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Numerical Simulation of Temperature Field in Nanostructured Al_2O_3-13TiO_2 Feedstock in Supersonic Plasma Spraying

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稀有金属材料与工程 2012年第S1期41卷 81-84页

作者： Li Changqing,Zhu Youli,Ma Shining,Song Wei Department of Remanufacture Engineering,academy of Armored Force Engineering,Beijing 100072,China acad Armored Forces engn Dept Remanufacture Engn Beijing 100072 Peoples R China

Velocity and temperature of nanostructured Al2O3-13TiO2 feedstocks in supersonic plasma spraying was detected applying CCD thermal spray *** on the detect results,temperature field in the feedstock in spraying process was analyzed via finite element *** shows that the highest velocity of the flying particles exceed to 800m/*** the increase of spraying distance,velocity decline *** temperature of the feedstock increase firstly and then decrease and the highest temperature exceed to 2600℃.Internal temperature of the feedstock is higher than the melting point when the distance reaches to *** the spraying distance increase,temperature gradient in the particle decreased gradually.

关键词： supersonic plasma spraying nanostructured feedstock CCD image analysis numerical simulation

Study on Adsorption of Water in MCM41 Containing Metal Ions by Molecular Dynamic Simulations

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Journal of Thermal Science 2004年第2期13卷 187-192,132页

作者： Shiqiang Liang Jingzhong Xu Jian Chen Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

To clarify whether the adsorption of water in MCM41 can be promoted by introducing some metal ions onto its surface, molecular dynamics simulations were carried out to investigate the behavior of some water molecules confined in mesoporous MCM41 whose pore size was tailored to 2.5 nm. Pure silica MCM41 as well as those containing some metal ions such as Al3+, Cu2+, and La3+ was simulated, and by observing the local average density distribution of particles, we found that both the MCM41 containing Al3+ and that of La3+ performed higher adsorption and lower desorption temperature. It is concluded that the adsorption is improved mainly owing to the diversities of polarity, active sites, and structure imported by these metal ions.

关键词： MCM41 molecular dynamics adsorption.

Experimental Study on the Dynamic Characteristics of a Gas Turbine Combustor Burning Syn-gas

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Journal of Thermal Science 2004年第4期13卷 376-381页

作者： Yu Lei Gang Xu Aibing Fang Chaoqun Nie Weiguang Huang Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

The present study focused on the development of a full-scale gas turbine combustor burning syn-gas from the coal-based multi-production. The dynamic features of a variety of parameters of the combustor, such as temperature and pressure during the procedures of startup and thermal load shifting, were measured and analyzed. The frequency and power spectrum of pressure fluctuation were analyzed by applying FFT and 1D continuous MORLET wavelet methods. The results show that the pressure fluctuation has distinct patterns during startup and load-transition procedures. The relationship between these dynamic features and the stability, safety and efficiency of gas turbine combustors burning syn-gas are preliminarily discussed.

关键词： gas turbine combustor dynamic characteristics frequency and power spectrum analyses.

Applications of Electrical Capacitance Tomography in Two Phase Flow Visualization

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Journal of Thermal Science 2004年第2期13卷 179-186页

作者： Shi Liu Runsheng Yan Haigang Wang Fan Jiang Xiangyun Dong Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

The successful application of Electrical Capacitance Tomography (ECT) depends heavily on the image reconstruction speed and quality. The two requirements usually cannot be satisfied simultaneously. Also, for a large number of acquired 2D ECT images, a 3D presentation of them is much desired to track the variations of the material distribution in a third dimension. To facilitate ECT for practical flow analyses in process engineering, the authors have recently developed algorithms for 3D image presentation and for online iterative image reconstruction that only takes the same time as a linear back projection method but yields good image qualities as the Landweber iterative method does. The new methods have been successfully applied to visualize several classes of two phase flows, namely fluidization, cyclone separation, circulating rate determination in circulating fluidized beds, pneumatic conveying, rotating drum mixing. Special characteristics in each case have been discussed and valuable results are obtained, which are reported in this paper.

关键词： ECT two phase flow visualization.

Geometry Effects on Aerodynamics Performance of a Low Aspect Ratio Turbine Nozzle

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Journal of Thermal Science 2004年第4期13卷 289-296页

作者： Naixing Chen Hongwu Zhang Yanji Xu Weiguang Huang Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

This paper describes the influence of some geometric parameters on aerodynamics performance of a low-aspect-ratio turbine blading designed by a novel method developed at the Institute of Engineering Thermophysics, Chinese academy of Sciences. This is a part of the study on aerodynamics optimization of turbomachinery. It follows the development of the basic ideas in the turbomachinery aerodynamics research project at the institute. The present paper concentrates mainly on the effects of geometry, such as stagger angle, leading and trailing edge thickness, maximum thickness and its location on adiabatic efficiency, total pressure ratio and mass flow rate. The study was performed and assessed for a low-aspect ratio turbine nozzle using 3D steady Reynolds-averaged N.S. solver. Using the knowledge of the flow physics analysis an optimized turbine nozzle was obtained.

关键词： 3D aerodynamics of turbomachinery turbine design optimization geometry effect.

Local Convective Heat Transfer from a Horizontal Tube in an Acoustic Cavitation Field

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Journal of Thermal Science 2004年第4期13卷 338-343页

作者： Dingwei Zhou Xuegong Hu Dengying Liu Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

An experiment has been carried out to investigate the local convective heat transfer from a horizontal circular copper tube in an acoustic cavitation field. The effects of acoustical parameters (including sound source intensity, the vibrator location and sound distance), fluid temperature and thermophysical properties of working fluid on heat transfer enhancement were studied, as well as the variation of heat transfer rate with sound source intensity at constant heat flux. Results show that convection heat transfer was remarkably enhanced due to disturbance and impingement by cavitation bubble. Among these cases tested, the maximum augmentation ratio of 3.95 was reached for acetone with a cluster of cavitation bubbles impinging perpendicularly on the tube surface.

关键词： acoustic cavitation heat transfer enhancement convection cavitation bubble.

Calibration and Experimental Research of a Multiple-wavelength Flame Temperature Instrumentation System

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Journal of Thermal Science 2004年第4期13卷 371-375页

作者： Zhihong Li Shi Liu Huaiping Mu Fan Jiang Jianmin Guo Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

This paper presents a study on a novel instrumentation system for the measurement of temperature distribution of combustion flames. This system operates upon the three-color principle combining advanced optical sensing and digital image processing techniques. It comprises an endoscope, a light splitter assembly, a CCD camera, a frame-grabber and associated software. This system was calibrated using a blackbody furnace as standard temperature source. The relationship between flame temperatures and grey-level of the images was established through image processing and function correlation. Experimental results obtained on a gas-fired combustion rig provide flame images and temperature distributions on three different wavelengths. Based on the flame temperature distribution the combustion conditions can be analyzed. Experimental results also reveal that this system is capable of online measurement of temperature distribution in a combustion zone. This system can potentially be applied to many areas such as power generation, metallurgy, chemical engineering. It is also a powerful tool for improving the control of combustion process. Keywords three-color method - flame monitor - temperature - imaging processing CLC number TK311

关键词： three-color method flame monitor temperature imaging processing

Green ICT Impact on Energy Conservation and Emission Reduction

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China Communications 2008年第3期5卷 79-84页

作者： Wu Hequan Chinese academy of Engineering, Beijing, 100088, China Chinese acad engn Beijing 100088 Peoples R China

The direct and indirect effect of ICT on energy conservation and emission reduction is described. The energy consumption per unit GDP in the ICT industry is lower than that in other industries. The application of ICT in such fi elds as industrial design, manufacturing, management, logistics, sales and service can be helpful for energy conservation and emission reduction in the industrial and transportations industry; however, the issue of energy waste and environmental pollution caused by voluminous deployment of ICT products should never be overlooked. This paper presents the lat- est development of communications products in energy conservation and exemplifi es the roles of ICT in energy conservation and consumption reduction. The issue of electromagnetic radiation of ICT products and the recycling and reuse of e-wastes are explored.

关键词： ICT energy conservation emission reduc-tion Green ICT

Experimental Study on Wavy-Flow Pneumatic Conveying in Horizontal Pipe

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Journal of Thermal Science 2002年第2期11卷 114-120页

作者： Hua Xu Shi Liu Haigang Wang Fan Jiang Chinese acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China

Low-velocity pneumatic conveying systems have been developed to meet the requirement of low operation costs and have been widely used in chemical and process industries. However, the understanding of the mechanism is limited. This paper reports an experimental study on a slug-flow pneumatic conveying. Electrical capacitance tomography has been used to visualize plug shape and identify the flow pattern. Comparison was made between the experimental data of pressure drop with existed models.

关键词： pneumatic conveying wavy flow pressure drop electrical capacitance tomography.