In this paper, baized on the natural boudary reduction suggested by Feng and Yu, an overlapping domain decomposition method for biharmonic boundary value problems over unbounded domains is presented. By taking advanta...
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In this paper, baized on the natural boudary reduction suggested by Feng and Yu, an overlapping domain decomposition method for biharmonic boundary value problems over unbounded domains is presented. By taking advantage of the map ping theory, the geometric convergence of the continuous problems is proved. The numerical examples show that the convergence rate of this Schwarz iteration is in dependent of the finite element mesh size basicly, but dependent on the frequency of the real solution and the overlapping degree of subdomains.
We present an efficient algorithm to model a collection of scattered functional data on a given smooth surface D in three dimensional real space by a C1 piecewise trivariate rational function F over a collection of te...
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We present an efficient algorithm to model a collection of scattered functional data on a given smooth surface D in three dimensional real space by a C1 piecewise trivariate rational function F over a collection of tetrahedra that contains D.
A second order accurate implicit finite difference scheme CNMT2 is proposed in this paper for the unsteady incompressible Navier-Stokes equations. It is proved that the scheme is unconditionally nonlinearly stable on ...
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A second order accurate implicit finite difference scheme CNMT2 is proposed in this paper for the unsteady incompressible Navier-Stokes equations. It is proved that the scheme is unconditionally nonlinearly stable on smoothly nonuniform halfstaggered meshes; this stability also holds for this scheme with the pressure correction projection method. However, it is found that the pressure correction projection method may lead to deviation problems in practical simulation of high Re flow;the reason and the cure is given in this paper in terms of differential-algebraic equations.
Large-particle (FLIC) method, presented in 1960’s, is a numerical method that be applied to solve unsteady flow. The computational scheme consists of two steps for each timemarch step: First, intermediate values are ...
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Large-particle (FLIC) method, presented in 1960’s, is a numerical method that be applied to solve unsteady flow. The computational scheme consists of two steps for each timemarch step: First, intermediate values are calculated for the velocities and energy, takinginto account the effects of acceleration caused by pressure gradients; Second transport effects are calculated. In this paper, we present a high resolution large-particle finite volumemethod for 2-D unstructured triangular mesh, the key idea of this method is monotonereconstruction of flow variables and solve "Riemann" problem in the first step. Finallythe result of the computation is
In this paper, we review some recent developments on the study of implicitly defined curves and surfaces in the field of computer aided geometric design(CAGD), includ-ing mainly the research on the problems of paramet...
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In this paper, we review some recent developments on the study of implicitly defined curves and surfaces in the field of computer aided geometric design(CAGD), includ-ing mainly the research on the problems of parametrization, regularity and splines of algebraic curves and surfaces.
The generalized Stein-Rosenberg type theorem is established for the parallel decomposition-type accelerated overrelaxation method (PDAOR-method) for solving the large scale block systems of linear equations. This ther...
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The generalized Stein-Rosenberg type theorem is established for the parallel decomposition-type accelerated overrelaxation method (PDAOR-method) for solving the large scale block systems of linear equations. This thereby affords reliable criterions for judging the convergence and divergence, as well as the convergence rate and divergence rate, of this PDAOR-method.
In this paper, we study the acoustic impedance inversion of 1-dimensional wave equation excited by a wavelet. In order to avoid the ill-posedness, a stable method,which we call the characteristic band method, is const...
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In this paper, we study the acoustic impedance inversion of 1-dimensional wave equation excited by a wavelet. In order to avoid the ill-posedness, a stable method,which we call the characteristic band method, is constructed, and then used as the preconditioner in optimal inversion to increase the speed of convergence.
In this paper,we discuss a Schwarz alternating method for a kind of unboundeddomains, which can be decomposed into a bounded domain and a half-planar domain. Finite Element Method and Natural Boudary Reduction are use...
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In this paper,we discuss a Schwarz alternating method for a kind of unboundeddomains, which can be decomposed into a bounded domain and a half-planar domain. Finite Element Method and Natural Boudary Reduction are used alternatively. The uniform geometric convergence of both continuous and discrete problems is proved. The theoretical results as well as the numerical examples show thatthe convergence rate of this discrete Schwarz iteration is independent of the finiteelement mesh size, but dependent on the overlapping degree of subdomains.
The incompressible Navier-Stokes (INS) equations upon discretization on fixed meshes become a system of differential algebraic equations (DAE) of index 2. It is proved in this paper that for the general explicit and i...
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The incompressible Navier-Stokes (INS) equations upon discretization on fixed meshes become a system of differential algebraic equations (DAE) of index 2. It is proved in this paper that for the general explicit and implicit Runge-Kutta (RK)methods, the time accuracy of velocity is the same as that for the ordinary differential equations, by taking into consideration of the special form of the resulting DAE; (the time accuracy of pressure can be lower). For the three-stage secondorder explicit RK method, algorithms with less (than three) Poisson solutions of pressure are proposed and verified by numerical experiments. However, in practical computation of complex flows it is found that the method must satisfy the so-called consistency condition for the components of the solution (here the velocity and the pressure) of the DAE for the method to be robust.
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