资源类型

期刊论文 550

会议视频 8

年份

2023 50

2022 52

2021 47

2020 49

2019 33

2018 34

2017 27

2016 30

2015 15

2014 24

2013 19

2012 11

2011 23

2010 29

2009 28

2008 26

2007 24

2006 7

2005 5

2004 2

展开 ︾

关键词

环境 3

乳液 2

内禀尺度 2

双层辉光离子渗金属 2

地球物理 2

数值模拟 2

无氢渗碳 2

细水雾 2

&alpha 1

2D—3D配准 1

6G 1

CO2利用 1

Cuk矩阵变换器 1

GDM过滤技术 1

GPS数据 1

GPS浮标 1

GaAs基微结构材料 1

PB-PSOI 1

PHEMT 1

展开 ︾

检索范围:

排序: 展示方式:

Significant progress in solution of nonlinear equations at displacement of structure and heat transferextended surface by new AGM approach

M. R. AKBARI,D. D. GANJI,M. NIMAFAR,A. R. AHMADI

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 390-401 doi: 10.1007/s11465-014-0313-y

摘要:

In this paper, we aim to promote the capability of solving two complicated nonlinear differential equations: 1) Static analysis of the structure with variable cross section areas and materials with slope-deflection method; 2) the problem of one dimensional heat transfer with a logarithmic various surface A(x) and a logarithmic various heat generation G(x) with a simple and innovative approach entitled “Akbari-Ganji’s method” (AGM). Comparisons are made between AGM and numerical method, the results of which reveal that this method is very effective and simple and can be applied for other nonlinear problems. It is significant that there are some valuable advantages in this method and also most of the differential equations sets can be answered in this manner while in other methods there is no guarantee to obtain the good results up to now. Brief excellences of this method compared to other approaches are as follows: 1) Differential equations can be solved directly by this method; 2) without any dimensionless procedure, equation(s) can be solved; 3) it is not necessary to convert variables into new ones. According to the aforementioned assertions which are proved in this case study, the process of solving nonlinear equation(s) is very easy and convenient in comparison to other methods.

关键词: AGM     extended surface     heat transfer     slope-deflection method    

Numerical analysis on heat transfer enhancement by longitudinal vortex based on field synergy principle

WU Junmei, TAO Wenquan

《能源前沿(英文)》 2007年 第1卷 第3期   页码 365-369 doi: 10.1007/s11708-007-0055-1

摘要: Three-dimensional numerical simulation results are presented for a fin-and-tube heat transfer surface with vortex generators. The effects of the Reynolds number (from 800 to 2 000) and the attack angle (30º and 45º) of a delta winglet vortex generator are examined. The numerical results are analyzed on the basis of the field synergy principle to explain the inherent mechanism of heat transfer enhancement by longitudinal vortex. The secondary flow generated by the vortex generators causes the reduction of the intersection angle between the velocity and fluid temperature gradients. In addition, the computational evaluations indicate that the heat transfer enhancement of delta winglet pairs for an aligned tube bank fin-and-tube surface is more significant than that for a staggered tube bank fin-and-tube surface. The heat transfer enhancement of the delta winglet pairs with an attack angle of 45º is larger than that with an angle of 30º. The delta winglet pair with an attack angle of 45º leads to an increase in pressure drop, while the delta winglet pair with the 30º angle results in a slight decrease. The heat transfer enhancement under identical pumping power condition for the attack angle of 30º is larger than that for the attack angle of 45º either for staggered or for aligned tube bank arrangement.

关键词: computational     inherent mechanism     staggered     decrease     transfer surface    

Numerical investigation and analysis of heat transfer enhancement in channel by longitudinal vortex based

TAO Wenquan, WU Junmei

《能源前沿(英文)》 2008年 第2卷 第1期   页码 71-78 doi: 10.1007/s11708-008-0001-x

摘要: 3-D numerical simulations were presented for laminar flow and heat transfer characteristics in a rectangular channel with vortex generators. The effects of Reynolds number (from 800 to 3 000), the attack angle of vortex generator (from 15° to 90°) and the shape of vortex generator were examined. The numerical results were analyzed based on the field synergy principle. It is found that the inherent mechanism of the heat transfer enhancement by longitudinal vortex can be explained by the field synergy principle, that is, the second flow generated by vortex generators results in the reduction of the intersection angle between the velocity and fluid temperature gradient. The longitudinal vortex improves the field synergy of the large downstream region of longitudinal vortex generator (LVG) and the region near (LVG); however, transverse vortex only improves the synergy of the region near vortex generator. Thus, longitudinal vortex can enhance the integral heat transfer of the flow field, while transverse vortex can only enhance the local heat transfer. The synergy angle decreases with the increase of Reynolds number for the channel with LVG to differ from the result obtained from the plain channel, and the triangle winglet performs better than the rectanglar one under the same surface area condition.

关键词: inherent mechanism     integral     surface     rectanglar     longitudinal    

Experimental study of the effects of structured surface geometry on water spray cooling performance in

Minghou LIU, Yaqing WANG, Dong LIU, Kan XU, Yiliang CHEN

《能源前沿(英文)》 2011年 第5卷 第1期   页码 75-82 doi: 10.1007/s11708-010-0014-0

摘要: Experiments were conducted to study the effects of enhanced surfaces on heat transfer performance during water spray cooling in non-boiling regime. The surface enhancement is straight fin. The structures were machined on the top surface of heated copper blocks with a cross-sectional area of 10 mm×10 mm. The spray was performed using Unijet full cone nozzles with a volumetric flux of 0.044–0.053 m /(m ·s) and a nozzle height of 17 mm. It is found that the heat transfer is obviously enhanced for straight fin surfaces relative to the flat surface. However, the increment decreases as the fin height increases. For flat surface and enhanced surfaces with a fin height of 0.1 mm and 0.2 mm, as the coolant flux increases, the heat flux increases as well. However, for finned surface with a height of 0.4 mm, the heat flux is not sensitive to the coolant volumetric flux. Changed film thickness and the form of water/surface interaction due to an enhanced surface structure (different fin height) are the main reasons for changing of the local heat transfer coefficient.

关键词: spray cooling     finned surface     heat transfer    

Assessing the impact on groundwater safety of inter-basin water transfer using a coupled modeling approach

Haifeng JIA,Shidong LIANG,Yansong ZHANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 84-95 doi: 10.1007/s11783-014-0741-2

摘要: Surface water and groundwater always behave in a coupled manner and are major components of hydrologic cycle. However, surface water simulation models and groundwater simulation models are run separately most of the time. Few models focus on the impact of hydraulic changes in the surface water flows on the groundwater, or specifically, the impact of a water transfer project to fill a seasonally dry channel. In this study, a linked surface water and groundwater simulation model was developed to assess the impact of a trans-basin water diversion project on the groundwater. A typical plain area east of Beijing was selected as a case study, representing Beijing’s main source of groundwater used for drinking water. A surface water quality model of the Chaobai River was developed based on the Water Quality Analysis Simulation Program (WASP), and a groundwater model was developed based on the Modular Finite-Difference Groundwater Flow Model (MODFLOW) and the Modular 3-D transport model (MT3D). The results of the surface water simulation were used as input for the groundwater simulation. Water levels and four contaminants (NH -N, COD , F, As) were simulated. With the same initial and boundary conditions, scenario analyses were performed to quantify the impact of different quantities of diversion water on the groundwater environment. The results showed the water quality of the groundwater sources was not significantly affected.

关键词: surface water     groundwater     linked model     groundwater safety impact assessment     water diversion    

Augmentation of natural convective heat transfer by acoustic cavitation

Jun CAI, Xiulan HUAI, Shiqiang LIANG, Xunfeng LI,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 313-318 doi: 10.1007/s11708-009-0064-3

摘要: An experimental study was conducted to investigate the effects of acoustic cavitation on natural convective heat transfer from a horizontal circular tube. The experimental results indicated that heat transfer could be enhanced by acoustic cavitation and had the best effect when the head of the ultrasonic transducer was over the midpoint of the circular tube, and the distance between the head and the tube equaled 15 mm. The augmentation at low heat flux was better than that in the case of high heat flux. Based on experimental results, the correlation formula of Nusselt number for water was obtained.

关键词: heat transfer enhancement     augmentation     acoustic cavitation     acoustic streaming     convective heat transfer    

嫦娥1号卫星微波探月技术机理和应用研究

姜景山,王振占,李芸

《中国工程科学》 2008年 第10卷 第6期   页码 16-22

摘要:

微波探测仪是嫦娥1号卫星有效载荷之一,主要用于测量不同深度的月壤微波辐射亮温,进而反演月壤厚度的信息并对月球的3He资源量和分布进行评估。这是国际上第一次利用被动微波遥感探测器在月球轨道直接测量月表亮温信息。因此,对月壤辐射传输模型的研究是及其必要的。文章分析了月球微波探测的机理和存在的问题,并给出了初步解决途径。

关键词: 嫦娥1号微波探测仪     遥感     月壤     微波辐射传输    

Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater

Foued CHABANE,Nesrine HATRAF,Noureddine MOUMMI

《能源前沿(英文)》 2014年 第8卷 第2期   页码 160-172 doi: 10.1007/s11708-014-0321-y

摘要: This paper presents an experimental analysis of a single pass solar air collector with, and without using baffle fin. The heat transfer coefficient between the absorber plate and air can be considerably increased by using artificial roughness on the bottom plate and under the absorber plate of a solar air heater duct. An experimental study has been conducted to investigate the effect of roughness and operating parameters on heat transfer. The investigation has covered the range of Reynolds number from 1259 to 2517 depending on types of the configuration of the solar collectors. Based on the experimental data, values of Nusselt number have been determined for different values of configurations and operating parameters. To determine the enhancement in heat transfer and increment in thermal efficiency, the values of Nusselt have been compared with those of smooth duct under similar flow conditions.

关键词: Nusselt number     flow rate     heat transfer     heat transfer coefficient     thermal efficiency     forced convection    

Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder heat transfer

Jizu LV, Minli BAI, Long ZHOU, Jian ZHOU,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 392-401 doi: 10.1007/s11708-009-0066-1

摘要: Combustion chamber components (cylinder head-cylinder liner-piston assembly-oil film) were treated as a coupled body. Based on the three-dimensional numerical simulation of the heat transfer of the coupled body, a coupled three-dimensional calculation model for the in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupling method, which adopts the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components. The model was applied in the investigation of the influence of space non-uniformity in heat transfer among combustion chamber components on in-cylinder heat transfer. The results show that the effect of wall temperature space non-uniform distribution of combustion chamber components on heat transfer happens mainly at the end of the compression stroke and expansion stroke. Therefore, it can be concluded that wall temperature space non-uniform distribution of combustion chamber components would influence heat transfer during the intake and exhaust stroke obviously.

关键词: heat transfer     space non-uniformity     soot emission     in-cylinder     diesel    

Heat transfer coefficient of wheel rim of large capacity steam turbines

SHI Jinyuan, DENG Zhicheng, YANG Yu, JUN Ganwen

《能源前沿(英文)》 2008年 第2卷 第1期   页码 20-24 doi: 10.1007/s11708-008-0015-4

摘要: A way of calculating the overall equivalent heat transfer coefficient of wheel rims of large capacity steam turbines is presented. The method and formula to calculate the mean forced convection heat-transfer coefficient of the surface of the blade and for the bottom wall of the blade passage, are introduced. The heat transmission from the blade to the rim was simplified by analogy to heat transmission in the fins. A fin heat transfer model was then used to calculate the equivalent heat transfer coefficient of the blade passage. The overall equivalent heat transfer coefficient of the wheel rim was then calculated using a cylindrical surface model. A practical calculation example was presented. The proposed method helps determine the heat transfer boundary conditions in finite element analyses of temperature and thermal stress fields of steam turbine rotors.

关键词: convection heat-transfer     capacity     heat-transfer coefficient     bottom     transmission    

Review of the LNG intermediate fluid vaporizer and its heat transfer characteristics

《能源前沿(英文)》 2022年 第16卷 第3期   页码 429-444 doi: 10.1007/s11708-021-0747-y

摘要: The intermediate fluid vaporizer (IFV), different from other liquefied natural gas (LNG) vaporizers, has many advantages and has shown a great potential for future applications. In this present paper, studies of IFV and its heat transfer characteristics in the LNG vaporization unit E2 are systematically reviewed. The research methods involved include theoretical analysis, experimental investigation, numerical simulation, and process simulation. First, relevant studies on the overall calculation and system design of IFV are summarized, including the structural innovation design, the thermal calculation model, and the selection of different intermediate fluids. Moreover, studies on the fluid flow and heat transfer behaviors of the supercritical LNG inside the tubes and the condensation heat transfer of the intermediate fluid outside the tubes are summarized. In the thermal calculations of the IFV, the selections of the existing heat transfer correlations about the intermediate fluids are inconsistent in different studies, and there lacks the accuracy evaluation of those correlations or comparison with experimental data. Furthermore, corresponding experiments or numerical simulations on the cryogenic condensation heat transfer outside the tubes in the IFV need to be further improved, compared to those in the refrigeration and air-conditioning temperature range. Therefore, suggestions for further studies of IFV are provided as well.

关键词: intermediate fluid vaporizer     design of structure and intermediate fluid     condensation heat transfer    

Improving hole transfer of boron nitride quantum dots modified PDI for efficient photodegradation

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1718-1727 doi: 10.1007/s11705-023-2319-7

摘要: In recent years, organic photocatalyst under visible-light absorption has shown significant potential for solving environmental problems. However, it is still a great challenge for constructing a highly active organic photocatalyst due to the low separation efficiency of photogenerated carriers. Herein, an effective and robust photocatalyst perylene-3,4,9,10-tetracarboxylic diamide/boron nitride quantum dots (PDI/BNQDs), consisting of self-assemble PDI with π–π stacking structure and BNQDs, has been constructed and researched under visible light irradiation. The PDI/BNQDs composite gradually increases organic pollutant photodegradation with the loading amount of BNQDs. With 10 mL of BNQDs solution added (PDI/BNQDs-10), the organic pollutant photodegradation performance reaches a maximum, about 6.16 times higher with methylene blue and 1.68 times higher with ciprofloxacin than that of pure PDI supramolecular. The enhancement is attributed to improved separation of photogenerated carriers from self-assembled PDI by BNQDs due to their preeminent ability to extract holes. This work is significant for the supplement of PDI supramolecular composite materials. We believe that this photocatalytic design is capable of expanding organic semiconductors’ potential for their applications in photocatalysis.

关键词: PDI     boron nitride     quantum dots     photocatalysis     hole transfer    

A new heat transfer correlation for supercritical fluids

Yanhua YANG, Xu CHENG, Shanfang HUANG

《能源前沿(英文)》 2009年 第3卷 第2期   页码 226-232 doi: 10.1007/s11708-009-0022-0

摘要: A new method of heat transfer prediction in supercritical fluids is presented. Emphasis is put on the simplicity of the correlation structure and its explicit coupling with physical phenomena. Assessment of qualitative behaviour of heat transfer is conducted based on existing test data and experience gathered from open literature. Based on phenomenological analysis and test data evaluation, a single dimensionless number, the acceleration number, is introduced to correct the deviation of heat transfer from its conventional behaviour, which is predicted by the Dittus-Boelter equation. The new correlation structure excludes direct dependence of heat transfer coefficient on wall surface temperature and eliminates possible numerical convergence. The uncertainty analysis of test data provides information about the sources and the levels of uncertainties of various parameters and is highly required for the selection of both the dimensionless parameters implemented into the heat transfer correlation and the test data for the development and validation of new correlations. Comparison of various heat transfer correlations with the selected test data shows that the new correlation agrees better with the test data than other correlations selected from the open literature.

关键词: super critical fluids     heat transfer     circular tubes     prediction method    

Insights into the electron transfer mechanisms of permanganate activation by carbon nanotube membrane

《环境科学与工程前沿(英文)》 2023年 第17卷 第9期 doi: 10.1007/s11783-023-1706-0

摘要:

● A CNT filter enabled effective KMnO4 activation via facilitated electron transfer.

关键词: KMnO4     Carbon nanotubes     Non-radical pathway     Electron transfer     Water treatment    

Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 385-391 doi: 10.1007/s11705-011-1101-4

摘要: This paper presents the distribution of a solute undergoing a first order chemical reaction in an axisymmetric laminar boundary layer flow along a stretching cylinder. Velocity slip condition at the boundary is used instead of no-slip condition. Similarity transformations are used to convert the partial differential equations corresponding to momentum and concentration into highly nonlinear ordinary differential equations. Numerical solutions of these equations are obtained by the shooting method. The velocity decreases with increasing slip parameter. The skin friction as well as the mass transfer rate at the surface is larger for a cylinder than for a flat plate.

关键词: boundary layer     stretching cylinder     partial slip     mass transfer     similarity solution    

标题 作者 时间 类型 操作

Significant progress in solution of nonlinear equations at displacement of structure and heat transferextended surface by new AGM approach

M. R. AKBARI,D. D. GANJI,M. NIMAFAR,A. R. AHMADI

期刊论文

Numerical analysis on heat transfer enhancement by longitudinal vortex based on field synergy principle

WU Junmei, TAO Wenquan

期刊论文

Numerical investigation and analysis of heat transfer enhancement in channel by longitudinal vortex based

TAO Wenquan, WU Junmei

期刊论文

Experimental study of the effects of structured surface geometry on water spray cooling performance in

Minghou LIU, Yaqing WANG, Dong LIU, Kan XU, Yiliang CHEN

期刊论文

Assessing the impact on groundwater safety of inter-basin water transfer using a coupled modeling approach

Haifeng JIA,Shidong LIANG,Yansong ZHANG

期刊论文

Augmentation of natural convective heat transfer by acoustic cavitation

Jun CAI, Xiulan HUAI, Shiqiang LIANG, Xunfeng LI,

期刊论文

嫦娥1号卫星微波探月技术机理和应用研究

姜景山,王振占,李芸

期刊论文

Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater

Foued CHABANE,Nesrine HATRAF,Noureddine MOUMMI

期刊论文

Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder heat transfer

Jizu LV, Minli BAI, Long ZHOU, Jian ZHOU,

期刊论文

Heat transfer coefficient of wheel rim of large capacity steam turbines

SHI Jinyuan, DENG Zhicheng, YANG Yu, JUN Ganwen

期刊论文

Review of the LNG intermediate fluid vaporizer and its heat transfer characteristics

期刊论文

Improving hole transfer of boron nitride quantum dots modified PDI for efficient photodegradation

期刊论文

A new heat transfer correlation for supercritical fluids

Yanhua YANG, Xu CHENG, Shanfang HUANG

期刊论文

Insights into the electron transfer mechanisms of permanganate activation by carbon nanotube membrane

期刊论文

Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

期刊论文