Table of Content

30 March 2012, Volume 46 Issue 03 Previous Issue    Next Issue

General Industrial Technology

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Modeling and Analysis of Rope Transverse Vibration for Flexible Hoisting Systems with TimeVarying Length BAO Ji-Hu-a, ZHANG Peng-a, b , ZHU Chang-Ming-b 2012, 46 (03):  341-345.  Abstract ( 3668 )   Save Transverse vibration of rope with timevarying length was investigated considering the continuum medium mechanics and the effect of the geometrically non-linear kinematics of deformation. The governing equations were developed employing the Hamiltons principle. The Galerkins method is used to discretize the governing equations. The motions of traction elevator hoisting systems were illustrated to evaluate the proposed mathematical models and solution method. The results of simulation show that the modeling methods considering the continuum medium mechanics can well represent the transverse vibration of hoisting rope systems with timevarying length.   References | Related Articles | Metrics

Communication and Transportation

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Optimization of Suspension Parameters Based on Vehicle-Track Coupled Model for a Special Railway Vehicle LI Xiao-Wei-1, ZHANG Jian-Wu-1, LU Tong-Li-1, XUE Lin-2 2012, 46 (03):  346-351.  Abstract ( 2742 )   Save Based on the vehicletrack coupled dynamics, the vehicletrack coupled model for the roadrail fire fighting vehicle moving on the track was established and was compared with the traditional railway vehicle model. For the validation of the two models, field experiments were made. The comparisons between the experimental test results and numeral simulation results indicate that the vehicletrack coupled model is better in accordance with the reality than the traditional railway vehicle model. Based on the vehicletrack model, the unified objective function method was used for the optimization of suspension parameters. The optimization results indicate that rootmeansquare values of car body acceleration, dynamic travel of secondary suspension and wheelrail force are reduced by 626%, 542% and 681%, respectively. Consequently, the riding quality is significantly improved, the dynamic travel of secondary suspension is greatly shortened, and the influence of wheelrail dynamic interactions on the damage and deform of track structures is remarkably decreased.   References | Related Articles | Metrics

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Study on Dynamic Response of SWATH Structure Subjected to Wave Loads and Slamming LoadsAs XIA Qi-Qiang, CHEN Zhi-Jian 2012, 46 (03):  352-357.  Abstract ( 4056 )   Save the particular structure for small waterplane area twin hull(SWATH), considering the timevarying characteristics and nonuniformity distribution of slamming load, formula of slamming load varied with space and time was deduced based on the theory of plat slamming. The directly loading technology that can realtime simulate waves was applied. Then an analysis of structure vibration response characteristics of SWATH subjected to wave loads and slamming loads was conducted, and the discussion of the slamming effect on hull strength was performed. The results show that there are some particular response models under combined loads. The effect induced by combined loads actions is not twonodal vibration like monohull, but transverse bending vibration of cross structure. Combined loads actions threaten the strength of wetdeck and stanchion severely. Slamming contributes to the structure vibration response significantly and influences the overall strength and deformation.   References | Related Articles | Metrics

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Modeling of Underwater Vehicles’ Planar Maneuvering Motion Based on Support Vector Machines XU Feng-a, ZOU Zao-Jian-a, b , SONG Xin-a 2012, 46 (03):  358-362.  Abstract ( 3226 )   Save At first, Kalman filter was adopted for data preprocessing of underwater vehicle’s simulation test. Then, least square support vector machines was applied to identifying the coefficients in the equations of planar maneuvering motion of underwater vehicles. The identification results were compared with those by using traditional least square method. It proves that the least square support vector machines is more effective. References | Related Articles | Metrics

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Fatigue Life Analysis Methods for Pump Tower of  Liquefied Natural Gas Carrier under Sloshing Load ZHANG Ai-Qing, XUE Hong-Xiang, TANG Wen-Yong 2012, 46 (03):  363-367.  Abstract ( 3287 )   Save This paper mainly researched on the pump tower structure fatigue life under sloshing loads in liquefied natural gas carrier. The motion of the hull is calculated using the dynamic load method. Based on the seakeeping results, the critical sloshing movement of the ship is selected according to ABS rules. The sloshing load is obtained using Morison formula based on the results of velocity and acceleration calculated by 2D sloshing program. Fatigue life of the pump tower is predicted using cumulative fatigue damage theory and the relation of fatigue damage degree to loading level is concluded.   References | Related Articles | Metrics

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Mid-ship Section Structural Design and Optimization Based on Knowledge Based Engineering CUI Jin-Ju, WANG De-Yu, XIA Li-Juan, MA Chong 2012, 46 (03):  368-373.  Abstract ( 4044 )   Save As an important target of containership, the midship section can well reflect the transportation ability and containers arrangement, so it has always attracted designers attention. This paper studied the design, optimization and 3 D modeling of midship section based on Visual Basic and Access. The arrangement of the new ship can be got by topology of the motherships . On the basis of structural information of mother ships, the structural information of new ship can by got by interpolation method according to rules formulations, then the genetic algorithm is adopted for optimization of key structures and it converges well. Compared with the design obtained by Rules method, the one by Interpolation method considers both the rules and design experience of experts, so it is more reasonable. Besides, 3D model is built in Tribon by Python program, which enhances manmachine interaction and makes the result easy for designers to modify. References | Related Articles | Metrics

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Study on EnergySaving Rudder Bulb Fin Combination Based on Surface Panel Method LIU Ye-Bao, SU Yu-Min, SHEN Hai-Long, JU Lei 2012, 46 (03):  374-378.  Abstract ( 4268 )   Save Rudderbulbfin is a kind of simple combined energysaving device. According to the method of propellerrudder system performance calculation, the steady interference between propeller and rudderbulbfin system in uniform flow was predicted by potential based surface panel method. The energysaving effect of rudder with bulbfin was compared with common rudder and rudder with bulb. Changing dimensions, the principal parameters (bulb size, fin size and installation angle) that affect energysaving effect was studied. The theoretical studies show that the energysaving effect of rudderbulbfin is better than that of rudderbulb and the design of rudderbulbfin has optimal bulb size, fin size and installation angle.   References | Related Articles | Metrics

Physics

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Simulation of Ship Motions Coupled with Tank Sloshing in Time Domain LI Yu-Long-1, ZHU Ren-Chuan-1, MIAO Guo-Ping-1, FAN Ju-1, FAN She-Ming-2 2012, 46 (03):  379-384.  Abstract ( 2778 )   Save Tank sloshing in ship cargo is excited by ship motions, in the meantime the sloshing flow induces impact load on tank wall, then affects the ship motion. Time domain ship motion was solved by using strip method and an impulse response function method based on the potential flow theory. Viscous flow theory was employed to simulate the nonlinear tank sloshing. Then the ship motion coupled with tank sloshing was established that the interactions of wave, ship body and tank sloshing are completely taken into considerations. This method has quite high efficiency for it takes advantage of potential flow theory for outer flow field and viscous flow theory for inside tank sloshing respectively. The numerical simulation and experimental studies indicate that the numerical results of ship motion coupled with tank sloshing can clearly shows the coupling effect of tank sloshing on the ship global motion. The results of the ship motion RAO of both computational and experiment ones are in good agreement.   References | Related Articles | Metrics

Aeronautics & Astronautics

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Ship Type Selection Based on Group Decision-Making with Multi-objects HOU Yuan-Hang, HU Yu-Long, WANG Wen-Quan, GUO Chun-Yu, WANG Chao 2012, 46 (03):  385-389.  Abstract ( 3314 )   Save Selection of shiptypes based on PSO group decisionmaking method with multiobjects was researched. First, at the foundation of multiobjects decisionmaking method which utilizes weighting distance to ensure the consistency of decision result, a new multischeme, multiobject group decisionmaking method was proposed. Then the individual evaluation value was adjusted by PSO, making the decision result keep the initial predilection of every expert and the fine consistency of interestrelevancies. And the new method was introduced to the process of shiptypes’ optimizechoice, then to determine the important factors and their weights, a series of shiptypes was generated by equality design, and numbers of experts were invited to make a strategic decision for achieving the decision result of best shiptype. This decision method offers a new simple and efficient avenue to optimizechoice of the shiptypes with high reliability.   References | Related Articles | Metrics

Communication and Transportation

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A Continuous Underwater Geomagnetic Localization Algorithm Based on Magnetic Moment HUANG Yu-a, b , HAO Yan-Ling-b 2012, 46 (03):  390-393.  Abstract ( 2879 )   Save Because magnetic dipole field is mixed with geomagnetic field, a geomagnetic localization method aided by vehicle draft depth was put forward to solve difficult acquirement of magnetic field magnitude, where the vertical position of vehicle relative to target can be calculated by two measurements of draft depth and magnetic gradient. The shortage of vehicle moving in vertical direction endlessly for continuous localization can be solved by a localization method using magnetic moment of the target, where the position of vehicle can be calculated by a nonlinear equation with position parameter composed of known magnetic moment and magnetic gradients. The concrete steps of continuous localization algorithm were given, and the numerical simulations prove the feasibility and higher precision of the localization algorithm.   References | Related Articles | Metrics

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Longitudinal Ultimate Strength of Composite Ship Hull Considering Delamination Damage Mode ZHANG Wei-1, PU Ying-Chao-2, TANG Wen-Yong-1, ZHANG Sheng-Kun-1 2012, 46 (03):  394-397.  Abstract ( 3836 )   Save Using 3D Hashin damage rules and the corresponding property degradation rules, the ultimate sagging and hogging longitudinal strength of a composite ship hull was analyzed considering the delamination damage mode based on the stress criteria of delamination. Then the degradation factor was presented which is used to predict the longitudinal strength of composite ship considering the delamination damage mode from the calculation of longitudinal strength of composite ship without considering the delamination damage model.   References | Related Articles | Metrics

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Application of Particle Swarm Optimization Theory in Skew Distribution of Highly Skewed Propeller WANG Chao-1, 2 , XIONG Ying-2, HE Miao-1, HUANG Sheng-1 2012, 46 (03):  398-403.  Abstract ( 3250 )   Save In order to design a more reasonable skew distribution of propeller section, the new particle swarm optimization (PSO) arithmetic of the intelligent optimized field combined with panel method was adopted to do the optimization design of the propeller’s skew distribution. The mathematical model and main process of the PSO arithmetic in the optimization design of the skew distribution were given, moreover the validity calculation to the propeller of HSP was did. The convergence of unsteady thrust coefficient’s 2ed amplitude and the skew distribution along with iterative times in two different rake modes was taken. At the same time, the change law of the key blade’s unsteady thrust coefficient along with iterative times in one circuit was also obtained. The results show that the unsteady coefficient fluctuation of the optimization propeller has a little reduction compared with the prototype. So the propeller’s performance can be improved through the optimization of skew in unsteady field and the feasibility of PSO method in propeller’s skew optimization is validated. References | Related Articles | Metrics

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Research on the Cavitation Identification Experimentation of Marine Waterjet SU Yong-Sheng, WANG Yong-Sheng, DUAN Xiang-Yang 2012, 46 (03):  404-409.  Abstract ( 2940 )   Save According to cavitation feature, the method of distinguishing cavitation characteristic frequency band was posed by using higher order derivative. The shell of waterjet pump vibration and inlet underwater acoustic were first calculated by higher order derivative, and then normalized with the root mean square (RMS). After filtering by cavitation characteristic frequency band, a local maximum with amplitude over a predefining threshold was picked up. The mean, root mean square, variance, skewness and kurtosis as the support vector machine classification input can realize classification diagnosis of six kind of marine waterjet cavitation states. Compared with identification result of back propagation（BP）and radial basic function（RBF）neural networks, the classification precision of least squares support vector classification(LSSVC) is more higher and the program runtime is more shorter. References | Related Articles | Metrics

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Determination of Propeller Cavitation Initial Inception and Numerical Analysis of the Inception Bucket YANG Qiong-Fang-a, WANG Yong-Sheng-a, ZHANG Zhi-Hong-b 2012, 46 (03):  410-416.  Abstract ( 3818 )   Save To apply the cavitation multiphase simulation for propeller cavitation inception and inception bucket prediction, the improved Sauer cavitation model and modified shear stress transport turbulence model were used to predict the NSRDC 4381 propellers back and face sheet cavitation inception, tip vortex cavitation inception and inception bucket bottom line characteristics. A rule to determine the cavitation inception was presented printed as ‘when σ>σi, the pressure coefficient of the tip blade section is unchangeable and its application region on the bucket was limited also. Based on it, the inception bucket was partitioned more nicely from traditional three regions to five at last so to depict the blade cavitation stage under different conditions more precisely. The results show that, under design and nondesign conditions, the predicted inception cavitation indexes of the back and faces blade section all agree well with the experiment. The simulated tip vortex cavitation inception represents the phenomenon of local tip vortex and leading edge tip vortex combination, and verifies the reasonableness of using the sheet cavitation inception curves of 07 R section on the back and 04 R section on the face to stand for the back and faces visual tip vortex inception respectively. The determination rule is valid for both back and face sheet cavitation region up the bottom line on the bucket. The region under the bottom line on the bucket can be partitioned as back sheet cavitation lying 03 R to tip on the blade surface and back and face sheet cavitation existing simultaneously in addition, so to sever the engineering better for using the five regions to depict the propeller cavitation and calculate the cavitation ship speed. References | Related Articles | Metrics

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Testing Method Study of Nonlinearity Characteristic for Pentamarans Motion in Waves CHEN Zhen 2012, 46 (03):  417-422.  Abstract ( 3492 )   Save The nature of pentamarans motion time series in waves was studied by surrogate data method. The motion response of three types of pentamarans in different sea state was predicted theoretically and the surrogate data were generated by the modified Fourier transform. At 005 significant levels, the nature of pentamarans motion time series was identified based on the testing statistics. The results indicate that the nature of motion response system does not change while four sponsons are arranged at the front and after side of the main hull body, and the surrogate data method can distinguish the system nature of pentamarans motion in random waves and also be fit for the identification of motion and wave load response system of ship and offshore structures.   References | Related Articles | Metrics

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Research on Minimum Additional Drag and Hydrodynamic Moment of Locked Controllable Pitch Propeller DING Jiang-Ming, WANG Yong-Sheng, HUANG Bin 2012, 46 (03):  423-429.  Abstract ( 3602 )   Save The optimal pitch of a locked controllable pitch propeller corresponding to minimal additional drag and minimal hydrodynamic moment was investigated by means of computational fluid dynamics for a ship that is propelled by part of propellers. A typical fiveblade controllable pitch propeller was calculated numerically to gain the characteristics of additional drag and hydrodynamic moment as functions of its pitch and advance velocity. The numerical calculations are based on finite volume method. The RANS equations of the 3D incompressible viscous flows are solved iteratively to simulate the flow behavior around the propeller. The calculation results show: ① The additional drag of the locked propeller is maximal when the propeller is set on maximal ahead pitch, which accounts for about 80% of the hull resistance at the same speed. The value of hydrodynamic moment also reaches maximum; ②The additional drag of the locked propeller is minimal when the propeller is set on maximal astern pitch, which accounts for about 50% of the hull resistance at the same speed. The hydrodynamic moment decrease markedly compared with the maximal ahead pitch; ③At zero pitch the additional drag lies between maximal ahead pitch and maximal astern pitch, and the hydrodynamic moment is very small which comes close to zero. These conclusions are helpful for marine engineers not only to determine joint control curve of the propulsion plant for the operating condition that the ship is propelled by part of propellers, but also to design the shaft brake rightly. References | Related Articles | Metrics

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Uncertainty Analysis in CFD for Flow Simulation Around Ship Using RANS and DES YANG Chun-Lei, ZHU Ren-Chuan, MIAO Guo-Ping, FAN Ju 2012, 46 (03):  430-435.  Abstract ( 3245 )   Save Procedures for uncertainty analysis in CFD recommended by the ITTC (International Towing Tank Conference) have been used widely among methods of error estimate and credibility assessment in the field of ship. The method includes verification and validation which qualify the numerical and modeling uncertainty. Following the procedures, the results of uncertainty analysis for resistance and wave profile which are computed by RANS and DES methods (detached eddy simulation) was verified and validated. Numerical verification studies in grid convergence were performed using three grids with grid refinement ratio 42. The uncertainty results will lay the foundation for the development of CFD uncertainty analysis. The work demonstrates the usefulness of the proposed verification and validation procedures and establishes the levels of verification and validation of the simulation results in two different mathematical models.   References | Related Articles | Metrics

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Dynamic OD Matrix Estimation Model of Urban Network DIAO Yang-a, JUAN Zhi-Cai-a, NI An-Ning-b 2012, 46 (03):  436-440.  Abstract ( 5046 )   Save Realtime dynamic OD matrix is an important input for dynamic traffic assignment system. This paper built a new statespace model whose measurement equation will take the interaction detection data into account, and proposed a onestep prediction Kalmanfiltering model to achieve this target. The case study shows that including the interaction data into the measurement equation will give a more accurate estimation and prediction and a simulationbased assignment matrix will give a more accurate reflection on how many volumes are detected by certain facility.   References | Related Articles | Metrics

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Experimental Study on the Effect of Longitudinal Crack on Reinforced Concrete Tunnel Lining LIU Xue-Zeng-a, BAO Hao-杉a, ZHOU Min-b 2012, 46 (03):  441-445.  Abstract ( 3014 )   Save Based on the loadstructure model,the structure test of reinforced concrete lining was done to establish the calculation model of reinforced concrete lining with crack. The relation curve of longitudinal crack depth and structure rotational stiffness was obtained through the analysis of deformation and crack development of reinforeced concrete lining in loading process. Exponential function could describe the curve of rapid change phase and stable phase, while parabola function could describe the curve of the accelerated change phase. A calculation model of reinforced concrete lining with one crack was proposed, and the crack was simulated by the connected spring whose parameters are determined through the results of lining structure test and theoretical analysis. The calculated safety factor can be used to evaluate the necessity of the concrete linings further strengthening. The proposed model has guiding significance to practical tunnel engineering. References | Related Articles | Metrics

Astronomy,Geoscience

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Research on Attitude Measuring Method of Bit in Underwater MudPenetrator YAN Hui, GE Tong, YANG Ke, WANG Xu-Yang 2012, 46 (03):  446-450.  Abstract ( 2595 )   Save   This article described a new attitude measuring method of bit on the basis of the real operating condition of underwater mudpenetrator. The method which is based on a strapdown inertial system chooses the low frequency value of acceleration and angular rate as the observation and adopts extended Kalman filter to measure the attitude of bit. The results show that the new method is feasible and can improve the navigation accuracy of strapdown inertial system without additional sensor, the drift error decreases from 20°/h to 3°/h.   References | Related Articles | Metrics

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Dynamic Modeling and Analysis of Towed LowTension Cable with Bending and Torsion Effect WANG Fei-1, MA Jian-Wen-2, HUANG Guo-Liang-1 2012, 46 (03):  451-457.  Abstract ( 3377 )   Save  A mathematical scheme was proposed and derived to study the dynamics of towed low tension cable with both bending and torsion moment. According to the principle of the classic lumped mass method, a 4DOF (three degrees of translational motion and one degree of rotate motion) mathematical model was formulated, which is employed to analyze the effect of bending and torsion moment on cable. When modeling, the methods were given to determine the three dimensional bending moment, torsion moment and shear force, while a new variable, zerotorsion moment angle, was introduced to eliminate the effect of cables translational motion on torsion moment and finally get the actual torsion moment, then taking the cables buoyancy, weight, drag and tension into consideration so as to result in the whole mathematical model. Three simulation cases were presented subsequently, the results show good agreement with actual dynamic characters of bending and torsion moments effect, which thus validates the proposed mathematical scheme; these results also turn out some valuable conclusions.   References | Related Articles | Metrics

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Analysis of Flow around Submarine Pipeline Based on Fluent CHEN Xue-Hao, ZHU Zhi-Xia 2012, 46 (03):  458-462.  Abstract ( 3106 )   Save In certain assumptions, the analysis of flow around submarine pipeline in uniflow was simplified to twodimensional flow around cylinder on fixed bed. Incompressible N  S formula and standard k  ε turbulence model were applied to simulate the flow around the pipe on seabed, and the results were consistent with the experimental results. The development (i.e. formation, expansion and shedding) of vortex on the leeside of pipe was simulated for suspended pipe; furthermore, pipes on different conditions (i.e. different elevation and income flow velocities) were calculated, and the most possible scour area was found; flow development, bed shear stress, and pressure distribution characteristics on bed were calculated in order to provide scientific basis of preventing the local scour around subsea pipelines. References | Related Articles | Metrics

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Investigation on Hydrodynamics of a Truss Spar in South China Sea ZHANG Lei-1, YANG Jian-Min-1, ZHANG Yan-Fang-2, LIU Pei-Lin-2, 吕Hai-Ning-1 , LIU Jian-Hui-2 2012, 46 (03):  463-467.  Abstract ( 3389 )   Save Based on 3D potential theory, dynamic coupled timedomain analysis and hybrid model testing technique, investigations are focused on a 1 500 m deepwater Truss Spar in South China Sea with different sea states for operational loading condition. Hydrodynamic performances of the Spar are well predicted including surge, heave and pitch motions. It can be concluded that lowfrequency response of heave and pitch motions should be taken seriously, as well as the surge motion, which is mainly predominant by low frequency response. While the heave motion response seems relatively moderate. It can satisfy the requirements of offshore oil and gas production. References | Related Articles | Metrics

Communication and Transportation

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The Ventilation in Cargo with Reefer Container LIU Jing-1, LIAN Zhi-Wei-1, CHEN Xu-2, SHI Ding-Yue-2, CHEN An-Yang-2, AN Yu-Hui-2 2012, 46 (03):  468-473.  Abstract ( 3838 )   Save The ventilation model of the cargo hold loading refrigerated container was developed based on analogical theory. The criteria equation and the criteria number for the ventilation were introduced. The calculation of the Reynolds number and the application of the energy equation were analyzed. And the dimension of the model was calculated. The construction of experimental setup for cargo with reefer container was introduced, and the temperature distribution of cargo was measured. The research results are expected to contribute to the ventilation optimization. References | Related Articles | Metrics

General Industrial Technology

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Decomposing Numerical Simulation and Experimental Verification of Carbon Dioxide Micro-channel Gas Cooler WU Jiang-Hong, LI Cheng, YANG Zhao-Guang 2012, 46 (03):  474-479.  Abstract ( 3749 )   Save 摘要： 关键词：   In order to investigate the effect of CO2 maldistribution in microchannel on the flow and heat transfer characteristics of gas cooler, decomposing numerical model of microchannel gas cooler in transcritical CO2 system was constructed and experimentally verified. The results show that the maximum flow rate nonuniformity decreases from 97% to 18% as total inlet flow rate of CO2 increases from 110 kg/h to 470 kg/h, meaning that the flow rate is the critical factor of maldistribution. The maldistribution of refrigerant flux has a significant effect on the flow characteristics of microchannel gas cooler. While to the heat transfer characteristics, its effect is not obvious. The numerical results were compared with the experimental data under different running conditions. The inaccuracy of average heat transfer coefficient ranges from 482% to 3825%, and the inaccuracy of friction coefficient ranges from 6.09% to 26.65%. References | Related Articles | Metrics

Aeronautics & Astronautics

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Dynamic Modeling and Simulation to Precision Positioning Magnetostrictive Inchworm Linear Motor XU Wen-Bing, YANG Bin-Tang, MENG Guang, 吕Yang-Ming 2012, 46 (03):  480-486.  Abstract ( 3182 )   Save  This paper presented a research work for the dynamic modeling and simulation to a currently realized giant magnetostrictive inchworm linear motor, which provides an effective method to model giant magnetostrictive inchworm linear motor system and to analyze its performance. JilesAtherton model is introduced to compensate the hysteresis errors, and the rolling friction is taken into account in case a heavy load is applied. The feasibility of linear motor design was verified by modeling and simulating. The model was finally verified by experiments in terms of the frequency characteristic and load characteristic of the motor, and the shape of the simulation curve of step size basically matches up to the experimental curve. The dynamic model presented in this research realizes the precise system simulation with various exciting signals and external loads applied, which gives basis for the future structural optimization of the motor and the design of closed loop system. References | Related Articles | Metrics

General Industrial Technology

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State Diagram of Colostral Whey Powder with Additives YU Hua-Ning-a, LI Yun-Fei-b, c 2012, 46 (03):  487-492.  Abstract ( 2837 )   Save The simplified state diagram of colostral whey powder with additives was constructed by determining the freezing curve (initial freezing point versus solids content), the glass line (glass transition temperature versus solids content), and maximalfreezeconcentration conditions (end point of freezing, T′m, and glass transition temperature of maximallyfreezeconcentrated solution, T′g) using differential scanning calorimetry (DSC). The Chen and GordonTaylor equations were employed for nonlinearly modelling the freezing curve and the glass line, respectively. The results show that the Chen and GordonTaylor equations can well fit the freezing curve and the glass line of colostral whey powder with additives, respectively. The conditions of maximallyfreezeconcentrated solution are 23724 K (T′m) and 22624 K (T′g), respectively. The state diagram of colostral whey powder with additives is a helpful tool for choosing the optimal dehydration process parameters of colostral whey with additives and storage conditions for colostral whey powder with additives. References | Related Articles | Metrics

Aeronautics & Astronautics

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Experimental Study on Ignition Delay of Butanol Using Shock Tube 南Bei , LIU Wen-Jia, LI Zhen-Hua, 吕Xing-Cai , HUANG Zhen 2012, 46 (03):  493-497.  Abstract ( 3493 )   Save Ignition delay of nbutanoloxygennitrogen mixtures were measured behind reflected shock waves in a double diaphragm chemical shock tube at temperature ranges of 1 04332~1 16372 K, pressure at 0671~0835 MPa, and equivalence ratio at 10, 15, and 05 respectively. The experimental results show that the ignition delay of the mixtures decreases with the increase in temperature and equivalence ratio. The logarithmic value of the ignition delay is proportional to the reciprocal of temperature and agrees well with Arrheniustype correlation equation. An Arrheniustype correlation equation for the ignition delay time of butanoloxygennitrogen mixtures was developed. The results illustrate that the ignition delay of butanol shows strong dependence on the pressure, but active energy is less sensitive to the equivalence ratio.   References | Related Articles | Metrics

Chemical Engineering

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Synthesis and Properties of Benzimidazole Group-Containing Sulfonated Polyimide Proton Exchange Membranes   XU Hong, XU Fan, ZHANG Gui-Mei, MA Rui, GUO Xiao-Xia, FANG Jian-Hua 2012, 46 (03):  498-503.  Abstract ( 2924 )   Save A series of benzimidazole groupcontaining sulfonated polyimides (ImSPIs) were synthesized by condensation polymerization of 1,4,5,8naphthalenetetracarboxylic dianhydride (NTDA), two sulfonated diamines, 5amino(2(4aminophenyl)benzimidazole (APABI) and 9,9bis(4aminophenyl)fluorene (BAPF) in mcresol at 180 °C for 20 h. By controlling the molar ratio between the sulfonated diamine and other diamine monomers, ImSPIs with different IECs were obtained. Membranes with good mechanical strength were fabricated by solution cast method. These ImSPI membranes display high proton conductivities at high relative humidities which are comparable or higher than that of Nafion. The incorporation of imidazole groups to polymer structure results in significant improvement in radical oxidative stability but has little effect on the water stability of the membranes.   References | Related Articles | Metrics

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Key Technology of CAE Simulation for Large Complicated Multi-hole Plastic Part YIN Hong-Ling, SUN Mao, XU Zong-Jian, CHEN Jun 2012, 46 (03):  504-508.  Abstract ( 3158 )   Save Considering the large meshing model and timeconsuming computation in large complicated multihole part injection molding simulation, in order to solve the problems, according to the principle of equivalent volume, a simplified method was used to substitute multihole featural section with a simple cross section of shape factor and equivalent thickness and to derivate the formula of shape factor and equivalent thickness. The formula was used to simulate a car rear door panel, which not only decreases the calculation time, but also accurately predicts the location of the weld lines and air traps. The method is useful for the complicated parts with similar features. References | Related Articles | Metrics