资源类型

期刊论文 743

会议视频 9

年份

2024 2

2023 51

2022 59

2021 64

2020 30

2019 59

2018 45

2017 36

2016 30

2015 34

2014 31

2013 26

2012 29

2011 35

2010 38

2009 36

2008 47

2007 42

2006 8

2005 8

展开 ︾

关键词

数值模拟 4

能源 3

COVID-19 2

三十烷醇 2

个人热管理 2

内禀尺度 2

冷凝水闪蒸 2

动力气垫 2

医院中子照射器I型堆 2

卫星 2

太阳能 2

水稻 2

火灾 2

绿色化工 2

32 m箱梁 1

ADV 1

ANSYS/LS-DYNA 1

Casimir效应 1

Cu(Inx 1

展开 ︾

检索范围：

排序： 展示方式：

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0672-8

摘要： Surface roughness and thermal action are of remarkable importance in the lubrication performance of mechanical components, especially in extreme conditions. However, available studies mainly focus on the full-film lubrication conditions without considering temperature rise and real 3D surface roughness due to the complexity of surface topography and temperature characteristics. Moreover, studies on the interfacial thermal behaviors of 3D rough surface lubricated contact in an extended range of working conditions remain limited. In this paper, a deterministic mixed thermal elastohydrodynamic lubrication model considering real 3D surface roughness and thermal effects is proposed. In this model, pressure and temperature are coupled with each other, the computation of elastic deformation is accelerated through the discrete convolution and fast Fourier transform method, the temperature field is calculated with the column sweeping technique, and the semi-system method is introduced to improve convergence and numerical stability under severe conditions. The model is validated by comparing its results with available published numerical and experimental results. The thermal behaviors of the contact interface are studied in a wide range of working conditions. The influences of surface roughness and thermal effect on lubrication performance are revealed. The results show that the proposed model can be used as a powerful analysis tool for lubrication performance and temperature prediction in various heavy-load, high-speed lubricated components over a wide range of lubrication conditions.

关键词： thermal elastohydrodynamic lubrication     surface roughness effect     thermal effect     temperature characteristics     severe conditions    

HTML PDF 收藏

Effect of thermal pretreatment on the surface structure of PtSn/SiO

Guozhen Xu, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma

《化学科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 417-424 doi: 10.1007/s11705-016-1583-1

摘要： The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO catalyst in acetic acid (AcOH) hydrogenation was investigated in this article. The catalysts were characterized by N physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H -O titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSn alloy was observed. Meanwhile, with the increment of thermal pretreatment temperature, Pt dispersion showed a decreasing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.

关键词： thermal pretreatment     acetic acid     hydrogenation     ethanol     PtSn/SiO2    

HTML PDF 收藏

A fully solid-state cold thermal energy storage device for car seats using shape-memory alloys

《能源前沿（英文）》 2023年 第17卷 第4期   页码 504-515 doi: 10.1007/s11708-022-0855-3

摘要： Thermal energy storage has been a pivotal technology to fill the gap between energy demands and energy supplies. As a solid-solid phase change material, shape-memory alloys (SMAs) have the inherent advantages of leakage free, no encapsulation, negligible volume variation, as well as superior energy storage properties such as high thermal conductivity (compared with ice and paraffin) and volumetric energy density, making them excellent thermal energy storage materials. Considering these characteristics, the design of the shape-memory alloy based the cold thermal energy storage system for precooling car seat application is introduced in this paper based on the proposed shape-memory alloy-based cold thermal energy storage cycle. The simulation results show that the minimum temperature of the metal boss under the seat reaches 26.2 °C at 9.85 s, which is reduced by 9.8 °C, and the energy storage efficiency of the device is 66%. The influence of initial temperature, elastocaloric materials, and the shape-memory alloy geometry scheme on the performance of car seat cold thermal energy storage devices is also discussed. Since SMAs are both solid-state refrigerants and thermal energy storage materials, hopefully the proposed concept can promote the development of more promising shape-memory alloy-based cold and hot thermal energy storage devices.

关键词： shape-memory alloy (SMA)     elastocaloric effect (eCE)     cooled seat     cold thermal energy storage    

HTML PDF 收藏

A theoretical investigation on the thermal decomposition of pyridine and the effect of H

Ji Liu, Xinrui Fan, Wei Zhao, Shi-guan Yang, Wenluan Xie, Bin Hu, Qiang Lu

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1217-1228 doi: 10.1007/s11705-020-2024-8

摘要： Pyridine is one of the main nitrogen-containing compounds in coal, and its pyrolytic mechanism to generate NO precursors (mainly NH and HCN) remains unclear. In this work, the possible pathways for the pyrolysis of pyridine to form HCN and/or NH were investigated by the density functional theory method, and the effects of H O on pyridine pyrolysis were also investigated. The results show that there are two possible reactions for the initial pyridine pyrolysis, i.e., internal hydrogen transfer and C–H bond homolysis, and that internal hydrogen transfer is more favorable. Nine possible reaction pathways following internal hydrogen transfer are obtained and analyzed. Among these pathways, pyridine prefers to produce HCN instead of NH . The existence of H O has significant effects on the decomposition of pyridine, as it participates in pyridine pyrolysis to form NH rather than HCN as the major product.

关键词： coal     pyridine     pyrolysis mechanism     NOx precursors     DFT    

HTML PDF 收藏

Effect of natural resource on improving indoor thermal environment in Chongqing

Yong DING, Baizhan LI, Qing LUO, Hong LIU, Meng LIU

《结构与土木工程前沿（英文）》 2009年 第3卷 第2期   页码 211-218 doi: 10.1007/s11709-009-0018-1

摘要： This paper analyzes the potential of natural resources to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resources including solar energy, wind, water, and earth, etc. The building form, systems, and principle of usage of natural resources are briefly analyzed through the building site decision, building form design, and computer simulation, which will be the real reference for the design of building energy efficiency.

关键词： natural resource     indoor thermal environment     renewable energy    

HTML PDF 收藏

Effect of TGO on the tensile failure behavior of thermal barrier coatings

Le WANG, Yuelan DI, Ying LIU, Haidou WANG, Haoxing YOU, Tao LIU

《机械工程前沿（英文）》 2019年 第14卷 第4期   页码 452-460 doi: 10.1007/s11465-019-0541-2

摘要： Thermally grown oxide (TGO) may be generated in thermal barrier coatings (TBCs) after high-temperature oxidation. TGO increases the internal stress of the coatings, leading to the spalling of the coatings. Scanning electron microscopy and energy-dispersive spectroscopy were used to investigate the growth characteristics, microstructure, and composition of TGO after high-temperature oxidation for 0, 10, 30, and 50 h, and the results were systematically compared. Acoustic emission (AE) signals and the strain on the coating surface under static load were measured with AE technology and digital image correlation. Results showed that TGO gradually grew and thickened with the increase in oxidation time. The thickened TGO had preferential multi-cracks at the interface of TGO and the bond layer and delayed the strain on the surface of the coating under tensile load. TGO growth resulted in the generation of pores at the interface between the TGO and bond layer. The pores produced by TGO under tensile load delayed the generation of surface cracks and thus prolonged the failure time of TBCs.

关键词： thermally grown oxides     thermal barrier coatings     acoustic emission technology     digital image correlation     pores    

HTML PDF 收藏

Effect of heat transfer coefficient of steam turbine rotor on thermal stress field under off-design condition

Jie GUO,Danmei XIE,Hengliang ZHANG,Wei JIANG,Yan ZHOU

《能源前沿（英文）》 2016年 第10卷 第1期   页码 57-64 doi: 10.1007/s11708-015-0385-3

摘要： The precise calculation of temperature and thermal stress field of steam turbine rotor under off-design conditions is of paramount significance for safe and economic operation, in which an accurate calculation of heat transfer (HT) coefficient plays a decisive role. HT coefficient changes dramatically along with working conditions. First, a finite element analysis of rotor model, applied with ordinary rotor materials, has been conducted to investigate the temperature and thermal stress difference along with the change of HT coefficient from 20 W/(m ·°C) to 20000 W/(m ·°C). Next, the differentiation between existing empirical formulas has been analyzed from the aspect of physical significance of non-dimension parameters. Finally, a verifying case of the cold startup of a 1000MW unit has been proceeded. The result shows that the accuracy of coefficient calculation when steam parameters are low has a greater influence on that of rotor temperature and thermal stress, which means a precise empirical HT coefficient formula, like the Sarkar formula is strongly recommended. When steam parameters are high and HT coefficient is larger than 10 W/(m ·°C), there will be barely any influence on the calculation of thermal stress. This research plays a constructive role in the calculation and analysis of thermal stress.

关键词： steam turbine     rotor     thermal stress     heat transfer coefficient     empirical formula    

HTML PDF 收藏

Microdamage study of granite under thermomechanical coupling based on the particle flow code

《结构与土木工程前沿（英文）》   页码 1413-1427 doi: 10.1007/s11709-023-0953-2

摘要： The thermomechanical coupling of rocks refers to the interaction between the mechanical and thermodynamic behaviors of rocks induced by temperature changes. The study of this coupling interaction is essential for understanding the mechanical and thermodynamic properties of the surrounding rocks in underground engineering. In this study, an improved temperature-dependent linear parallel bond model is introduced under the framework of a particle flow simulation. A series of numerical thermomechanical coupling tests are then conducted to calibrate the micro-parameters of the proposed model by considering the mechanical behavior of the rock under different thermomechanical loadings. Good agreement between the numerical results and experimental data are obtained, particularly in terms of the compression, tension, and elastic responses of granite. With this improved model, the thermodynamic response and underlying cracking behavior of a deep-buried tunnel under different thermal loading conditions are investigated and discussed in detail.

关键词： thermomechanical coupling effect     granite     improved linear parallel bond model     thermal property     particle flow code    

HTML PDF 收藏

Thermal-hydraulic performance of novel louvered fin using flat tube cross-flow heat exchanger

DONG Junqi, CHEN Jiangping, CHEN Zhijiu

《能源前沿（英文）》 2008年 第2卷 第1期   页码 99-106 doi: 10.1007/s11708-008-0010-9

摘要： Experimental studies were conducted to investigate the air-side heat transfer and pressure drop characteristics of a novel louvered fins and flat tube heat exchangers. A series of tests were conducted for 9 heat exchangers with different fin space and fin length, at a constant tube-side water flow rate of 2.8 m/h. The air side thermal performance data were analyzed using the effectiveness-NTU method. Results were presented as plot of Colburn factor and friction factor against the Reynolds number in the range of 500–6500. The characteristics of the heat transfer and pressure drop of different fin space and fin length were analyzed and compared. In addition, the curves of the heat transfer coefficients vs. pumping power per unit heat transfer area were plotted. Finally, the area optimization factor was used to evaluate the thermal hydraulic performance of the louvered fins with differential geometries. The results showed that the and factors increase with the decrease of the fin space and fin length, and the fin space has more obvious effect on the thermal hydraulic characteristics of the novel louvered fins.

关键词： obvious effect     different     thermal hydraulic     constant tube-side     Colburn    

HTML PDF 收藏

典型硼化合物对毛竹热降解与燃烧性能的影响

杨守禄,吴义强,卿彦,姚春花

《中国工程科学》 2014年 第16卷 第4期   页码 51-55

摘要：

利用热重和锥形量热仪研究硼酸、硼砂两种典型硼化合物对毛竹热降解和燃烧性能的影响。结果 表明：硼酸、硼砂能降低竹材的最大热解速率，缩短高温热解区间，促进残炭生成。与未处理材相比，硼酸、硼砂明显减少竹材燃烧过程中的热量释放，热释放速率降至未处理材的50 %左右，总热释放量的降幅分别达50.6 %、44.1 %。硼酸、硼砂也能抑制竹材燃烧时的烟释放，总烟释放量分别下降95.3 %、91.6 %。硼酸、硼砂处理竹材能发挥高效的阻燃抑烟功效。

关键词： 硼酸     硼砂     毛竹     热降解     燃烧性能    

HTML PDF 收藏

Effect of asphalt thin beams mixed with three nominal maximum aggregate sizes in the bending beam rheometeron the prediction of thermal properties of bituminous material

Chun-Hsing HO,María Francisca Martínez GONZÁLEZ,Cristina Pilar Martín LINARES

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 1-7 doi: 10.1007/s11709-016-0367-5

摘要： The objective of this research is to evaluate an impact of asphalt mixture beams with varying sizes of aggregate in the Bending Beam Rheometer (BBR) for testing/predicting thermal cracking properties of asphalt pavements. The BBR test has following benefits: the equipment is cheaper, it uses smaller specimens, faster conditioning, easier availability for quality control, easier to manage, etc. However some concerns have been raised: some consider that the size of the aggregate may affect the test’s results; the other concern is that such small beams cannot represent the whole properties of the asphalt pavement. To address these criticisms, imaging techniques, statistical analysis, and viscoelastic modeling are used. Asphalt thin beams prepared with three different nominal maximum aggregate size (NMAS) (12.5mm, 9.5 mm, and 4.75 mm) were tested at three different temperatures (-18°C, -24°C, and -30°C). Based on results from statistical analyses and viscoelasticity, the ratio of asphalt binders and voids and stiffness differences among the three NMAS specimens are not significant, meaning that the impact of asphalt thin beams prepared with the three NMAS on the prediction of thermal cracking is minimal and can be neglected.

关键词： bending beam rheometer     thin beams     thermal cracking    

HTML PDF 收藏

液体调速离合器中摩擦副热效应分析

洪跃,刘谨,王云根

《中国工程科学》 2003年 第5卷 第9期   页码 55-60

摘要：

液体粘性调速离合器是利用多个摩擦圆盘间的油膜剪切力来传递动力，并通过改变油膜厚度实行无级调速。由于近来工程中广泛采用聚α-稀烃型、聚酯型等合成油作润滑剂，液体粘性调速离合器在调速范围内，其摩擦副往往工作在流体润滑、混合润滑、边界润滑直到直接接触的工况。基于这些特点，笔者采用了幂律型非牛顿流体模型、Patir-Cheng的平均流量模型、GT两粗糙平面接触模型、计入油膜的惯性影响、平均能量方程、热传导方程，建立了热效应研究模型，推导了相应的计算方程式，并在流体润滑、流体混合润滑状态下，进行了数值计算与分析。

关键词： 液体调速离合器     热分析     雷诺方程     非牛顿流体     表面粗糙度    

HTML PDF 收藏

Effect of graphene and its derivatives on thermo-mechanical properties of phase change materials and

《能源前沿（英文）》 2022年 第16卷 第2期   页码 150-186 doi: 10.1007/s11708-021-0795-3

摘要： Phase change materials (PCMs) play a leading role in overcoming the growing need of advanced thermal management for the storage and release of thermal energy which is to be used for different solar applications. However, the effectiveness of PCMs is greatly affected by their poor thermal conductivity. Therefore, in the present review the progress made in deploying the graphene (Gr) in PCMs in the last decade for providing the solution to the aforementioned inadequacy is presented and discussed in detail. Gr and its derivatives ((Gr oxide (GO), Gr aerogel (GA) and Gr nanoplatelets (GNPs)) based PCMs can improve the thermal conductivity and shape stability, which may be attributed to the extra ordinary thermo-physical properties of Gr. Moreover, it is expected from this review that the advantages and disadvantages of using Gr nanoparticles provide a deep insight and help the researchers in finding out the exact basic properties and finally the applications of Gr can be enhanced.

关键词： phase change materials (PCMs)     graphene     thermal conductivity     characterization    

HTML PDF 收藏

纵向通风水平隧道火灾烟气流动特性研究

卢平,丛北华,廖光煊,范维澄,厉培德

《中国工程科学》 2004年 第6卷 第10期   页码 59-64

摘要：

地铁隧道火灾烟气控制是城市公共安全的一个重要组成部分。在分析地铁隧道火灾烟气流动主要影响因素的基础上，将地铁隧道通风和排烟系统作为一个整体考虑，引入地铁隧道火灾烟气的浮力效应和热阻效应，建立了隧道通风网络火灾模拟的数学模型，分析了地铁隧道火灾烟气逆流的临界条件、临界流速、隧道风流及烟流流速与火灾强度的变化关系，为地铁隧道火灾烟气控制和事故应急处理提供科学依据。

关键词： 地铁隧道     火灾烟气     浮力效应     热阻效应     临界风速    

HTML PDF 收藏

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

《能源前沿（英文）》 2009年 第3卷 第2期   页码 241-246 doi: 10.1007/s11708-009-0006-0

摘要： NO and N O emissions from circulating fluidized bed (CFB) boilers are determined by their formation and destruction rates in the furnace. The effect of circulating ash from a CFB boiler on NO and N O emissions were investigated in a laboratory-scale fluidized bed reactor. The results show that the residue char in circulating ash and the CO generated from the char play an important role in NO reduction and N O formation; however, active components of circulating ash such as CaO, Fe O accelerate the decomposition of N O. Experiment was also conducted on a 75 t/h CFB boiler fueled with the mixture of anthracite and biomass. The lower residue carbon content of circulating ash in this experiment is lower; therefore, the reacting rate of NO deoxidize is limited. This result verified the conclusion of laboratory research.

关键词： CFB boiler     circulating ash     NO reduction     N2O thermal decomposition     biomass    

HTML PDF 收藏

标题 作者 时间 类型 操作

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

期刊论文

Effect of thermal pretreatment on the surface structure of PtSn/SiO

Guozhen Xu, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma

期刊论文

A fully solid-state cold thermal energy storage device for car seats using shape-memory alloys

期刊论文

A theoretical investigation on the thermal decomposition of pyridine and the effect of H

Ji Liu, Xinrui Fan, Wei Zhao, Shi-guan Yang, Wenluan Xie, Bin Hu, Qiang Lu

期刊论文

Effect of natural resource on improving indoor thermal environment in Chongqing

Yong DING, Baizhan LI, Qing LUO, Hong LIU, Meng LIU

期刊论文

Effect of TGO on the tensile failure behavior of thermal barrier coatings

Le WANG, Yuelan DI, Ying LIU, Haidou WANG, Haoxing YOU, Tao LIU

期刊论文

Effect of heat transfer coefficient of steam turbine rotor on thermal stress field under off-design condition

Jie GUO,Danmei XIE,Hengliang ZHANG,Wei JIANG,Yan ZHOU

期刊论文

Microdamage study of granite under thermomechanical coupling based on the particle flow code

期刊论文

Thermal-hydraulic performance of novel louvered fin using flat tube cross-flow heat exchanger

DONG Junqi, CHEN Jiangping, CHEN Zhijiu

期刊论文

典型硼化合物对毛竹热降解与燃烧性能的影响

杨守禄,吴义强,卿彦,姚春花

期刊论文

Effect of asphalt thin beams mixed with three nominal maximum aggregate sizes in the bending beam rheometeron the prediction of thermal properties of bituminous material

Chun-Hsing HO,María Francisca Martínez GONZÁLEZ,Cristina Pilar Martín LINARES

期刊论文

液体调速离合器中摩擦副热效应分析

洪跃,刘谨,王云根

期刊论文

Effect of graphene and its derivatives on thermo-mechanical properties of phase change materials and

期刊论文

纵向通风水平隧道火灾烟气流动特性研究

卢平,丛北华,廖光煊,范维澄,厉培德

期刊论文

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

期刊论文