检索结果-内蒙古大学图书馆

第七届天地应用两相系统国际研讨会

作者： J.J.Wei J.F.Zhao D.Guo Y.H.Zhang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University28 Xianning XiluXi’an 710049China 2National Microgravity LaboratoryInstitute of MechanicsChinese Academy of Sciences 15 Beisihuan XiluBeijing 100190China

来源：评论

学校读者我要写书评

暂无评论

Combustion and emission characteristics of a turbo-charged common rail diesel engine fuelled with diesel-biodiesel-DEE blends

引用

能源前沿 2011年第1期5卷 104-114页

作者： Ni ZHANG Zuohua HUANG Xiangang WANG Bin ZHENG State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049China

The combustion and emission characteristics of a turbo-charged, common rail diesel engine fuelled with diesel-biodiesel-DEE blends were investigated. The study repons that the brake-specific fuel consumption of dieselbiodiesel-DEE blends increases with increase of oxygenated fuel fractions in the blends. Brake thermal efficiency shows little variation when operating on different dieselbiodiesel-DEE blends. At a low load, the NOx emission of the diesel-biodiesel-DEE blends exhibits little variation in comparison with the biodiesel fraction. The NOx emission slightly increases with increase in the biodiesel fraction in diesel-biodiesel-DEE blends at medium load. However,the NOx emission increases remarkably with increase of the biodiesel fraction at high load. Particle mass concentration decreases significantly with increase of the oxygenated-fuels fraction at all engine speeds and loads;particle number concentration decreases remarkably with increase of the oxygenated-fuels fraction. HC and CO emissions decrease with increasing oxygenated-fuels fraction in these blends.

关键词： Combustion particulate emissions dieselbiodiesel-DEE blend diesel engine

来源：评论

学校读者我要写书评

暂无评论

Influence of cetane number improver on performance and emissions of a common-rail diesel engine fueled with biodiesel-methanol blend

引用

能源前沿 2011年第4期5卷 412-418页

作者： Wu YU Gen CHEN Zuohua HUANG State Key Laboratory of Multiphase Flow in Power Engineering Xi'anJiaotong University Xi'an 710049 China

In this paper,the effect ofcetane number (CN)improver on performance and emissions,including particulate number concentration and size distribution,of a turbocharged,common-rail diesel engine fueled with biodiesel-methanol were *** volume fractions (0.3％ and 0.6％) of CN improver were added to BM30 (30％ of methanol in the biodiesel-methanol blend) in the *** results show that,compared with those of biodiesel-methanol blend,the peak value of cylinder pressure increases,the second peak of heat release rate decreases,the start of second heat release are advanced,and the fuel economy and thermal efficiency are improved when CN improver is added to biodiesel-methanol ***,CO and HC emissions decrease,NOx emission varies little and smoke emissions increase ***,exhaust particles of BM30 mainly distribute in nanosize ***,particle number concentration decreases and peak of size distribution profile shifts toward large size direction.

关键词： biodiesel methanol common-rail (CR) dieselengine cetane number (CN) improver

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation of the heat flux distribution in a solar cavity receiver

引用

能源前沿 2011年第1期5卷 98-103页

作者： Yueshe WANG Xunwei DONG Jinjia WEI Hui JIN State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

In the solar tower power plant, the receiver is one of the main components of efficient concentrating solar collector systems. In the design of the receiver, the heat flux distribution in the cavity should be considered first. In this study, a numerical simulation using the Monte Carlo Method has been conducted on the heat flux distribution in the cavity receiver, which consists of six lateral faces and floor and roof planes, with an aperture of 2.0m×2.0m on the front face. The mathematics and physical models of a single solar ray's launching,reflection, and absorption were proposed. By tracing every solar ray, the distribution of heat flux density in the cavity receiver was obtained. The numerical results show that the solar flux distribution on the absorbing panels is similar to that of CESA-I's. When the reradiation from walls was considered, the detailed heat flux distributions were issued, in which 49.10% of the total incident energy was absorbed by the central panels,47.02% by the side panels, and 3.88% was overflowed from the aperture. Regarding the peak heat flux, the value of up to 1196.406 kW/m2 was obtained in the center of absorbing panels. These results provide necessary data for the structure design of cavity receiver and the local thermal stress analysis for boiling and superheated panels.

关键词： solar cavity receiver Monte Carlo method heat flux distribution

来源：评论

学校读者我要写书评

暂无评论

Bubble Behavior and Heat Transfer of Nucleate Pool Boiling on Micro-Pin-Finned Surface in Microgravity

引用

Chinese Physics Letters 2011年第1期28卷 160-163页

作者： WEI Jin-Jia XUE Yan-Fang ZHAO Jian-Fu LI Jing State Key Laboratory of Multiphase Flow in Power Engineering Xi 'an Jiaotong University Xi'an 710049 Key Laboratory of Microgravity (National Microgravity Laboratory)/CAS Institute of Mechanics Chinese Academy of Sciences Heijing 100190

Nucleate pool boiling on micro-pin-finned surface structure is proposed for efficiently cooling electronic compo- nents with high heat flux in microgravity, and was verified by experiments performed utilizing the drop tower Beijing. Micro-pin-fins with tile dimensions of 50 × （30 μm2 （thickness × height） and the space of 50 μm were fabricated on the chip surface by the dry etching technique. FC-72 was used as the working fluid. Nucleate pool boiling of FC-72 on a smooth surface was also tested for comparison. Unlike much obvious deterioration of heat transfer of nucleate pool boiling on the smooth surface in microgravity, constant heater surface temperature of nucleate pool boiling for the micro-pin-finned surface was observed, even though a large coalesced bubble completely covered the surface under microgravity condition. The performance of high efficient heat transfer on micro-pin-finned surface is independent of the gravity, which stems from the sufficient supply of fresh liquid to the heater surface due to the capillary forces.

关键词： Fluid dynamics Surfaces, interfaces and thin films

来源：评论

学校读者我要写书评

暂无评论

Preparation and Photocatalytic Activities of Magnetic TiO2/Fe3O4 Composite Nanoparticles

Preparation and Photocatalytic Activities of Magnetic TiO2/F...

引用

UK-China Symposium of New Energy Materials and Nanotechnology(2012年中英纳米技术和新能源材料研讨会)

作者： SU Jie CHENG Wen MA Xia LIU Rui LI Huiqiang YAN Yanli Xi''an University of Technology Xi''an 710048China Xi''an 710049 China Key Laboratory of Northwest Water Resources Environment and Ecology Ministry of Education State Key Laboratory of Multiphase Flow in Power Engineering Xi''an Jiao tong University Xi''an University of Technology Xi''an 710048China Key Laboratory of Northwest Water ResourcesEnvironment and Ecology Ministry of Education

来源：评论

学校读者我要写书评

暂无评论

Ab initio investigation of defect formation at ZrO2-CeO2 interfaces

引用

Physical Review B 2012年第8期86卷 085407-085407页

作者： Marco Fronzi Silvia Cereda Yoshitaka Tateyama Alessandro De Vita Enrico Traversa International Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS) Tsukuba Japan Physics Department King's College London Strand London United Kingdom International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xian Jiaotong University Xian Shaanxi China

The structural and electronic properties of low index (100) and (111) ZrO2-CeO2 interfaces are analyzed on the basis of density functional theory calculations. The formation energy and relative stability of substitutional defects, oxygen vacancies, and vacancy-dopant complexes are investigated for the (100) orientation. By comparing these results with the ones obtained in bulk structures, we provide a possible explanation for the higher experimental ionic conductivity measured at the interface.

关键词： ZIRCONIUM oxide CERIUM oxides INTERFACES (Physical sciences) CRYSTAL defects ELECTRONIC structure

来源：评论

学校读者我要写书评

暂无评论

Effect of nozzle size on the surface heat transfer dynamics during cryogen spray cooling in dermatologic laser surgery

引用

Zhongguo Jiguang/Chinese Journal of Lasers 2012年第3期39卷

作者： Zhou, Zhifu Wang, Rui Wang, Guoxiang Guo, Liejin Chen, Bin Wang, Yueshe State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 China Department of Mechanical Engineering University of Akron Akron OH 44325 United States

Cryogen spray cooling (CSC) in conjunction with laser therapy has been the clinical standard for hypervascular lesions. In order to optimize nozzle and enhance the cooling efficiency to improve the treatment of laser surgery, an experimental system of transient cryogen spray cooling is built and eight straight-tube nozzles with different diameter and length are designed. A thin film thermocouple is directly deposited on the cooling surface to measure the surface temperature during the cryogen spray cooling. An analytical expression based on Fourier's law and Duhamel's theorem is used to calculate surface heat flux from the temperature measurements. Based on the measurements and calculations, the effect of the eight straight-tube nozzles on the heat transfer dynamics of the cooling surface and the atomization characterics are comparatively studied. Additionally, the criterion to evaluate the cooling efficiency of different nozzles is proposed, and the variation of heat extraction from the cooling surface with different spray distances by different nozzles is given.

关键词： Heat flux

来源：评论

学校读者我要写书评

暂无评论

Experimental study of natural convection in horizontally-positioned open-celled metal foams

Experimental study of natural convection in horizontally-pos...

引用

International Conference on Materials for Renewable Energy and Environment

作者： Xu, Z.G. Qu, Z.G. Zhao, C.Y. State Key Laboratory of Multiphase Flow School of Energy and Power Engineering Xi'An Jiaotong University China

ISBN: (纸本)9781612847504

Experimental study of air natural convection in horizontally-positioned copper metallic foams with open cells was conducted. Temperature distributions on the heating surface were tested under different heating power for foam samples having different porosities and pore densities. The effects of porosity and pore density on the total thermal resistance of the foam sample were quantified. It is found that the porous surface can enhance the natural convection and reduce the thermal resistance by about 20% in comparison with a smooth surface. The surface area density and mass flow rate in natural convection are affected by porosity and pore density simultaneously. When the porosity is relative small (Ε = 90%), there exits a critical value of the Gr number (turning point) for two pore densities (10ppi and 40ppi). When the Gr number is less than this critical value, the foam with a higher pore density has the lower total thermal resistance, whereas when the Gr number exceeds the turning point value, the opposite holds. If the porosity is increased to Ε = 95%, the foam with a higher pore density has the lower thermal resistance in the whole experimental range. When the porosity and pore density is the same, the foam with smaller size has the higher thermal resistance in the whole experimental range. If the size is relatively small (10010050mm), for the two pore densities studied (20ppi and 80ppi), there exits a critical value of the Gr number (turning point). The foam with a lower porosity(Ε = 90%) has the lower thermal resistance and the decrease is more obvious for the case of *** the size is relatively big(10010080mm),there exists a critical value of the Gr number (turning point) only for the case of 10ppi. When the Gr number is less than this critical value, the foam with a higher porosity (Ε = 95%) has the higher total thermal resistance, the opposite holds. While for the other two pore densities (20ppi and 40ppi), there is no turning point. The foam with a highe

关键词： Natural convection

来源：评论

学校读者我要写书评

暂无评论

Optimization on ignition timing and EGR ratio of a spark-ignition engine fuelled with natural gas-hydrogen blends

Optimization on ignition timing and EGR ratio of a spark-ign...

引用

SAE 2011 World Congress and Exhibition

作者： Hu, Erjiang Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi'An Jiaotong University Xi'an 710049 China

In this paper, 20%H2 (20% hydrogen in natural gas-hydrogen blends, by volume) is selected as the test fuel, and the ignition timing and EGR ratio are adjusted to optimize the performance, combustion, and emissions of a natural gas-hydrogen engine. An experimental investigation on the effect of ignition timings, EGR ratios on combustion behaviors and emissions of a spark-ignition engine fuelled with natural-gas and hydrogen blends was conducted. When increasing the ignition timing at specified EGR ratio, engine power output will give its peak value at MBT timing. Large EGR introduction decreases engine power output and increases combustion duration. Effective thermal efficiency shows an increasing trend at the small EGR ratio and a decreasing trend with further increasing EGR ratio. With advancing the ignition timing, the flame development duration is increased, and the rapid combustion duration and total combustion duration are decreased. All of these three kinds of combustion duration are increased with the increase of EGR ratio. HC concentration is decreased and NOx concentration is increased with advancing the ignition timing while CO emission varies little with the ignition timing. NOx concentration is decreased with the increase of EGR ratio. HC emission is increased with the increase of EGR ratio. CO and CO2 emissions show little variations with the EGR ratio and ignition timing. Based on the above analysis, a MAP containing ignition timings and EGR ratios for 20%H2 fuel blend is presented, and this will provide the reference and guidance to engine designers and engineers. In addition, through optimizing ignition timing and EGR ratio, high efficiency and low emission spark-ignition engine can be realized fueled with natural gas-hydrogen blends. Copyright © 2011 SAE International.

关键词： Natural gas

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：