Table of Content

30 September 2011, Volume 45 Issue 09 Previous Issue    Next Issue

Metallography and Metallurgical Technology

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A Three-dimensional Stall Model for Vaneless Diffusers of  Centrifugal Compression System SHEN Feng-1, ZHU Xiao-Cheng-1, DU Chao-Hui-1, CHEN Hua-2 2011, 45 (09):  1251-1251.  Abstract ( 3534 )   Save A three-dimensional model was presented to study the occurrence of rotating waves in vaneless diffusers of centrifugal compressors. By solving 3D incompressible linearized Euler equations via finite difference method and the singular value decomposition (SVD) technique, the critical inlet flow angle and propagation speed of rotating stall in vaneless diffusers were predicted. The results show that both the critical inlet flow angle and the propagation speed are affected not only by the diffuser geometry, but also by the departure from axial uniform distribution of the undisturbed radial velocity at the diffuser inlet. The predictions of 3D model show a better agreement with experimental results than those of 2D model. References | Related Articles | Metrics

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Research on Non-contact Swirl Sucker Based on CFD and Orthogonal Test YE Qian, WU Qiong 2011, 45 (09):  1256-1262.  Abstract ( 3640 )   Save Computational fluid dynamics (CFD) was used to simulate the performance of a new kind of pneumatic levitation sucker (non-contact swirl sucker). Based on the existing structures, the improved program was proposed. The results of CFD simulation for improving structures show that in the case of little change in air consumption, suction has been significantly enhanced. That is much better than the performance of the original structure. Orthogonal test method was used to optimize the parameters of non-contact swirl sucker with the deflector body. The satisfied parameters are obtained. References | Related Articles | Metrics

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Dynamic Analysis and Simulation of a 6-Degree of Freedom Parallel Earthquake Simulator ZHANG Jian-Zheng, GAO Feng, ZHAO Xian-Chao, MA Chun-Xiang 2011, 45 (09):  1263-1268.  Abstract ( 3645 )   Save Based on Newton-Euler method, the research on the dynamics of a 6-PSS parallel earthquake simulator was presented. The relations of motion parameters between the platform and other poles were deduced. Newton-Euler equations were educed for every poles and the platform respectively with thinking about the effect of the gravity and inertia force of all components. After all of forces between poles and between platform and other poles being removed, equations for the inverse dynamics of the holistic parallel mechanism were established. According to the dynamic model, a numerical simulation was presented and the driving force emulational curves for different modes of vibration were obtained. The results show that not only the dynamic model is valid but also this earthquake simulator is suited to simulate seism. The dynamic model also has a potential application of accurate control to the parallel earthquake simulator. References | Related Articles | Metrics

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Analysis on Circumferential Clearance of Rzeppa Constant Velocity Joint HUANG Zhong-Ling-1, GUO Chang-Ning-1, SHI Bao-Shu-2 2011, 45 (09):  1269-1274.  Abstract ( 4563 )   Save Based on structure and motion forms of rzeppa constant velocity joint, the threedimensional model of circumferential clearance of elliptic section was established, and the formula of circumferential clearance angle (θ) at any swing angle and rotating angle was deduced, the changing law of θ with swing angle and rotating angle was obtained by using Matlab software. The results show that θ is related to the short and long half axle of the elliptical raceway, radius of steal ball, turning radius of steal ball, eccentricity, swing angle and rotating angle. The six fluctuations of θ lead to the vibration and noise during the travelling.   References | Related Articles | Metrics

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Estimation for Normal Parameters of Joint Surfaces Based on Fractal Theory YOU Jin-Min, CHEN Tian-Ning 2011, 45 (09):  1275-1280.  Abstract ( 3076 )   Save A new fractal model for the normal parameters of joint surfaces was established based on fractal contact theory. The model suggests that the values of normal contact parameters such as the contact stiffness and the contact damping can be estimated by obtaining the normal contact load, material properties of rough surfaces and fractal parameters. The varying laws of normal contact parameters were also simulated numerically. The research results indicate that the entire contact area of joint surfaces can be divided into the elastic and the plastic regions. And the small spots are in plastic contact whereas the large spots are in elastic contact. Besides, the relations between normal contact parameters of joint surfaces and fractal parameters are of strong nonlinearity. Moreover, the effects of normal load on contact stiffness are obvious. As the normal load is increased there is also a distinct increase in the behavior of normal contact stiffness. However, the normal load has less effect on the normal damping of joint surfaces. In addition, the extreme points in the varying curves might provide the reference for the optimization design of these contact parameters. References | Related Articles | Metrics

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Service Attribute Decision Making Based on Revised Importance Performance Analysis TAN Yuan-Ling, CHU Xue-Ning, ZHANG Zai-Fang 2011, 45 (09):  1281-1287.  Abstract ( 2983 )   Save In order to represent the individuation difference and subjective uncertainty in customer evaluation adequately, multigranularity and multisemantic fuzzy number which is translated into uniform decision information by conversion function was adopted to express service attribute’s performance value. Considering the affection to decision result arisen from the connection relations between importance degree of service attribute, analytic network process was adopted to identify the service attribute importance degree; consequently a revised importance performance analysis came into being to determine the priority in service attribute’s improvement effectively. A maintenance service of horizontal directional drilling machine was given to demonstrate the efficiency and feasibility of the revised method. The results show that the revised importance performance analysis is consistent with objective situation, which can be used to better guide business decisions. References | Related Articles | Metrics

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Topological Structure and Configurability of Process Networks YAN Dong-a, DONG Ming-b 2011, 45 (09):  1288-1293.  Abstract ( 3090 )   Save The machining process network of real industrial steam turbines was chosen to analyze common motif types of process couples, and to study the topological connectivity of the network in order to discover the configuration law of process couples. For connectivity of process network, based on complex network theory, the motif structures of the network were discovered from the microscope view, and its degree distribution features were analyzed from the macro one. The results are as follows: the complex process network is the diverse topology collection of simple motif types; its connectivity reveals the scalefree feature with the decaying power law, so only a few processes with large degree values hold many configuration relationships; and moreover, the connectivity shows disassortativity, so that a part of configuration relationships behaving randomly bears a weak configurability, but others with technology restriction reveal a strong one. The degree correlation coefficients proposed on the basis of disassortativity can be applied to evaluate the configurability of a process couple or whole process chain. References | Related Articles | Metrics

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Theoretical Analysis of Volume Speed-Regulating Circuit of Multi-Pump and Multi-Motor 2011, 45 (09):  1294-1298.  Abstract ( 3502 )   Save  This paper analyzed the traditional circuit of variable displacement pump or fixed displacement motor. On this basis, a new volume speed circuit which consists of multi-pump or multimotor was proposed. The paper also separately analyzed the operating principle and character of variable displacement pump or fixed displacement multi-motor and variable displacement multi-pump or fixed displacement multi-motor; the character curves were obtained. Compared with the traditional circuit of variable displacement pump or fixed displacement motor it is found that the new volume speed circuit can acquire multi-stage constant torque or multi-stage constant power regulation, which expands the range of speed. References | Related Articles | Metrics

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Effect of the Influence of Functional Connections in Mental Images on Design Cognition Process 2011, 45 (09):  1299-1303.  Abstract ( 2893 )   Save According to the semantic network theory, three theoretical hypotheses were presented on the influence of functional connections in mental images on design time, design quality, and creativity of design results. A series of adjustable seat conceptual design cognition experiments with 14 postgraduates of mechanical major were conducted to test the hypotheses based on protocol analysis. The results of MannWhitney nonparametric tests show that the more the functional connections among knowledge units in mental images are, the less design time it takes, the higher quality design it produces, and the more creative design it conceives. So all the hypotheses hold. References | Related Articles | Metrics

Automation Technique, Computer Technology

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Grid-Based Crashworthiness CAE System and Its Application WENG Yi-Liu, JIN Xian-Long 2011, 45 (09):  1304.  Abstract ( 2881 )   Save  Numerical analysis method has been the principal means for vehicle crashworthiness research in recent years. Based on grid technology and numerical analysis techniques, this paper proposed a grid middleware and a 4-layer grid architecture for vehicle crashworthiness study. The methodology for collaborative simulation and distributed data mining was also investigated. On the basis of the above achievements, a collaborative simulation system for crashworthiness simulation and data mining was developed. The system was further applied in a specific project rooted in vehicle industry and yielded a good result. This system  proved to be effective development tools for the web-based automotive design, optimization of matching design. References | Related Articles | Metrics

Metallography and Metallurgical Technology

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Preparation and Friction and Wear Behavior of Rare Earth Treated Carbon Nanotubes Self-assembled Composite Film SUN Zhi-Yong-1, CHENG Xian-Hua-1, 2 2011, 45 (09):  1310-1314.  Abstract ( 3813 )   Save Rare earth (RE) treated carbon nanotubes (CNTs) composite thin films were prepared on hydroxylated glass substrates by a selfassembling process from specially formulated solution. The contact angles of distilled water on the glass selfassembled films (SAMs) and the composite film were measured to compare the surface states. The resultant composite film was characterized by means of Xray photoelectron spectroscopy (XPS). The friction and wear properties of the films sliding were evaluated on a UMT2MT reciprocating friction and wear tester. The experimental results show that CNT composite films are deposited on oxidized APTESSAM. The friction coefficient of glass substrate is reduced from 0.70 to 0.13 after the formation of CNTsSAM on its surface. The preparation of rare earth treated carbon nanotubes selfassembled composite film via selfassembly method is feasible and provides test basis for the application of CNTsSAM in the field of tribology. References | Related Articles | Metrics

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Setup Planning Algorithm for ThinWalled Sleeve Part SUN Xi-Wu, CHU Xue-Ning, SU Yu-Liang, CHEN Dong-Ping, CHU De-Xin 2011, 45 (09):  1315-1321.  Abstract ( 3413 )   Save The part manufacturing model, setup and operation were developed to solve the setup planning of the thinwalled turning part. A mathematical model of setup planning was introduced based on discussions about machine types, tool approach directions and operation procedure constraints. The setup planning was divided into three subproblems to decrease the problem solution space according to grading for the thinwalled turning part. An algorithm based on rules, graph theory and clustering was introduced to determine setup planning procedure and operation groups in the process of solving the subproblems. A complete setup planning was put forward for the thinwalled turning part. Finally, an example of an aviation part was illustrated to prove the feasibility of the proposed model. References | Related Articles | Metrics

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Features Combined Classification of Cavitation in Waterjet Pumps DUAN Xiang-Yang, WANG Yong-Sheng, SU Yong-Sheng 2011, 45 (09):  1322-1326.  Abstract ( 3374 )   Save Onboard experiments were carried out when the waterjet pumps are working on the conditions of none cavitation zone, cavitation zone Ⅰand cavitation zone Ⅱ, acoustic and vibration signals were acquired respectively by hydrophones mounted in the inspection holes and acceleration transducers mounted on the case of the waterjet pumps. It showed that both of the second derivatives of the acoustic and vibration signals have notable differences before and after cavitation, and visible peak values appear in 8-25 kHz of acoustic signal and 3-12 kHz of vibration signal after cavitation. Cavitation feature sets were constituted based on the peak series of the second derivatives for features combined classification. The results show that the three types signals can be distinguished well by features combined classification, and the effect of multi-sensors features combined classification is better than that of single-sensor, especially the effect of multi-sensors features combined classification based on high order derivative  is more perfect. References | Related Articles | Metrics

General Industrial Technology

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The Preparation Technology and Forming Properties of WoodPlastic Composite Powder Used in Selective Laser Sintering GUO Yan-Ling-1, JIANG Kai-Yi-1, YU Zhi-Xiang-2, XIN Zong-Sheng-1, ZENG Wei-Liang-1 2011, 45 (09):  1327-1331.  Abstract ( 3169 )   Save This paper studied the prototyping technical principle of wood plastic composite based on selective laser sintering, and designed the formula of the wood plastic composite. And experiments were shown to verify the correctness. The results show that the prepared composite can meet the processing requirements of SLS, the shape precision of the formed parts is high, and the parts reach a certain mechanical index. Before post-processing the tensile strength is 14 kPa, the bonding strength is 475 kPa and the shock strength is 567 J/m2. References | Related Articles | Metrics

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Research on the Behavior of High-Strength Hollow Glass Particle Composite under Full Ocean Depth YAN Hui, GE Tong, ZHAO Min, CHEN Xian, LIU Jian-Min 2011, 45 (09):  1332-1335.  Abstract ( 3059 )   Save A full ocean depth simulation test was presented to study the behavior of high-strength hollow glass particle composite under full ocean depth. The paper discussed the effects of value of water pressure on the material with different densities,  hollow glass microsphere and hardener on water absorption and dimensional stability of the material. The results show that the water absorption rate is obviously influenced by the value of water pressure, the water absorption rate of the material under 121 MPa is almost doubled compared with 111 MPa, and under the same pressure, the material with higher density has lower water absorption rate. The dimensional stability of the material is very good, the maximal line shrink rate is only 0.51％ under 111 and 121 MPa static water pressure. References | Related Articles | Metrics

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Effect of Pulse Width and Mass Flux on Microscale Flow Boiling CHEN Gang, QUAN Xiao-Jun, ZHENG Ping 2011, 45 (09):  1336-1339.  Abstract ( 3788 )   Save The investigation on microscale flow boiling of subcooled water was carried out based on the microchip fabricated by MEMS technology. The effects of pulse width and mass flux on boiling inception were analyzed. A Pt microheater (140 μm×100 μm) was used in this experiment. Six pulse widths (0.05, 0.10, 0.20, 0.60, 1.00 and 2.00 ms) and five mass fluxes (45, 90, 135, 180 and 225 kg/(m3·s)) were chosen during experiment. It is found that either pulse width or mass flux has little effect on boiling inception time. An expression which for the transition heat flux of boiling regimes under different pulse width fits well with experimental data is obtained. A most effective pulse width is obtained through the analysis on nondimensional boiling inception time.   References | Related Articles | Metrics

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Effect of Hydrostatic Pressure on Acoustic Performance of Sound Absorption Coating TAO Meng-1, ZHUO Lin-Kai-2 2011, 45 (09):  1340-1344.  Abstract ( 3426 )   Save Based on the two-dimensional analytic model of sound absorption coating which contains cylindrical cavities, the effective impedance of the viscoelastic cylindrical tube was derived by considering the propagating characteristics of the lowestorder axisymmetric wave. The unit cell of sound absorption coating which contains a deformed cylindrical cavity could be approximated as the combination of several uniform cylindrical cavities, and the transmission line theory was applied to describe the unit cell so that the simplified calculation method of the acoustic performance of sound absorption coating was obtained. The finite element software was used to calculate the deformation of the unit cell under the hydrostatic pressure, and the effect of the hydrostatic pressure on the acoustic performance of sound absorption coating was evalu-ated by using the simplified calculation method. The results show that the hydrostatic pressure causes the decrease of the unit cell thickness and the cavity size, both alternations lead to the bad low-frequency sound absorption performance,  and the frequency of the peak absorption coefficient being shifted to the high frequency. References | Related Articles | Metrics

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Effect of the Performance of the G-M Cryocooler with Labyrinth Sealing Displacer HAO Xi-Huan, JU Yong-Lin 2011, 45 (09):  1345-1350.  Abstract ( 3144 )   Save The labyrinth sealing displacer was designed to improve the operating stability and cooling performance of the 10 K Gifford-McMahon (G-M) cryocoolers. The effects of the traditional piston-ring sealing and the labyrinth sealing on the cooling performance were experimentally compared. The effects of the displacer materials and charge pressures on the sealing performance were also tested. The displacer made of stainless steel has the same shrinkage as the piston cylinder at low temperatures and its sealing performance is superior to the displacer made of fiber-glass. The charge pressure has no obvious effect on the sealing performance, but the larger cooling capacity can be achieved at higher charge pressure. References | Related Articles | Metrics

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Effect of Wave Direction Angles on the Dynamical Amplification Factor of Selfelevating Platform HUANG Zhao-Yu-1, 2 , TANG Wen-Yong-1, WANG Yi-2, WANG Wen-Tao-2 2011, 45 (09):  1351-1354.  Abstract ( 3356 )   Save The dynamical amplification factors based on the hull displacement for different wave directions were computed using Stokes’ 5th order wave theory, which was implemented through the ocean engineering software SACS. Then the DAF values for different wave directions were compared, which were described and explained. Some useful conclusions are got: the DAF curves are very similar for different wave angels, the differences of structural displacement acceleration are attributed to the change of difference of hydrodynamic force, the dynamical amplitude is increased because of the superimposed effects of the 1st and 2nd hydrodynamic harmonics. References | Related Articles | Metrics

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Fault Diagnosis for Refrigeration Systems Based on Principal Component Analysis and Support Vector Machine HAN Hua-1, GU Bo-1, REN Neng-2 2011, 45 (09):  1355-1361.  Abstract ( 3734 )   Save Principal component analysis (PCA) was employed to make feature extraction from the vast data pool, and the PCA+SVM (support vector machine) model was established for the fault detection and diagnosis (FDD) of refrigeration systems. Considering that SVM can not be used to solve multiclass classification problems directly, several classical multiSVMs algorithms were analyzed and compared, and the “One vs others” algorithm was adopted. The hybrid PCASVM FDD model was presented and validated by the historical data from specially designed experiments. The results show that it can isolate normal from faulty modes (detection) and has a diagnostic rate of no less than 98.57%, which is better than the SVM model without PCA; model training is about 130—350 times faster than the latter; it also has better performance on dealing with small sample problem than BP neural network with higher diagnostic rate and much less training time (about 1/240). References | Related Articles | Metrics

Radiao Electronics, Telecommunication Technology

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Lifetime Analysis of LeadFree Ball Grid Array Solder Joints under Random Vibration WANG Wen, LIU Fang, YOU Ming-Yi, MENG Guang 2011, 45 (09):  1362-1367.  Abstract ( 3051 )   Save Four groups of random vibration tests of solder joints were conducted with different power spectral density (PSD) of input acceleration. Proportional hazards model (PHM) was used to evaluate the effect of PSD of input acceleration on the solder joints’ life span. The meantimetofailure (MTTF) and the failure probability density function (PDF) estimated from the PHM agree well with the experimental data, and this validates the effectiveness of the PHM. By the curve of the MTTF s, it can be observed that the MTTF<1 800 s when the amplitude of PSD was greater than 60 m2/s3, and this demonstrates that the lead-free solder joints are very sensitive to random vibration loading. Finally, the estimated lifetime of MTTF was integrated with the Miner’s law for cumulative damage model of lead-free solder joints. References | Related Articles | Metrics

General Industrial Technology

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Air-Side Heat Transfer Modeling Suitable for Fault Detection and Diagnosis of Refrigeration and Air-Conditioning Systems KANG Jia, HAN Hua, GU Bo, QIU Feng 2011, 45 (09):  1368-1373.  Abstract ( 3392 )   Save For fault detection and diagnosis (FDD), three different models to calculate airside heat transfer were analyzed, taking into account the influencing factors and the structures. Meanwhile, experiments were developed to validate and make comparison among the three models. The results show that Lin G G model is not suitable for the modeling applications in FDD because of its nonmonotonic characteristics, while the other two (J model and turbulence tube bundle model) are suitable with J model the most accurate. References | Related Articles | Metrics

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Fast Calculation Model of Thermodynamic and Transport Properties of R410a Refrigerant: Ⅰ. Equation for Saturation Curve HONG Ying-Chun, GU Bo, HAN Hua 2011, 45 (09):  1374-1378.  Abstract ( 4564 )   Save Based on the Martin-Hou equation of state, a fast calculation model for R410a thermodynamic and transport properties, covering saturation curve (139.00—343.32 K), was presented due to no need of iteration. This method can not only achieve the accuracy, but guarantee the calculation stability and high calculation speed of thermophysical and transport properties of R410a. The source data was calculated from REFPROP 7. The total mean relative error and maximum relative error for all fast calculation models are less than 1.174% and 13.218%, respectively. The comparison result shows that the calculation speed of the fast calculation model is two to four orders faster than those of REFPROP 7. References | Related Articles | Metrics

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Fast Calculation Model of Thermodynamic and Transport Properties of R410a Refrigerant：Ⅱ. Equation for Superheat Region HONG Ying-Chun, GU Bo, HAN Hua 2011, 45 (09):  1379-1383.  Abstract ( 4208 )   Save Based on the Martin-Hou equation of state, a fast calculation model for R410a thermodynamic and transport properties, covering superheat region(pressure:4—4 355 kPa, superheating of 0—100 K), was presented due to no need of iteration. This method can not only achieve the accuracy, but guarantee the calculation stability and high calculation speed of thermophysical and transport properties of R410a, and it is also convenient in cases of simulation of refrigeration system. The source data was calculated from REFPROP 7. The total mean relative error and maximum relative error for all fast calculation models are less than 1.24% and 14.30%, respectively. The comparison result shows that the calculation speed of the fast calculation model is two to four orders faster than those of REFPROP 7. References | Related Articles | Metrics

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Fast Calculation Model of Thermodynamic and Transport Properties of R410a Refrigerant：Ⅱ. Equation for Superheat Region HONG Ying-Chun, GU Bo, HAN Hua 2011, 45 (09):  1379-1383.  Abstract ( 2972 )   Save Based on the Martin-Hou equation of state, a fast calculation model for R410a thermodynamic and transport properties, covering superheat region(pressure:4—4 355 kPa, superheating of 0—100 K), was presented due to no need of iteration. This method can not only achieve the accuracy, but guarantee the calculation stability and high calculation speed of thermophysical and transport properties of R410a, and it is also convenient in cases of simulation of refrigeration system. The source data was calculated from REFPROP 7. The total mean relative error and maximum relative error for all fast calculation models are less than 1.24% and 14.30%, respectively. The comparison result shows that the calculation speed of the fast calculation model is two to four orders faster than those of REFPROP 7. References | Related Articles | Metrics

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A Correlation Model of Thermal Entrainment Factor for Air Curtain in Horizontal Display Cabinet YU Ke-Zhi-1, DING Guo-Liang-2, CHEN Tian-Ji-1 2011, 45 (09):  1384-1388.  Abstract ( 4144 )   Save From dimensionless transformation, the thermal entrainment factor (TEF) for air curtain in a horizontal display cabinet is dependent on four dimensionless numbers: Reynolds number indicating effect of air curtain supply parameters, Richardson number indicating effect of ambient parameter and two other dimensionless numbers indicating effect of air curtain geometry parameters. The correlation model of TEF for air curtain in a horizontal display cabinet was developed based on the computational fluid dynamics (CFD) simulation results, and the TEF calculated by the correlation model was compared with the measurement. The results show that the reliability validation of correlation model is good. The TEF of display cabinet predicted by the correlation model gives a maximum deviation of 11.7% and a mean deviation of -0.6% compared with the published experimental data. References | Related Articles | Metrics

Aeronautics & Astronautics

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Experiments on Adsorption Performance and Simulation on Freezing System for CaCl2-BaCl2-NH3 Two-Stage Adsorption WANG Jian, HU Yuan-Yang, WANG Li-Wei, WANG Ru-Zhu 2011, 45 (09):  1389-1394.  Abstract ( 3738 )   Save In order to achieve freezing condition under -15 °C while the heating source temperature is lower than 100 °C and the condensing temperature is higher than 30 °C, a CaCl2-BaCl2-NH3 adsorption refrigeration system was designed with two-stage desorption cycle. A series of experiments were performed on two-stage adsorption test unit in order to get the adsorption and desorption data of the composite absorbents, which are the mixture of salt chloride and expanded graphite. By fitting the data into adsorption and desorption curve, we set a mathematic model of the system by combining the adsorption and desorption equations and heat transfer equations of the system. The performance of the system was simulated and the results show that the system is able to use 85 °C heating source for the output of -15 °C freezing temperature, when the condensing temperature is 30 °C. The cooling capacity of the system simulated is 2.62 kW. References | Related Articles | Metrics

Hydraulic Engineering

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PIV Analysis of Inner Flow Field in 90° Bending Duct of Circular-Section with Fore-End Valve XIE Long-1, JIN Si-Yu-1, 2 , YU Jian-Guo-1, WANG Yu-Zhang-1 2011, 45 (09):  1395-1399.  Abstract ( 4214 )   Save Through the established recirculation water channel, the inner flow field in 90° bending duct of circular-section with a fore-end valve was measured by particle image velocimetry (PIV). Characteristics of the flow were obtained through correlation analysis of the massive consecutive high-resolution transient velocity maps, including time-averaged velocity field, streamline pattern and vorticity distributions. Through comparative analysis of the time-averaged velocity field: it is concluded that there exist apparent high-speed and lowspeed regions in the bend part; a vortex emerges on specific conditions; the features of the flow field vary considerably along with the diversity of valve opening magnitude, flow rate and section location. References | Related Articles | Metrics

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Experimental Study on Influencing Factors and Their Effects on No-Vent Fills WANG Cai-Li, DENG Dong, LI Yang, WANG Rong-Shun 2011, 45 (09):  1400-1405.  Abstract ( 3624 )   Save A test rig of no-vent fills for cryogen was set up to study the feasibility and influencing factors of no-vent fills. Five main parameters, including incoming liquid temperature, inflow rate, initial wall temperature, outlet height and filling configurations are changed to find out their effects on the performance of no-vent fills. It is experimentally shown that the pressure in the receiver tanks will increase if either the incoming liquid temperature or the initial wall temperature increases. Inflow rate impacts mostly on the filling time. The filling outlets’ height and configuration make combined influence on the performance of novent fills. References | Related Articles | Metrics

Chemical Engineering

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Dispersion Characterization of PTFE Composites Filled with Different Nano-particles HE Chun-Xia, LU De-Rong, XIAO Sheng-Ming 2011, 45 (09):  1411-1415.  Abstract ( 4066 )   Save The sweep electron microscopy (SEM) image was processed and segmented to nano Si3N4, SiC, and AlNmodified PTFE composites. Agglomeration degree and dispersed uniformity of the nano-particles in the image were quantatively segmented using particle dispersion method. The results show that the dispersed uniformity of these three nano-particle decreases as follows: nanoSiC, and nanoSi3N4, nano-AlN. Under the condition of 7% of nano-Si3N4 and nano-SiC and 5% of nano-AlN, the dispersed uniformity in PTFE is better. By processing coupling agent NDZ, the agglomeration degree of nano-particles in PTFE will decrease, the dispersed formity of nanoSi3N4 and nano-SiC in PTFE will be improved, but the dispersed formity of nano-AlN in PTFE will decrease. References | Related Articles | Metrics

Others

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Problems and Solutions of the Work of Applying for State Science and Technology Award in Research Universities HE Xian-Mei 2011, 45 (09):  1416-1419.  Abstract ( 3362 )   Save This paper analyzed the importance of applying for state science and technology award in research universities. As a result of current science and technology review mechanism, there exist errors in recognition and anomie in behavior in research universities’ applying for state science and technology award. The paper suggests research universities should enhance the normalization of their applying activities. Therefore, it should pay more attention to pursuing academic achievement and strengthening process management, in order to  stop all academic corruption. References | Related Articles | Metrics

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Research on Scientific Innovative Management Mode Based on Closed-Loop Lifecycle Model in Institutions of Higher Education DAI Zhi- Hua-a, b 2011, 45 (09):  1420-1424.  Abstract ( 3840 )   Save There are many similarities in theory and process between scientific research projects management in institutions of higher education and product lifecycle management, while the closedloop product lifecycle management has good competence. After the summary and analysis of the current problems of the traditional scientific research management mode, this paper described the ideas and process of the design of scientific research innovative management mode based on closedloop lifecycle model in institutions of higher education. The practices of near ten “985 project” universities show that the scientific research innovative management mode can improve scientific research management performance, and the mode deserves being popularized in others institutions of higher education. References | Related Articles | Metrics

Hydraulic Engineering

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Simulation Study on Flow Control Device Based on AMESIM WANG Cheng-Yu-1, 2 , CHANG Han-Bao-1, HONG Zhe-2, XU Hai-Cheng-1 2011, 45 (09):  14006-1410.  Abstract ( 4173 )   Save A new flow controller which is applied to high pressure common-rail system was introduced. The simulation model of flow controller was established by AMESIM. The working process of flow controller was analyzed. The simulation results indicate that the flow controller can satisfy the requirements of diesel engines and the common rail pressure can be controlled with high precision and better flexibility. References | Related Articles | Metrics