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1. |
Parallel fluid dynamics computations in aerospace applications |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 783-805
S. K. Aliabadi,
T. E. Tezduyar,
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摘要:
AbstractMassively parallel finite element computations of the compressible Euler and Navier‐Stokes equations using parallel supercomputers are presented. The finite element formulations are based on the conservation variables and the streamline‐upwind/Petrov‐Galerkin (SUPG) stabilization method is used to prevent potential numerial oscillations due to dominant advection terms. These computations are based on both implicit and explicit methods and their parallel implementation assumes that the mesh is unstructured. The implicit computations are based on iterative strategies. Large‐scale 3D problems are solved using a matrix‐free iteration technique which reduces the memory requirements significantly. The flow problems we consider typically come from aerospace applications, including those in 3D and those involving moving boundaries interacting with boundary layers and shocks. Problems with fixed boundaries are solved using a semidiscrete formulation and the ones involving moving boundaries are solved using the deformable‐spatial‐domain/stabilized‐space‐time (DSD
ISSN:0271-2091
DOI:10.1002/fld.1650211003
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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2. |
Mixed explicit/implicit time integration of coupled aeroelastic problems: Three‐field formulation, geometric conservation and distributed solution |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 807-835
Charbel Farhat,
Michel Lesoinne,
Nathan Maman,
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摘要:
AbstractA three‐field arbitrary Lagrangian‐Eulerian (ALE) finite element/voluem formulation for coupled transient aeroelastic problems is presented. The description includes a rigorous derivation of a geometric conservation law for flow problems with moving boundaries and unstructured deformable meshes. The solution of the coupled governing equations with a mixed explicit (fluid)/implicit (structure) staggered procedure is discussed with particular reference to accuracy, stability, distributed computing, I/O transfers, subcycling and parallel processing. A general and flexible framework for implementing partitioned solution procedures for coupled aeroelastic problems on heterogeneous and/or parallel computational platforms is described. This framework and the explicit/implicit partitioned procedures are demonstrated with the numerical investigation on an iPSC‐860 massively parallel processor of the instability of flat panels with infinite aspect ratio in supersonic airst
ISSN:0271-2091
DOI:10.1002/fld.1650211004
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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3. |
A little more on stabilizedQ1Q1for transient viscous incompressible flow |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 837-856
P. M. Gresho,
S. T. Chan,
M. A. Christon,
A. C. Hindmarsh,
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摘要:
AbstractIn an attempt to overcome some of the well‐known ‘problems’ with theQ1P0element, we have devised two ‘stabilized’ versions of theQ1Q1element, one based on a semi‐implicitapproximateprojection method and the other based on a simple forward Euler technique. While neither one conserves mass in the most desirable manner, both generate a velocity field that is usually ‘close enough’ to divergence‐free. After attempting to analyse the two algorithms, each of which includes some ad hoc ‘enhancements’, we present some numerical results to show that they both seem to work well enough. Finally, we point out that any projection method that uses a ‘pressure correction’ approach is inherently limited totime‐accuratesimulations and, even if treated fully implicitly, is inappropriate for seeking steady
ISSN:0271-2091
DOI:10.1002/fld.1650211005
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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4. |
A numerical study of vortex shedding around a heated/cooled circular cylinder by the three‐step Taylor‐Galerkin method |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 857-867
Katsumori Hatanaka,
Mutsuto Kawahara,
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摘要:
AbstractIn this paper the vortex shedding around a heated/cooled circular cylinder is numerically simulated by solving the time‐dependent Navier‐Stokes and energy equations. A finite element method that is referred to as the three‐step Taylor‐Galerkin method is used to compute these equations. The attention of this study is directed to the investigation of the effect of buoyancy on the vortex street behind the cylinder at constant Reynolds number. The present paper shows the suppression or generation of the von Kármán vortex street behind the cylinder when the cylinder surface is heated or cooled respectively. The relationship between the temperature‐induced buoyancy force and the vortex shedding is also discussed through several numeric
ISSN:0271-2091
DOI:10.1002/fld.1650211006
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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5. |
The parallel processing technique applied to the cellular automation method in fluid dynamics simulations |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 869-875
Yukihiko Inoue,
Kazuyuki Katsuragi,
Osamu Ukai,
Takeshi Adachi,
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摘要:
AbstractThis paper describes an efficient parallel algorithm of the cellular automaton (CA) method for microscopic fluid dynamics simulations. The CA method is parallelized with so‐called multispin coding and with one‐dimensional domain decomposition. The parallel CA method has a constant computational load balance and small data transfer between only nearby domains. We have applied the parallel CA method to a large‐scale Poiseuille flow simulation and an immiscible two‐phase flow simulation on a Fujitsu AP1000 with 64 pro
ISSN:0271-2091
DOI:10.1002/fld.1650211007
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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6. |
A case study in parallel computation: Viscous flow around an ONERA M6 wing |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 877-884
Zdeněk Johan,
Kapil K. Mathur,
S. Lennart Johnsson,
Thomas J. R. Hughes,
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摘要:
AbstractWe examine the solution of a practical engineering problem on a parallel computer. The problem involves the steady laminar viscous flow about an ONERA M6 wing and the computer is a 64‐processing‐node Connection Machine CM‐5E. We show that efficient domain decomposition procedures lead to a balanced load on the processors and low communication times. The net result is that solutions can be attained in roughly 20 min elapsed time for a 48,011‐node, 266,566‐element unstructured mesh. We conclude that this is sufficiently fast to support the desig
ISSN:0271-2091
DOI:10.1002/fld.1650211008
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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7. |
Three‐step explicit finite element computation of shallow water flows on a massively parallel computer |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 885-900
Kazuo Kashiyama,
Hanae Ito,
Marek Behr,
Tayfun Tezduyar,
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摘要:
AbstractMassively parallel finite element strategies for large‐scale computations of shallow water flows and contaminant transport are presented. The finite element discretizations, carried out on unstructured grids, are based on a three‐step explicit formulation both for the shallow water equations and for the advection‐diffusion equation governing the contaminant transport. Parallel implementations of these unstructured‐grid‐based formulations are carried out on the Army High Performance Computing Research Center Connection Machine CM‐5. It is demonstrated with numerical examples that the strategies presented are applicable to large‐scale computations of various shallow water
ISSN:0271-2091
DOI:10.1002/fld.1650211009
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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8. |
Wavelet and multiple scale reproducing kernel methods |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 901-931
Wing Kam Liu,
Yijung Chen,
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摘要:
AbstractMultiple scale methods based on reproducing kernel and wavelet analysis are developed. These permit the response of a system to be separated into different scales. These scales can be either the wave numbers corresponding to spatial variables or the frequencies corresponding to temporal variables, and each scale response can be examined separately. This complete characterization of the unknown response is performed through the integral window transform, and a space‐scale and time‐frequency localization process is achieved by dilating the flexible multiple scale window function. An error estimation technique based on this decomposition algorithm is developed which is especially useful for local mesh refinement and convergence studies. This flexible space‐scale window function can be constructed to resemble the well‐known unstructured multigrid andhp‐adaptive finite element methods. However, the multiple scale adaptive refinements are performed simply by inserting nodes into the highest wavelet scale solution region and at the same time narrowing the window function. Hencehp‐like adaptive refinements can be performed without a mesh. An energy error ratio parameter is also introduced as a measure of aliasing error, and critical dilation parameters are determined for a class of spline window functions to obtain optimal accuracy. This optimal dilation parameter dictates the number of nodes covered under the support of a given window function. Numerical examples, which include the Helmholtz equation and the 1D and 2D advection‐diffusion equations, are presented to illustrate the high accuracy of the methods using the optimal dilation parameter, the concept of multiresolution analysis and the meshless unstructured adaptiv
ISSN:0271-2091
DOI:10.1002/fld.1650211010
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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9. |
Parallel finite element simulation of 3D incompressible flows: Fluid‐structure interactions |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 933-953
S. Mittal,
T. E. Tezduyar,
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摘要:
AbstractMassively parallel finite element computations of 3D, unsteady incompressible flows, including those involving fluid‐structure interactions, are presented. The computation with time‐varying spatial domains are based on the deforming spatial domain/stabilized space‐time (DSD/SST) finite element formulation. The capability to solve 3D problems involving fluid‐structure interactions is demonstrated by investigating the dynamics of a flexible cantilevered pipe conveying fluid. Computations of flow past a stationary rectangular wing at Reynolds number 1000, 2500 and 107reveal interesting flow patterns. In these computations, at each time step approximately 3 × 106non‐linear equations are solved to update the flow field. Also, preliminary results are presented for flow past a wing in flapping motion. In this case a specially designed mesh moving scheme is employed to eliminate the need for remeshing. All these computations are carried out on the Army High Performance Computing Research Center supercomputers CM‐200 and CM‐5, with major speed‐ups compared with traditional supercomputers. The coupled equation systems arising from the finite element discretizations of these large‐scale problems are solved iteratively with diagonal preconditioners. In some cases, to reduce the memory requirements even further, these iterations are carried out with a matrix‐free strategy. The finite element formulations and their parallel implementations assume
ISSN:0271-2091
DOI:10.1002/fld.1650211011
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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10. |
Transient analysis by Laplace transform and combined finite and boundary element methods for convective diffusion problem |
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International Journal for Numerical Methods in Fluids,
Volume 21,
Issue 10,
1995,
Page 955-966
Naotaka Okamoto,
Hideo Sawami,
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摘要:
AbstractA numerical method for solving the problem of transient convective diffusion with a first‐order chemical reaction is presented in this paper. The method is applicable over an infinite region. For steady problems the combined method of finite and boundary elements is recognized as a successful numerical technique for dealing with an infinite region. The present method is also useful in transient problems. In order to formulate the combined method for transient problems, we have developed a new method. In this paper the Laplace transform method incorporating the combined finite and boundary element methods will be considered. This transformation, holding complex values, transforms the transient problem into a steady state form. We also consider the present numerical solution which is obtained by using the numerical inverse Laplace transform as presented by Hosono. In numerical experiments the present method gives us an extremely accurate solutio
ISSN:0271-2091
DOI:10.1002/fld.1650211012
出版商:John Wiley&Sons, Ltd
年代:1995
数据来源: WILEY
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