Linhua LIU,

《能源前沿（英文）》 2010年第4卷第3期页码 326-332 doi: 10.1007/s11708-009-0058-1

摘要： A critical factor in the design of combustion systems for optimum fuel economy and emission performance lies in adequately predicting thermodynamic irreversibilities associated with transport and chemical processes. The objective of this study is to map these irreversibilities in terms of entropy production for methane combustion. The numerical solution of the combustion process is conducted with the help of a Fluent 6.1.22 computer code, and the volumetric entropy production rate due to chemical reaction, viscous dissipation, and mass and heat transfer are calculated as post-processed quantities with the computed data of the reaction rates, fluid velocity, temperature and radiative intensity. This paper shows that radiative heat transfer, which is an important source of entropy production, cannot be omitted for combustion systems. The study is extended by conducting a parametric investigation to include the effects of wall emissivity, optical thickness, swirl number, and Boltzmann number on entropy production. Global entropy production rates decrease with the increase in swirl velocity, wall emissivity and optical thickness. Introducing swirling air into the combustion system and operations with the appropriate Boltzmann number reduces the irreversibility affected regions and improves energy utilization efficiency.

关键词： entropy-based design radiation transfer swirl magnussen combustion-model

HTML PDF 收藏

Particle therapy for cancers: a new weapon in radiation therapy

null

《医学前沿（英文）》 2012年第6卷第2期页码 165-172 doi: 10.1007/s11684-012-0196-4

摘要：

Particle irradiation started to draw attention in the past decade and has now become a hotspot in the radiation oncology community. This article reviews the most advanced developments in particle irradiation, focusing on the characteristics of proton and carbon ions in radiation physics and radiobiology. The Bragg peak of physical dose distribution causes proton and carbon beams to optimally meet the requirement for cancer irradiation because the Bragg peak permits the accurate concentration of the dose on the tumor, thus sparing the adjacent normal tissues. Moreover, carbon ion has more radiobiological benefits than photon and proton beams. These benefits include stronger sterilization effects on intrinsic radio-resistant tumors and more effective killing of hypoxic, G₀, and S phase cells. Compared with the most advanced radiation techniques using photon, such as three-dimensional conformal radiation therapy and intensity-modulated radiation therapy, proton therapy has yielded more promising outcomes in local control and survival for head and neck cancers, prostate carcinoma, and pediatric cancers. Carbon therapy in Japan showed even more promising results than proton therapy. The local controls and overall survivals were as good as that treated by surgery in early stages of non-small cell lung cancer, hepatocellular carcinoma, prostate carcinoma, and head and neck cancers, especially for such highly resistant tumors as melanoma. The non-invasive nature of particle therapy affords more patients with chances to receive and benefit from treatment. Particle therapy is gradually getting attention from the oncology community. However, the cost of particle therapy facilities has limited the worldwide use of this technology.

关键词： radiation therapy particle therapy proton carbon cancer

HTML PDF 收藏

Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

《能源前沿（英文）》 2017年第11卷第4期页码 480-492 doi: 10.1007/s11708-017-0506-2

摘要： This paper investigated radiation heat transfer and temperature distributions of solar thermochemical reactor for syngas production using the finite volume discrete ordinate method (fvDOM) and P1 approximation for radiation heat transfer. Different parameters including absorptivity, emissivity, reflection based radiation scattering, and carrier gas flow inlet velocity that would greatly affect the reactor thermal performance were sufficiently investigated. The fvDOM approximation was used to obtain the radiation intensity distribution along the reactor. The drop in the temperature resulted from the radiation scattering was further investigated using the P1 approximation. The results indicated that the reactor temperature difference between the P1 approximation and the fvDOM radiation model was very close under different operating conditions. However, a big temperature difference which increased with an increase in the radiation emissivity due to the thermal non-equilibrium was observed in the radiation inlet region. It was found that the incident radiation flux distribution had a strong impact on the temperature distribution throughout the reactor. This paper revealed that the temperature drop caused by the boundary radiation heat loss should not be neglected for the thermal performance analysis of solar thermochemical reactor.

关键词： solar thermochemical reactor incident radiation flux temperature distribution radiation absorptivity radiation emissivity thermal performance analysis

HTML PDF 收藏

Security of solar radiation management geoengineering

Andrew LOCKLEY

《工程管理前沿（英文）》 2019年第6卷第1期页码 102-116 doi: 10.1007/s42524-019-0008-5

摘要：

Solar Radiation Management (SRM) geoengineering is a proposed response to anthropogenic global warming (AGW) (National Academy of Sciences, 2015). There may be profound – even violent – disagreement on preferred temperature. SRM disruption risks dangerous temperature rise (termination shock). Concentrating on aircraft-delivered Stratospheric Aerosol Injection (SAI), we appraise threats to SRM and defense methodologies. Civil protest and minor cyberattacks are almost inevitable but are manageable (unless state-sponsored). Overt military attacks are more disruptive, but unlikely – although superpowers’ symbolic overt attacks may deter SRM. Unattributable attacks are likely, and mandate use of widely-available weapons. Risks from unsophisticated weapons are therefore higher. An extended supply chain is more vulnerable than a secure airbase – necessitating supply-chain hardening. Recommendations to improve SRM resilience include heterogeneous operations from diverse, secure, well-stocked bases (possibly ocean islands or aircraft carriers); and avoidance of single-point-of-failure risks (e.g. balloons). A distributed, civilian-operated system offers an alternative strategy. A multilateral, consensual SRM approach reduces likely attack triggers.

关键词： security geoengineering solar radiation ma-nagement SRM

HTML PDF 收藏

Distributed governance of Solar Radiation Management geoengineering: A possible solution to SRM’s “free-driver

Andrew LOCKLEY

《工程管理前沿（英文）》 2019年第6卷第4期页码 551-556 doi: 10.1007/s42524-019-0055-y

摘要： Geoengineering (deliberate climate modification) is a possible way to limit Anthropogenic Global Warming (AGW) (Shepherd, 2009; National Research Council, 2015). Solar Radiation Management geoengineering (SRM) offers relatively inexpensive, rapid temperature control. However, this low cost leads to a risk of controversial unilateral intervention—the “free-driver” problem (Weitzman, 2015). Consequently, this creates a risk of counter-geoengineering (deliberate warming) (Parker et al., 2018), resulting in governance challenges (Svoboda, 2017) akin to an arms race. Free-driver deployment scenarios previously considered include the rogue state, Greenfinger (Bodansky, 2013), or power blocs (Ricke et al., 2013), implying disagreement and conflict. We propose a novel distributed governance model of consensually-constrained unilateralism: Countries’ authority is limited to each state’s fraction of the maximum realistic intervention (e.g., pre-industrial temperature). We suggest a division of authority based on historical emissions (Rocha et al., 2015)—noting alternatives (e.g., population). To aid understanding, we offer an analogue: An over-heated train carriage, with passenger-controlled windows. We subsequently discuss the likely complexities, notably Coasian side-payments. Finally, we suggest further research: Algebraic, bot and human modeling; and observational studies.

关键词： geoengineering Solar Radiation Management governance decentralised

HTML PDF 收藏

动态热过程分析用建筑几何模型的构建

丁力行,何立群,陈祖铭,刘仙萍,季杰

《中国工程科学》 2010年第12卷第8期页码 88-93

摘要：

建筑墙体表面的太阳直射辐射投影及辐射强度随时间发生很大变化，该变化在已有的动态热过程算法框架内很难直接计算。根据建筑传热模型特点和计算机图形学原理，构建了动态热过程的建筑几何模型，该模型将建筑空间抽象为由矢量平面围成的空间区域的集合；提出了建筑几何模型的核心计算方法，即三维空间内直线与表面的矢量运算。该建筑几何模型能解决建筑动态热过程中直接计算建筑墙体表面之间的太阳直射辐射换热和太阳直射辐射投影等问题，并对空气流通、楼房之间的相互遮阳和光污染等问题的研究也具有实际意义。

关键词：建筑热过程几何模型太阳辐射

HTML PDF 收藏

Ambient photolysis frequency of NO

Qi Zou,Keding Lu,Yusheng Wu,Yudong Yang,Zhuofei Du,Min Hu

《环境科学与工程前沿（英文）》 2016年第10卷第6期 doi: 10.1007/s11783-016-0885-3

摘要： • Chemical actinometer (CA) was built for NO photolysis frequency, j(NO ), analysis. • CA data (10% accuracy) were compared with spectroradiometer (SR) data. • Long-term j(NO ) measurement was validated by comparison of CA and SR. • Dis-benefit of aerosol on j(NO ) due toparticulate matter (PM ) control on O . The photolysis frequency of NO , j(NO ), is an important analytical parameter in the study of tropospheric chemistry. A chemical actinometer (CA) was built to measure the ambient j(NO ) based on a high precision NO instrument with 1 min time resolution. Parallel measurements of the ambient j(NO ) by using the CA and a commercial spectroradiometer (SR) were conducted at a typical urban site (Peking University Urban Environmental Monitoring Station) in Beijing. In general, good agreement was achieved between the CA and SR data with a high linear correlation coefficient ( = 0.977) and a regression slope of 1.12. The regression offset was negligible compared to the measured signal level. The j(NO ) data were calculated using the tropospheric ultraviolet visible radiation (TUV) model, which was constrained to observe aerosol optical properties. The calculated j(NO ) was intermediate between the results obtained with CA and SR, demonstrating the consistency of all the parameters observed at this site. The good agreement between the CA and SR data, and the consistency with the TUV model results, demonstrate the good performance of the installed SR instrument. Since a drift of the SR sensitivity is expected by the manufacturer, we propose a regular check of the data acquired via SR against those obtained by CA for long-term delivery of a high quality series of j(NO ) data. Establishing such a time series will be invaluable for analyzing the long-term atmospheric oxidation capacity trends as well as O pollution for urban Beijing.

关键词： Photolysis frequency of nitrogen dioxide Chemical actinometer Spectroradiometer Tropospheric ultraviolet visible radiation model

HTML PDF 收藏

Design and analysis of Salisbury screens and Jaumann absorbers for solar radiation absorption

Xing FANG, C. Y. ZHAO, Hua BAO

《能源前沿（英文）》 2018年第12卷第1期页码 158-168 doi: 10.1007/s11708-018-0542-6

摘要： Two types of resonance absorbers, i.e., Salisbury screens and Jaumann absorbers are systematically investigated in solar radiation absorption. Salisbury screen is a metal-dielectric-metal structure which overcomes the drawback of bulky thickness for solar spectrum. Such structures have a good spectral selective absorption property, which is also insensitive to incident angles and polarizations. To further broaden absorption bandwidth, more metal and dielectric films are taken in the structure to form Jaumann absorbers. To design optimized structural parameters, the admittance matching equations have been derived in this paper to give good initial structures, which are valuable for the following optimization. Moreover, the analysis of admittance loci has been conducted to directly show the effect of each layer on the spectral absorptivity, and then the effect of thin films is well understood. Since the fabrication of these layered absorbers is much easier than that of other nanostructured absorbers, Salisbury screen and Jaumann absorbers have a great potential in large-area applications.

关键词： thin films admittance loci solar absorber

HTML PDF 收藏

Gain-enhanced reconfigurable radiation array with mechanically driven system and directive elements

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0716-0

摘要： In the artificial intelligence-driven modern wireless communication system, antennas are required to be reconfigurable in terms of size according to changing application scenarios. However, conventional antennas with constant phase distributions cannot achieve enhanced gains in different reconfigurable sizes. In this paper, we propose a mechanically reconfigurable radiation array (RRA) based on miniaturized elements and a mechanically reconfigurable system to obtain gain-enhanced antennas in compact and deployed states. A five-element RRA with a phase-reconfigurable center element is designed and analyzed theoretically. The experimental sample has been fabricated, driven by a deployable frame with only one degree of freedom to realize the size and phase distribution reconfiguration simultaneously to validate the enhanced gains of RRA. The proposed RRA can be tessellated into larger arrays to achieve higher gains in other frequency regimes, such as terahertz or photonics applications with nanometer fabrication technology.

关键词： mechanism reconfigurable radiation array (RRA) compact state deployed state enhanced gain

HTML PDF 收藏

标题作者时间类型操作

Theoretical study on flow and radiation in tubular solar photocatalytic reactor

期刊论文

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propanefires in open space based on weighted multi-point source model

Jie JI, Junrui DUAN, Huaxian WAN

期刊论文

Nongray radiation from gas and soot mixtures in planar plates based on statistical narrow-band spectralmodel

Huaqiang CHU, Qiang CHENG, Huaichun ZHOU, Fengshan LIU

期刊论文

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

期刊论文

大空间内着火位置对火灾增长的影响

石龙,张瑞芳, 谢启源,付丽华

期刊论文

Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo