FINITE ELEMENT ANALYSIS OF VISCOUS FLOW PAST A ROTATING SPHERE

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＶｉｓｃｏｕｓｆｌｏｗｐａｓｔａｂｌｕｆｆｂｏｄｙｈａｓｒｅｃｅｉｖｅｄａｇｒｅａｔｄｅａｌｏｆａｔｔｅｎｔｉｏｎｏｗｉｎｇｔｏｉｔｓｔｈｅｏｒｅｔｉｃａｌａｎｄｐｒａｃｔｉｃａｌｓｉｇｎｉｆｉｃａｎｃｅ .Ｔｈｅｐｒｅｓｅｎｃｅｏｆｖｏｒｔｅｘｓｈｅｄｄｉｎｇ ,ｔｏｇｅｔｈｅｒｗｉｔｈｖｏｒｔｅｘｗａｋｅｓ ,ｉｓｒｅｌａｔｅｄｔｏｔｈｅｐｒｅｓｓｕｒｅｆｌｕｃｔｕａ ｔｉｏｎ ,ｓｔｒｕｃｔｕｒａｌｖｉｂｒａｔｉｏｎ ,ａｎｄｎｏｉｓｅ .Ｔｈｅｂｅｈａｖｉｏｒｏｆｔｈｅｆ…     

FINITE ELEMENT ANALYSIS OF COMPLEX INCOMPRESSIBLE FLOWS

ＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＯＦＣＯＭＰＬＥＸＩＮＣＯＭＰＲＥＳＳＩＢＬＥＦＬＯＷＳ￥ＪｉｎＳｈｅｎｇ（Ｄｅｐｔ．ＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇＤａｌｉａｎＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙ，Ｄａｌｉａｎ＇ａｎ，１１６０２３...     

USE THE EQUATIONS OF TOTAL PRESSURE AND VELOCITY TO SOLVE THE VISCOUS INCOMPRESSIBLE FLOW IN THE CHANNEL

This paper presents a new method to numerically solve the viscous incompress-ible steady flow in a channel with non-uniform section by use of the equations of total pressureand velocity.This method is to solve the equations of total pressure and velocity in the non-or-thogonai curvilinear mesh.The advantages of this method is discussed.     

THE FINITE VOLUME PROJECTION METHOD WITH HYBRID UNSTRUCTURED TRIANGULAR COLLOCATED GRIDS FOR INCOMPRESSIBLE FLOWS

In this article a finite volume method is proposed to solve viscous incompressible Navier-Stokes equations in two-dimensional regions with corners and curved boundaries. A hybrid collocated-grid variable arrangement is adopted, in which the velocity and pressure are stored at the centroid and the circumcenters of the triangular control cell, respectively. The cell flux is defined at the mid-point of the cell face. Second-order implicit time integration schemes are used for convection and diffusion terms. The second-order upwind scheme is used for convection fluxes. The present method is validated by results of several viscous flows.     

FINITE ELEMENT ANALYSIS OF LAMINAR FLOW AND HEAT TRANSFER IN A BUNDLE OF CYLINDERS

In this paper two-dimensional Navier-Stokes equations and energy equation governing incompressible laminar flow past a bundle of cylinders were numerically solved by using the finite element method.The velocity correction method was used for time advancement, and spatial discretization was carried out with the Galerkin weighted residual method.Viscous flows past the cylinder banks arranged in in-line cylinder bundles and staggered cylinder bundles, coupled with heat transfer, were investigated for pitch-diameter ratios of 1.5 and 2.0 and the Reynolds numbers from 50 to 500.Flow structures and heat transfer behavior were discussed.The results obtained agree well with available numerical data.     

HIGH ACCURATE SOLUTION OF INCOMPRESSIBLE VISCOUS FLOW WITH PRIMATIVE VARIABLE

This paper presents a higher order difference scheme for the computationof the incompressible viscous flows.The discretization of the two-dimensional incompress-ible viscous Navier-Stokes equations,in generalized curvilinear coordinates and tensor for-mulation,is based on a non-ataggered grid.The momentum equations are integrated intime using the four-stage explicit Runge-Kutta algorithm [1]and discretized in space us-ing the fourth-order accurate compact scheme[2]The pressure-Poisson equation is dis-cretized using the nine-point compact scheme.In order to satisfy the continuity constraintand ensure the smoothness of pressure field,an optimum procedure to derive a discretepressure equation is proposed [9][3]The method is applied to calculate the driven cavityflow on a stretched grid with the Reynolds numbers from 100 to 10000.The numerical re-sults are in very good agreement with the results obtained by Ghia et al [7]and includethe periodic solutions for high Reynolds numbers.     

NUMERICAL SOLUTION OF INCOMPRESSIBLE VISCOUS FLOW OVER AEROFOIL WITH H-TYPE GRID

The numerical solution of incompressible viscous flow over an aerofoil is obtainedby H-type grids and a special difference scheme. The method of mass flux corection is introducedwith success in order to accelerate convergence in iteration of velocity and pressure calculation.     

NUMERICAL ANALYSIS OF THE FLUID FLOW IN A ROTATING CURVED ELLIPTICAL PIPE

A numerical study was conducted for the fully developed laminar flow in rotating curved elliptical pipe. Due to the rotation, the Coriolis force can also contribute to the secondary flow. The interaction of rotation and curvature complicates the flow characteristics. The boundary fitted coordinate was adopted to study the flow characteristic in the rotating systems. The effects of rotation on the flow transition were studied in detail. The generation and mergence of vortices in rotating curved elliptical pipes were also captured for the first time. The simulation results show that the flow for the case of large aspect ratio of the cross-section is more likely to be unstable than that for smaller one.     

NUMERICAL SIMULATON OF IMPROVED BOUSSINESQ EQUATIONS BY A FINITE ELEMENT METHOD

1 .　INTRODUCTIONAswavespropagatetowardshore ,acombina tionofshoaling ,reflection ,refractionanddiffrac tioneffectsmodifythewaveform .Numericalmod elbasedonthetwo dimensionalBoussinesqequa tionshavebeenshowntobecapableofsimulatingthewavepropagationinthecoastalregionsaccu rately .ThestandardBoussinesqequationsderivedbyPeregrine[2 ] includethelowestordereffectsofnon linearityandfrequencydispersion .Becausetheerrorinthelineardispersionrelationincreaseswiththeincreaseofwaterdepth ,thestandar…     

THE PARALLEL CALCULATION METHOD OF INCOMPRESSIBLE VISCOUS FLOW IN CYLINDRICAL PASSAGE

ＴＨＥＰＡＲＡＬＬＥＬＣＡＬＣＵＬＡＴＩＯＮＭＥＴＨＯＤＯＦＩＮＣＯＭＰＲＥＳＳＩＢＬＥＶＩＳＣＯＵＳＦＬＯＷＩＮＣＹＬＩＮＤＲＩＣＡＬＰＡＳＳＡＧＥＨｅＨｏｎｇ－ｑｉｎｇ；ＺｈｏｕＸｕ；ＣａｉＴｉ－ｍｉｎＣｏｌｌｅｇｅｏｆＡｓｔｒｏｎａｕｔｉｃｓ，...     

NUMERICAL SIMULATION OF 3-D TURBULENT FLOWS IN A CUT-OFF VALVE AND ANALYSIS OF FLOW CHARACTERISTICS IN PIPE

1 .　INTRODUCTIONThevalvehasbeenplayinganimportantroleinthe pipeengineeringandisalsooneofmaincomponentsgeneratingtheheadloss .Becauseofthecomplexgeometry ,thedesignwasusuallyeval uatedempiricallyinthepast,whichcausesmuchenergyloss .Toreducetheenergyloss ,itisessen tialforadesignertoknowthedetailsofflowfieldinthevalvepipe .Recently ,withtheremarkableprogressintheComputationalFluidDynamics(CFD)andcomputerhardware ,itisexpectedthatCFDwillbecomeapowerfultoolinthedesignofvalve .Intheactual…     

AN IMPLICIT SCHEME FOR THE NUMERICAL SOLUTION OF THE TIMEDEPENDENT HEAD／DISK DYNAMICS IN HARD DISK DRIVER BY FINITE ELEMENT METHOD

ＡＮ　ＩＭＰＬＩＣＩＴ　ＳＣＨＥＭＥ　ＦＯＲ　ＴＨＥ　ＮＵＭＥＲＩＣＡＬ　ＳＯＬＵＴＩＯＮ　ＯＦ　ＴＨＥ　ＴＩＭＥＤＥＰＥＮＤＥＮＴ　ＨＥＡＤ／ＤＩＳＫ　ＤＹＮＡＭＩＣＳ　ＩＮ　ＨＡＲＤ　ＤＩＳＫ　ＤＲＩＶＥＲ　ＢＹ　ＦＩＮＩＴＥ　ＥＬＥＭＥＮＴ　Ｍ...     

LATTICE BGK MODEL FOR THE INCOMPRESSIBLE NAVIER-STOKES EQUATION

1 .　INTRODUCTIONInthelastdecadeorso ,theLatticeBoltz mann (LB)methodhasemergedasanewandef fectivenumericaltechniqueofComputationalFluidDynamics (CFD) [1 3] ,especially ,theLBGKmodelhasachieved greatsuccessinsimulationsoffluidflowsandinmodeling physicsinfluids[4 9] .ButLBGKmodelshouldbeviewedasanarticicialcompressibleschemetosimulateincompressiblefluid[10 ] .Inotherwords,throughmultiscalingex pansionandChapman Enskog procedure[11] ,thecompressibleNavier Stokesequationscanberecov …     

3-D SHALLOW WATER FLOW COMPUTATION BY A SEMIIMPLICIT FINITE ELEMENT METHOD

A simi-implicit finite element method is developed for three-dimensional shallow water flow. By using water depth to scale the vertical coordinate, the governing equation is transformed into fixed computational domain. An efficient generalized conjugate gradient scheme is adopted for the solution of finite element analogy.     

空腹重力坝坝踵应力的有限元分析

空腹重力坝的结构比较复杂，用材料力学方法难以求出现踵的真实应力，采取弹性理论的有限元法来分析坝踵应力，对影响坝踵应力的多种因素进行了分析，以便为坝踵应力取值提供设计依据。     

NUMERICAL SOLUTION OF 2-D INCOMPRESSIBLE VISCOUS FLOW WITH HIGH ORDER COMPACT SCHEME USING DOMAIN DECOMPOSITION AND MATCHED METHOD

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｈａｖｅｂｅｅｎｓｔｉｌｌｒａｒｅｐｒｏｇｒａｍｓｆｏｒｃｏｍｐｌｅｘｆｌｏｗｓｉｍｕｌａｔｉｏｎｗｉｔｈＤｏｍａｉｎＤｅｃｏｍｐｏｓｉｔｉｏｎＭｅｔｈｏｄ(ＤＤＭ ) ,ｗｈｉｃｈｔｈｏｕｇｈｗａｓｂｒｉｅｆｌｙｒｅｐｏｒｔｅｄｂｙＺｈｕＺｉｑｉａｎｇ[1] .ＴｈｅｇｅｎｅｒａｌｆｌｏｗｃａｌｃｕｌａｔｉｏｎｓｏｆｔｗａｒｅｓｓｕｃｈａｓＣＦＸ 4 ,Ｐｈｏｅｎｉｃｓａｒｅａｌｓｏｌａｃｋｏｆｔｈｅｆｕｎｃｔｉｏｎｏｎｔｈｉｓａｓｐｅｃｔ.Ｆｏｒｔｈｅｓａｋｅｏｆｐ…     

ISOPARAMETRIC ELEMENT TRANSFORMATION FOR FINITE ANALYTIC METHOD

The Finite Analytic Method (FAM) is a new numerical method for solvingNavier-Stokes equations. However, on complex geometric domains this method must employ theboundary-fitted coordinate transformation, which becomes very difficult for some flow regions.In this paper, the Isoparametric Element, which has been widely used in the Finite ElementMethod, is incorporated into the FAM. The flow region is subdivided into a number of small ar-bitary quadrilaterals, and each element is transformed into a square element by the shape func-tions of Isoparametric Element. Then the partial differential equations on the square element canbe solved by the FAM. As an example, the flow in tube bundles has been calculated by thismethod.     

AN EXPERIMENTAL STUDY OF FLOW FIELD IN THE FLUID HOMOGENIZER

A Laser Doppler Anemometer (LDA) is used to measure and study the flow field in the working chamber of a homogenizer. Flow Patterns, distributions of mean and fluctuating velocities, shear rates are obtained in details. The characteristics of the flow field and the basic principles of homogenizing are presented. These results are very helpful for the improvement of fluid homogenizers.     

A FINITE ELEMENT AND BOUNDARY ELEMENT METHOD OF NUMERICAL SIMULATION OF TWO DIMENSIONAL AND TWO PHASE FLOW

ＡＦＩＮＩＴＥＥＬＥＭＥＮＴＡＮＤＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＭＥＴＨＯＤＯＦＮＵＭＥＲＩＣＡＬＳＩＭＵＬＡＴＩＯＮＯＦＴＷＯＤＩＭＥＮＳＩＯＮＡＬＡＮＤＴＷＯＰＨＡＳＥＦＬＯＷＦａｎＪｉａｎｇ；ＱｕＤｅ－ｂｉｎ；ＺｈａｎｇＺｉ－ｘｉａｎｇ（Ｑｉｎ...     

NUMERICAL SIMULATION OF AN OSCILLATING FLOW PAST A CIRCULAR CYLINDER IN THE VICINITY OF A PLANE WALL

Oscillating flow around a circular cylinder in the vicinity of a plane wall was investigated by solving the two-dimensional incompressible Navier-Stokes equations with a finite element Galarkin residual method. The effect of the gap G/D between the cylinder surface and the wall on the flow behavior was studied. For the case of G/D 〈 0.25, the periodicity in the flow is attributed to both the outer shear layer instability and the oscillating frequency. As G/D 〉 0.25, vortex shedding occurs and the periodicity in the flow is mainly due to the competition of the oscillating frcqucncy and the vortex shedding frequency from an isolated stationary cylinder.