Table of Content

    29 April 2011, Volume 45 Issue 04 Previous Issue    Next Issue
    Communication and Transportation
    Experimental and Numerical Analysis for Floatover Installation on Jacket
    XU Xin, YANG Jian-Min, LV Hai-Ning
    2011, 45 (04):  439-445. 
    Abstract ( 5663 )   Save
    This paper investigated the floatover installation process on a jacket with numerical and experimental analysis. Numerical analyses in both frequency and time domain were carried out for typical configurations during floatover operation. Corresponding model tests were also performed in ocean engineering basin. The comparison between numerical and experimental results shows that the response amplitude operator and time series agree quite well. The barge has favorable hydrodynamic behavior in considered sea state and the loads of equipments are allowable. The floatover operation on the jacket is feasible.
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    Research on Grout Consolidation Deformation Characteristics  of Backfill Grouting of Shield Tunnel
    YUAN Xiao-Hui, HAN Yue-Wang, ZHONG Xiao-Chun
    2011, 45 (04):  446-450. 
    Abstract ( 4618 )   Save
    Abstract: In order to investigate consolidation deformation characteristics of grout in shield tail void, the changing regulars were tested under different consolidation pressures, different grout material mix ratios, surrounding soil type, and groundwater pressures utilizing the selfmade consolidation deformation device. With consolidation pressure increasing, consolidation rate is accelerated, and ultimate deformation is bigger accordingly. Ultimate strain of consolidation varies between 4% and 12%. Consolidation deformation rate in sandy soil is faster than that in clay soil. Grout consolidation deformation can be stabilized within about 1 hour in sandy soil, which needs 5~6 hours in clay soil. With the water pressure increases, grout drainage rate slows, the final consolidation deformation reduces accordingly. Groundwater pressure hinders grout drainage, reduces the rate of consolidation deformation.
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    An Estimation Algorithm for Soil Parameters for Air-Cushion Vehicles
    XU Shuo, YU Fan, LUO Zhe, Pham D T, JI Ze
    2011, 45 (04):  451-456. 
    Abstract ( 3770 )   Save
    By taking advantage of the additional degree of control freedom for vertical force, a new estimation algorithm, the hybrid g-EKF algorithm, was proposed for air-cushion vehicles. In g-EKF, the g-function solves the multi-solution problem, and the extended Kalman filter (EKF) improves estimation accuracy by decreasing measurement uncertainties. Its advantages are demonstrated in two experiments, namely, estimation accuracy for different noise levels and stability in repeated tests.
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    Identification of the Vehicle Handling System Based on Subspace Method
    GUAN Xi-Qiang, YUAN Ming, ZHANG Jian-Wu
    2011, 45 (04):  457-463. 
    Abstract ( 3618 )   Save
    The system identification of vehicle handling dynamic model was investigated by the subspacebased identification method under linear conditions that the cornering vehicle velocity remains constant. The identification procedure was proposed for construction of inputoutput correlations to vehicle handling dynamics of the linearized system operating at a given speed. The identified dynamic model of the three degrees of freedom was constructed and the identifiability was verified according to the set of assumptions of subspace identification algorithms. Numerical examples were made for the vehicle lateral dynamics model identification and verification using real road test results obtained in two different manoeuvres at the same speed. It is demonstrated by comparisons between the predicted and test results that the present approach is efficient and convenient in the identification of vehicle handling stability systems subjected to the freely parameterized model. 
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    Study on Multi-objective Optimization of a New Side-load Spring  for MacPherson Suspensions
    LIU Jiang, WANG Yu-Shun, YU Fan
    2011, 45 (04):  464-469. 
    Abstract ( 5037 )   Save
    Aiming at decreasing shock absorber’s side load in the MacPherson suspension system, improving suspension performances and reducing manufacture cost, a multiobjective optimization approach was proposed. This virtualprototypebased approach combines the penalty function algorithms SUMT, vehicle system dynamics simulation and finite Element Analysis. Taking a small passenger car as an example, structure parameters were optimized for this curved side load spring. The results of vehicle dynamics simulation, the experimental data of test rig and on road test indicate the improvement of ride performances, in which the side load on damper rod reduces almost to zero and the first resonance peak amplitude of the body acceleration decreases by nearly 24.37%. Besides, the average weight of spring samples also reduces by 2.71% so as to save the manufacture cost.
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    The Wave Loads and Outrigger Hulls’ Position Optimization for Trimaran Traveling in Waves
    XU Min, ZHANG Shi-Lian
    2011, 45 (04):  470-474. 
    Abstract ( 4088 )   Save
    Because of the interaction between the main hull and the outrigger hulls the wave loads will be quite different by different arrangement. Based on the threedimensional potential theory and Green’s function, the wave loads, including vertical shear force end vertical bending moment at different locations on the main hull with respect to different staggers and clearances, were derived by the spectral analysis. Several ship speeds and wave headings were also considered. A suitable arrangement was got by comparison.
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    Experimental Study on Resistance Reduction of Displacement Type Deep-V Hull Model Using Stern Flap
    ZHENG Yi, DONG Wen-Cai, YAO Chao-Bang
    2011, 45 (04):  475-480. 
    Abstract ( 5976 )   Save
    Model tests of kiloton displacement type deep V ship series using stern flap for resistance reduction were carried through. The flap chord varies from 0.010 Lwl to 0.023 Lwl, install angle changes from 3° to 10°, and the test speed range from Fr=0.12 to 0.52. The influence of ship speed, flap chord and install angle on resistance reduction rate and running trim were investigated based on test data. Optimized stern flap parameters with application range were obtained for this particular ship form.
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    Modeling and Simulation on Static Characteristics of Pressure Reducing Valve for Ship’s Diesel Engine
    WEN Xue-Dong, HE Guo, XU Bai-Hui
    2011, 45 (04):  481-485. 
    Abstract ( 5278 )   Save
    A kind of gas pressure reducing valve (PRV) fitted by towdirection for a marine diesel engine was developed. The valve disc is served as a pressure feedback unit and the delivery pressure can be adjusted continuously from 1.3 MPa to 1.5 MPa. A pressure reducing valve static characteristics mathematical model was developed by analyzing the nonlinear factors——frictional and fluid dynamic forces, and the influences of several structure parameters on static behavior of the valve were also given. Equipment for testing the static character of the valve was designed and the several groups of operation condition were tested. The results of the simulation indicate that the model can forecast the static performances, and the valve can meet the needs completely.
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    Integrated Lifting Line Theory and RANS Simulation for Propeller Design and Hydrodynamics Prediction
    YANG Qiong-Fang, WANG Yong-Sheng, HUANG Bin, LIU Deng-Cheng
    2011, 45 (04):  486-493. 
    Abstract ( 5216 )   Save
    Both of the Lerbs nonoptimum propellers theory and Epps optimum circulation distribution theory were adopted to enlarge the propeller traditional liftingline preliminary design to open water performance curves prediction. All of the DTMB 4119, 4381, 4382, 4497 propellers’ offdesign performances were analyzed by this method. The precision of the Epps method is higher than that of Lerbs, and is fit for engineering preliminary analysis. With furthering away from the design point (low and high advance coefficients), the prediction difference gets larger, and the skew angle amplitude and the rake exist will also increase the prediction error. To overcome the moderately loaded limit and analyze blade cavitation performance comprehensively within the viscous field, the liftingline theory and RANS simulation were integrated to enhance offdesign hydrodynamic characteristics prediction. The blade section offsets input to RANS calculation were obtained from liftingline method. Blade geometry modeling and hex meshes were both completed by procedure control.  After analysis of mesh sensitive effects on RANS simulation, the calculated thrust and torque coefficient and pressure coefficient distribution are all fit well with the experiment. After the mixture homogeneous cavitation model is adopted into the RANS simulation, the results quantitatively present the blade tip vortex filament’s helical track within a little distance, in which the smallest pressure magnitude can be combined with the cavitation bucket performance of the biggest load section to relatively determine the propeller’s cavitation performance. The numerical system for propeller parametric design and noncavitation and cavitation hydrodynamic performances prediction based on hydrodynamics was constructed.
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    The Influence of Side Hulls Layout on Longitudinal Motion of  Pentamaran in Wave
    CHEN Zhen, WEN Jun-Hua
    2011, 45 (04):  494-500. 
    Abstract ( 4372 )   Save
    For different position of side hulls of pentamaran, the influence of side hulls layout on longitudinal motion was studied. Rankine panel method was used to calculate the motion response RAO of pentamaran with 12 side hulls layout schemes in regular wave and the effect of side hulls layout relative to main hull on motion was analyzed according to the results. Considering the nonlinear factor, the motion history of pentamaran in irregular wave was calculated and the statistic significant values of heave and pitch motion were compared. The influence of side hulls layout of pentamaran on longitudinal motion is closely related to sailing speed. Sailing at lower speed, the heave motion of pentamaran could decrease when the back side hulls lying near midship and converse trend appears at high speed. Reducing the height and lying near bow of front side hulls could help improve the heave and pitch motion of pentamaran.
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    Identification of Response Models of Ship Manoeuvring Motion Using Support Vector Regression
    ZHANG Xin-Guang, ZOU Zao-Jian
    2011, 45 (04):  501-504. 
    Abstract ( 4446 )   Save
    Abstract: By applying the LSsupport vector regression to analyze the data of rudder angle and yaw rate obtained from the deformed zigzag test of freerunning model, the manoeuvrability indexes in the response models of ship manoeuvring motion were identified. The obtained response models were solved numerically by RungeKutta method to simulate the deformed zigzag manoeuvres. The prediction results of heading angle and yaw rate were compared with the test data to verify the proposed method.
    Key words: ship manoeuvring; response model; parameter identification; support vector regression
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    Improvement to a Design Method for
    Highly Skewed ContraRotating Propellers of Underwater Vehicles
    ZHANG Tao, SONG Bao-Wei, YANG Chen-Jun
    2011, 45 (04):  505-509. 
    Abstract ( 4203 )   Save
    The design method based on liftingline and liftingsurface theories for highly skewed contrarotating propellers was studied. An improved approach for designing the pitch distribution and camber surface was devised and incorporated into the existing design procedure to enhance its efficiency and accuracy. The design example and its numerical validation results indicate that the improved procedure is capable of enhancing computational efficiency and producing smooth blade geometries. The present method provides a useful tool for the design of highly skewed contrarotating propellers.
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    Improved Origin User Equilibrium Algorithm for Traffic Assignment
    ZHANG Tian-Ran
    2011, 45 (04):  510-516. 
    Abstract ( 4943 )   Save
    Key tactics of an origin user equilibrium (OUE) algorithm such as flow shift from max to minpaths, bush update and the algorithm’s procedure were studied. The finding of max and minpaths segmentation pair, the step size of bush flow shift and bush construction were studied to speed up the convergence. The algorithm’s procedure was also optimized to take the advantage of multithread process. Convergence performances were compared with other algorithms by different size of urban transportation network. The improved OUE algorithm is more efficient and converges satisfactorily in a practical application.
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    Architechural Science
    Numerical Simulation of Wind Loading Shape Coefficient  on a New Airport Terminal
    CHEN Xiang-Qiao, TU Jia-Huang, ZHOU Dai, ZHU Zhong-Yi, QIN Kai
    2011, 45 (04):  517-522. 
    Abstract ( 4958 )   Save
    Based on the project of new Kunming Airport Terminal, the wind field and wind pressure distribution of structural surface was simulated by commercial computational software with standard kε turbulent model, while parameter analysis such as coming wind angle was carried out. The investigation indicates that the numerical results of wind pressure distribution on the roof are somewhat greater than the wind tunnel experiment results and the wind loading shape coefficients vary greatly with the coming wind angles. It should be mentioned that the most unfavorable wind pressure distribution should be obtained according to local wind environment, in order to provide a reference for windresistant design of practical eningeering project.
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    Elastified Procedure for the Formfound Equilibrium State  and Zero-stress State of Cable-net Structure
    CHEN Wu-Jun, ZHANG Li-Mei, DONG Shi-Lin
    2011, 45 (04):  523-527. 
    Abstract ( 5148 )   Save
    Six states and five analysis processes were pointed out for the whole numerical analysis process of cable-net structure. The six states are initial geometry state, form-found equilibrium state, elastified form-found equilibrium state, zero-stress (unstressed) state, pre-stress state and loading state, respectively. The five analysis process are form-finding analysis, elastified cable analysis, pre-stress analysis, inverse analysis and loading analysis. And the state parameters were clarified, also for the analytical model of different analysis procedures. The real zero-stress state does not exist generally, the assumed approximated zero-stress state is usually employed. On the basis of elastified form-found equilibrium state, the bestfit reasonable zero-stress state can be found through inverse analysis. The numerical algorithm and procedure was proposed for the ANSYS and EASY for cable-net analysis, and the emphasis is focused on the zero-stress state assumption. Finally, the numerical analysis was exemplified for two cablenet structures. The results demonstrate the significant difference with different zero-stress state assumption and the corresponding numerical analysis approaches.
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    EqualStability Level Based Optimal Stiffener Design for Moderately Thick Plates
    CHENG Bin, ZHAO Jin-Cheng, XIAO Ru-Cheng
    2011, 45 (04):  528-533. 
    Abstract ( 4234 )   Save
    Based on the theory of flexiblestiffener, an equalstability level based optimal stiffener design method was proposed for moderately thick plates by taking the uniaxially compressed stiffened panels as objects and utilizing the ultimate strength formulations of weakly stiffened thick panels. During the optimization process, the numbers and geometric sizes of stiffeners are chosen as design variables; the weight ratio of stiffeners to plate is defined as single objective function; a series of restrictions such as stiffened panel collapsing according to the overall buckling mode, stiffeners and plates between stiffeners being avoided from locally buckling, and panel’s ultimate strength meeting the corresponding design requirements are set as constraint functions. Two optimization theories named constrained mixed integer nonlinear programming (CMINLP) and constrained nonlinear programming (CNLP) are adopted, and two optimization tools, MATLAB and YALMIP, are employed. The results of examples show that the equalstability level based optimal stiffener design is safe and feasible for moderately thick plates. The present method gives a more economical stiffener layout than the current rigidstiffener design method on the premise of the same requirement of panel’s ultimate strength, and the stiffener’s consumption is less as the panel’s slenderness ratio is decreased.
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    Application of HybridModel Method in UltraLarge Water Conveyance Tunnel
    YANG Yan-Zhi, JIN Xian-Long, GU Bin, QIAO Zong-Zhao, YANG Zhi-Hao
    2011, 45 (04):  534-538. 
    Abstract ( 3538 )   Save
    This paper proposed a hybridmodel method based on an ultralarge water conveyance tunnel under construction, which directly performs global simulation and local simulation together, and can avoid the deviation brought by boundary condition gained from global simulation. Using the explicit algorithm and related technologies, it proves this method is feasible through the actual calculation and application.
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    Study on Implementing Derivative Problems of  Design-Build Construction Projects in Taiwan
    WANG Dan-Qi, WANG Long-Chang
    2011, 45 (04):  539-546. 
    Abstract ( 3111 )   Save
    The design-build construction project is implemented in Taiwan not by a single company but by a make-shift group of several companies. Hence, problems to coordinate the professional construction management and the supervising architectural company often occur for lack of longterm experience to work together.  In this research, the various factors that affect the implementation of designbuild projects currently practiced in Taiwan were analyzed using the analytic network process (ANP). The objective is to study how the twelve key factors in the four layers of “Role Assignment”, “Signing Contract”, of implementing the designbuild project in Taiwan. The results reveal that “Delay in Payment” has the most negative influence with 15.62% weighing factor; “Latent Risk” comes next with 11.14% weighing factor, and “Responsibility of Construction Company for Project Quality” is the third with 10.79% weighing factor.
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    Three-Dimensional Numerical Analysis of Soil Nailing for Deep Excavation
    DING Yong-chun, ZHOU Shun-xin, WANG Jian-hua
    2011, 45 (04):  547-552.  doi: 10.16183/j.cnki.jsjtu.2011.04.019
    Abstract ( 5121 )   HTML ( 427 )   PDF (1058KB) ( 1186 )   Save

    In order to investigate the deformation characteristics and load transfer mechanism of deep excavation, a numerical model considering the process of stepped excavating and soil nailing was established by FLAC 3D. The lateral displacement of excavation surface and outside soil, the shear strain increment of soil, and the axial force distribution of nail were analyzed. The results show that, the maximum lateral displacement appears close to slope toe, meanwhile, outside corner is the most disadvantageous location of deflection, and the multilevel platforms have positive effects on controlling soil deformation. Tensile failure and shear failure are the two main failure modes of excavation slope. The location of potential sliding surface can be indicated by shear strain increment contour, and the location moves toward the outside end of soil nail due to soil nail reinforcement effects. The maximum axial force of soil nail appears near the middle and the relative minimum value near the two ends, and the distribution of maximum axial force agrees well with the potential sliding surface.

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    Architechural Science
    Numerical and Experimental Analysis on Mode II Fracture Regular Pattern of the Marble
    QIU Yi-Ping-1, QI Jing-Hua-1, WU Xue-Ping-1, CHEN Lei-2
    2011, 45 (04):  553-560. 
    Abstract ( 3841 )   Save
    The in-plane mode II fracture of the Athenian marble slab with double parallel notches is studied in virtue of the finite element procedurecombined with rock tests. The analysis incorporates the influence of fracture behavior resulting from variation in both the position of the double notches and the cases of loading scheme. Based on the analysis of the numerical simulation, it is shown that the mode II fracture would take place when the ratio a/w is less than 0.3 in the two cases of loading scheme. After the geometrical correction factor is obtained from the results of the finite element method by the polynomial fitting method, the fracture toughness values, KIIC, determined for the specimens based on the ultimate load from the experiments and the geometrical correction factor. It is found that the value a/w is a critical parameter to determine the occurrence of the mode II fracture in the slab through the auxiliary splitting tensile tests.
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    Modeling and Stability Analysis of a Pressure Compensator for Flow-Control Valve
    JIA Wen-Hua- , YIN Chen-Bo
    2011, 45 (04):  561-564. 
    Abstract ( 5676 )   Save
    The forces acting on the load-sensing compensated valve were illustrated and analyzed, the mathematical model was generated using classical momentum principles, while the linear analysis of this was carried out using the Taylor expansions. The valve motion of the system was described by presenting the equation of motion, the stability condition was given by Routh-Hurwitz stability criterion and the dynamic properties of the compensator were studied. The CFD analysis of the compensator was described to study the effect of the force acting on the bottom of the compensator. The pressure along the bottom wall was noted and its variation was plotted against the geometrical position of the bottom wall that it acted on. Noted that this pressure remain constant along the wall. Then, some plots describe the flow induced forces and coefficients used to understand the stability of the compensator itself.
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    Ocean Engineering
    Fatigue Analysis of Offshore Wind Turbine Mono-pile Support Structure
    MO Ji-Hua, HE Yan-Ping, LI Yong-Gang, ZHANG Er-Hu
    2011, 45 (04):  565-569. 
    Abstract ( 5797 )   Save
    WAsP was used to analyze the data of a wind farm and the wind speed distribution was gained. The parameters of wind, wave and current for each working condition were calculated. On the basis of fatigue loads, ABAQUS was used to model the support structure and the stress response time history was figured out through mode superposition method. According to S-N curves, rainflow counting method and Miner’s linear damage theory, Fe-safe was used to work out the fatigue life of the support structure and the effect of different kinds of loads on fatigue life was also researched. The results show that the fatigue life of the support structure meets demand. Wind turbine loads are the key influence factor of fatigue life. Sensible generator control strategy is good for increasing fatigue life. The method that defining working condition through wind direction and 10 minute mean wind speed can be used in fatigue analysis of offshore wind turbine support structure.
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    Dynamic Research on the Coupling Response of  Cable-Towing Ship System
    WANG Fei-1, HUANG Guo-Liang-2, WU Sheng-Chun-1
    2011, 45 (04):  570-575. 
    Abstract ( 4767 )   Save
    In order to further improve the prediction precision of underwater towed system, this paper treats cable and surface towing ship as a whole, and proposed a scheme to investigate the steady and dynamic response of cabletowing ship system using numerical method when the system was under maneuver of surface ship’s rudder and propeller, in which the coupling effect between cable and towing ship plays an important role. The MMG model was introduced to describe the motion of surface towing ship, while the cable was modeled by classic Lumped Mass Method; the kinematic and dynamic boundary conditions between them were proposed to unite cable and ship together and thus result in the whole mathematical model, which was solved by the 4th order RungeKutta integration procedure. Numerical simulation was carried out to analyze the system’s response. The results illustrate that the coupling effect between them would lower the velocity and loop maneuver performance of system, and the prediction precision is improved for the ship’s kinematic response of itself is considered during maneuvering process.
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    Structural Reliability Analysis of Deepwater Risers  in Catastrophic Ocean Environment
    CHEN Chang-Song, XUE Hong-Xiang, TANG Wen-Yong, HU Zhi-Qiang
    2011, 45 (04):  576-580. 
    Abstract ( 3845 )   Save
    A reliability analysis methodology for deep-water riser systems in catastrophic sea state was presented. Based on the advanced time domain couple analysis for deep-sea platforms and finite element dynamic response analysis for risers, the load probability model in catastrophic environment was conducted using generalized extreme value (GEV) theory. Based on structural reliability technique, the limitstate model was developed and the reliability and sensitivity analysis was performed. This methodology takes coupling effect of deep-sea platforms fully into account, which can provide a useful method for reliability assessment of deep-water risers in catastrophic sea state.
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    Secondary Deep-sea Towed System’s Transient Motion Simulation and Heave Compensation
    PEI Yi-Qun, LI Ying-Hui
    2011, 45 (04):  581-584. 
    Abstract ( 4277 )   Save
    The dynamic model of the cable was established by adopting the mass method, and then the numerical analysis to the partial differential equation of second order was done by the means of RungKutta algorithm when the boundary conditions and initial conditions are given. The results demonstrate that the dynamic stabilization exists and the effect of the heave compensation is well.
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    Dynamic Response Analysis of Deepwater Steel Catenary Riser Based on the Seabed-Suction and Stiffness-Degradation Model
    WANG Kun-Peng, XUE Hong-Xiang, TANG Wen-Yong
    2011, 45 (04):  585-589. 
    Abstract ( 5482 )   Save
    A touch-seabed element was created in ABAQUS to simulate the soilriser interaction which is reduced to three models: linear stiffness, linear stiffness with soil-riser’s separateness, soilriser’s separateness and considering the suction and the degradation of the seabed. Considering the floater’s z-motion at the riser’s top boundary, the three models were analyzed and compared. The result shows that the soil-riser’s separateness and suction have great effect on the computation result. If the model considers the suction,there will be many stress cycles at the soil-riser separateness stage. The third touch-seabed element well shows the generation and release of suction, and the seabed stiffness degradation model included in it also gives satisfactory results.
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    Wave-current Numerical Model for Shanghai Nanhuizui Inning Project
    ZHU Zhi-Xia-1, LI Bei-2
    2011, 45 (04):  590-596. 
    Abstract ( 4269 )   Save
    Located in the Nanhui Beach, where the Yangtze River estuary joins up Hangzhou Bay, Shanghai Nanhuizui inning project is the key project for developing and utilizing Shanghai tideland resources.  The interactions between currents, tides and waves in the sea area perform an important function to the success of this project.  A twodimensional numerical model tidal current and the thirdgeneration nearshore wave model SWAN were applied to establish the twodimensional wavecurrent numerical model. The model was verified by the hydrology data measured in August 2006 and the wave survey conducted between 1979 and 1998 in Dajishan station and between August 1997 and July 2001 in Yangmeizui station.  The results indicate that it has good agreement after comparing the modeled tidal levels, tidal current velocity, direction and significant wave heights with measurements.  This study also emphasizes the effects and changes on the current and wave caused by the inning project around the south passage of the Yangtze River estuary, the north shore of Hangzhou Bay, the Donghai Bridge, the landing point closing to LNG pipeline, and the Yangshan deep water harbor.
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    Potential Energy Study of Mooring System Based on Catenary Method
    YUAN Meng, FAN Ju, ZHU Ren-Chuan, MIAO Guo-Ping
    2011, 45 (04):  597-603. 
    Abstract ( 3981 )   Save
    To understand the mooring energy during positioning, the configuration and tension of three types of mooring lines were derived using catenary formula. The gravitational and elastic potential energy distributions of a single mooring line with the lower end fixed were calculated for different upper end positions. The horizontal force calculated from potential energy was compared with that of calculation directly, and the results show good agreement, and satisfy the law of conservation of energy and also prove the correctness of the results of potential energy. For a deep-water platform moored by nine composite mooring lines, the potential energy distributions of the mooring system were analyzed, and the offset-lateral force relations were compared in different directions. They are found to meet each other very well, which indicates a balanced performance of the mooring system. The potential energy distributions and the offsetlateral force relations in different wave directions were calculated for the damaged case. From the results, it can be found that the potential energy distribution can reflect the performance of the mooring system in all directions effectively, which has important practical value in ocean engineering.
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    Aeronautics & Astronautics
    The Interaction of Tip Vortices with Lift of Flapping Plate
    YU Xian-Zhao, SU Yu-Min, LI Xin
    2011, 45 (04):  604-608. 
    Abstract ( 3315 )   Save
    The lift, drag performance and flow structures of 2-D and 3-D flapping flat plate were calculated at the Reynolds number of 100. Navier-Stokes equations were solved by finite volume Method; the dynamic mesh method was taken to remesh the dynamic mesh in conjunction with the spring-based smoothing method and the Laplacian smoothing method. The parallel processing was applied to the 3-D cases to speedup the calculation. The lift performance of delayed rotation and synchronized rotation were calculated, the pressure distribution in the near region of the flapping plate was highlighted to illustrate the relationship of tip vortices and lift enhancement. The calculation results show that the interaction of tip vortices with lift performance is associated with the kinematic parameters of the flapping plate that can either promote the lift of the plate of the delayed rotation, or make a little impact of the synchronized rotation.
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