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2010 International Conference on Mechanic Automation and Control engineering, MACE2010

作者： Zhao, Libo Zhang, Guiming Jiang, Zhuangde Liu, Zhigang State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an China State Key Lab. of Multiple Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9781424477388

A MEMS (Micro Electro-mechanical System) resonator-type viscosity sensor with range from 0 to 1 mPa·s was presented with good frequency response and high sensitivity. Its sensitive chip with a triangular cantilever structure was investigated. This paper studied the operating principle of the MEMS resonator-type viscosity sensor. The natural frequency of the sensitive chip was deduced with its structure size in theory, which was validated with ANSYS finite element software. The modal analysis and harmonic response analysis for the sensitive chip with triangular cantilever structure were performed to determine the resonant mode of the MEMS viscosity sensor. Finally, the layout and fabrication processes of the sensitive chip of the MEMS resonator-type viscosity sensor were designed and studied. The sensitive chip with small size, high sensitivity and high temperature resistance was fabricated with MEMS technology on SOI (Silicon on Insulator) monocrystalline in order to achieve real-time on-line measurement of fluid viscosity. ©2010 IEEE.

关键词： Natural frequencies

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A MEMS density sensor based on mircro-rectangular cantilever

A MEMS density sensor based on mircro-rectangular cantilever

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2010 International Conference on Mechanic Automation and Control engineering, MACE2010

作者： Zhao, Libo Huang, Enze Jiang, Zhuangde Liu, Zhigang State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an China State Key Lab. of Multiple Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9781424477388

A rectangle cantilever-type micro density sensor was researched based on MEMS (Micro Electro-mechanical System) technology. A Ti-Pt-Au coil and a Wheatstone full bridge were made on the top of the rectangle cantilever-type sensitive chip. The sensitive chip was placed in uniform strong magnetic field. The resonant frequency of the sensitive chip was changed with the change of the AC current's frequency. The resonant frequency of rectangle cantilever could be measured through the Wheatstone full bridge circuit and lock-in amplifier, and then the fluid density associated with the resonant frequency of the sensitive chip could be calculated. The static analysis, modal analysis, a first-order and third-order harmonic response analysis of the rectangle cantilever were performed with ANSYS software. The best locations of the four force-sensitive resistor of Wheatstone bridge were studied. ©2010 IEEE.

关键词： Natural frequencies

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On Dynamic Behavior of Triangular Shaped Cantilevers in MEMS Sensors: Effect of Curvature

On Dynamic Behavior of Triangular Shaped Cantilevers in MEMS...

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2010 10th IEEE International Conference on Solid-state and Integrated Circuit Technology(第十届固态和集成电路技术国际会议 ICSICT-2010)

作者： Guo-Ying Yuan En-Ze Huang Gui-Ming Zhang Zhuang-De Jiang Li-Bo Zhao Yong Li Zhi-Gang Liu State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an 710049 State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an 710049 State Key Laboratory of Tribology Tsinghua University Beijing 100084 China State Key Lab of Multiple Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

ISBN: (纸本)9781424457977

A study on the effect of curvature of triangular shaped cantilevers in MEMS sensors was presented. 3-D models were performed by using the SolidWorks software. And modal analysis and harmonic response analysis were carried out on different types of geometrically configured triangular shaped cantilevers using ANSYS software. The results included the variation of natural frequencies of cantilevers and maximum equivalent von mises strain on the cantilevers with respect to radius of curvature of triangular shaped cantilevers. According to the finite element analysis results, the curvature did affect dynamic behavior of triangular shaped cantilevers in MEMS sensors. Usually, the curvature is induced by the surface stress due to microprocessing or any change of temperature, etc. Therefore, in order to achieve a steady state of strain for the MEMS sensors, it's better to eliminate the surface stress and make the cantilever transform from a curved cantilever to a straight cantilever.

关键词： CANTILEVER Curvature Surface stress Triangular Microelectromechanical systems Sensors Microtechnology Response analysis

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Research on the flow Pattern of Bubble Plume in an Aeration Tank

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AIP Conference Proceedings 2010年第1期1207卷 646-652页

作者： W. H. Liu T. Wan W. Cheng Yuichi Murai aKey Laboratory of Northwest Water Resources and Environmental Ecology of Education Ministry Xi’an University of Technology Xi’an 710048 China bState Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710048 China cDivision of Energy and Environmental System Hokkaido University Sapporo Japan

The flow pattern of gas‐liquid two‐phase flow in an aeration tank is of critical effect upon mass transfer by the convection. Bubble plume provides unsteadily fluctuating two‐phase flow during the aeration. This paper the study on the unsteady structure of bubble plume is dealt with from experiment. The time‐serial bubble plume images of different cases in tank have been analyzed. The RCC‐PIV has been employed to calculate the velocities in those cases, and then the time‐serial vortex, the total turbulence intensity, the time‐serial streamline are obtained. It has been shown that the aspect ratio and void fraction are the dominant factors influencing the unsteady structure of bubble plume. When the aspect ratio is unity and the void fraction gets higher, the bubble plume has symmetrical vortex structure and longest residence time, which is beneficial for optimizing the aeration system and enhancing the applied range of bubble plume.

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Experimental study on pressure and temperature distributions for low mass flux steam jet in subcooled water

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Science China(Technological Sciences) 2009年第6期52卷 1493-1501页

作者： JunJie Yan XinZhuang Wu DaoTong Chong State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710049 China

A low mass flux steam jet in subcooled water was experimentally *** transition of flow pattern from stable jet to condensation oscillation was observed at relatively high water *** axial total pressures,the axial and radial temperature distributions were measured in the jet *** results indicated that the pressure and temperature distributions were mainly influenced by the water *** correlations corrected with water temperature were given to predict the dimen-sionless axial pressure peak distance and axial temperature distributions in the jet region,the results showed a good agreement between the predictions and ***,the self-similarity property of the radial temperature was obtained,which agreed well with Gauss *** present work,all the dimensionless properties were mainly dependent on the water temperature but weakly on the nozzle size under a certain steam mass flux.

关键词： dimensionless self-similarity steam jet condensation temperature distribution total pressure

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An Efficient and Stable Ionic Liquid System for Synthesis of Ethylene Glycol via Hydrolysis of Ethylene Carbonate

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Chinese Journal of Chemical engineering 2010年第6期18卷 962-966页

作者： MENG Zhenying SUN Jian WANG Jinquan ZHANG Jianxin FU Zengzeng CHENG Weiguo ZHANG Xiangping State Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100049 China College of Chemistry and Chemical Engineering Henan Universitv Kaifeng 475001 China School of Chemical and Environmental Engineering China University of Mining & Technology (Beijing) Beijing 100083 China

An ionic liquid system of [Bmim]X/[Bmim]OH(X Cl,BF4,and PF6,) was developed for the hydroly-sis of ethylene carbonate to ethylene glycol. The important parameters,such as the variety of ionic liquids,molar ratio of [Bmim]X to [Bmim]OH,amount of ionic liquid,molar ratio of water to ethylene carbonate,reaction tem-perature,pressure and reaction time,were investigated systematically. Excellent yield(>93%) and high selectivity(99.5%) of ethylene glycol were achieved. Under the optimum reaction conditions,the ionic liquid system could be reused at least five times and the selectivity of ethylene glycol remained higher than 99.5%.

关键词： ethylene carbonate ethylene glycol hydrolysis ionic liquids catalysis

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The 6th International Symposium on multiphase flow, Heat Mass Transfer and Energy Conversion (ISMF2009)

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International Journal of Hydrogen Energy 2010年第13期35卷 7027-7027页

作者： Liejin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University China

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Numerical simulation on forced convection heat transfer in porous media using Gibson‐Ashby constitutive model

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AIP Conference Proceedings 2010年第1期1207卷

作者： J. X. Wang P. Y. Jia Y. S. Wang L. Jiang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University China

In this article, using Gibson‐Ashby constitutive model, we suggest a new method for numerical investigation of forced convection heat transfer in porous foam metal, and try to consolidate the study for mechanical property and that for thermal characteristic. By available experimental data, we simulated to two cases, namely as the transfer in porous media for diameter is 0.6 mm and porosity is 0.402, and for diameter is 1.6 mm and porosity is 0.462. The result, from our constitutive model for single forced convection heat transfer, corresponds well with the experimental data. As for pressure drop prediction in porous is in good agreement with experiment, and the error is only 5% to 10%, but for transfer is less accurate, the error is about 20%, which is acceptable in practice. So it is done that constitutive model is used to simulate the transfer property.

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Measurement of laminar burning velocities and analysis of flame stabilities for hydrogen-air-diluent premixed mixtures

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Chinese Science Bulletin 2009年第5期54卷 846-857页

作者： HU ErJiang HUANG ZuoHua HE JiaJia JIN Chun MIAO HaiYan WANG XiBin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were meas-ured at different equivalence ratios (0.4―1.5), different diluents (N2, CO2 and 15%CO2+85%N2) and di-lution ratios (0, 0.05, 0.10 and 0.15) by using the outwardly expanding flame. The influences of flame stretch rate on the flame propagation characteristics were analyzed. The results show that both the laminar burning velocities and the Markstein lengths of the hydrogen-air-diluent mixtures decrease with the increase of dilution ratio. The decrease in Markstein lengths means that adding diluents into the hydrogen-air mixtures will decrease the diffusional-thermal instability of the flame front. For a specified dilution ratio, the laminar burning velocities give their maximum values at an equivalence ratio of 1.8. The Markstein lengths increase with the increase of the equivalence ratio monotonously regardless of the diluents. The study shows that CO2 as the diluent has a greater impact on the laminar flame speed and the flame front stability than N2 as the diluent.

关键词：氢气空气混合火焰特性燃烧速度稳定性

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A numerical model of thermal analysis for woven wire screen matrix heat exchanger

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Cryogenics 2009年第9期49卷 482-489页

作者： Shuangtao, Chen Yu, Hou Hongli, Zhao Lan, Xi State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Woven wire screen matrix heat exchanger (WSMHE) is a kind of compact, light-weight and high-efficiency matrix heat exchanger (MHE) for cryogenic applications. This paper presented a numerical model for the design and thermal analysis of WSMHE. The influence of wall thermal resistance, axial conduction, parasitic heat load and properties variation was taken into account, which is neglected in the traditional effectiveness-NTU method but important for compact cryogenic heat exchangers. The proposed numerical method is verified by effectiveness-NTU method under specific conditions, then it is tested according to experiment data, and a well agreement was obtained. Based on this model, a detailed analysis was performed on WSMHEs. The analysis results show that the axial conduction might result in evident decrease of effectiveness at low flow rate region;the effectiveness of WSMHEs with large flow rate could be remarkably enhanced by increasing its length;the influence of parasitic heat load varied little throughout of the flow rate region. Furthermore, the numerical model presented in this paper can be developed to the design and thermal analysis of small partition wall type heat exchangers. © 2009 Elsevier Ltd. All rights reserved.

关键词： Thermoanalysis

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