摘要:

AbstractWe present a new conforming bilinear Petrov‐Galerkin finite‐element scheme for elliptic transport problems with variable coefficients. This scheme combines a generalized test function and artificial diffusion to achieveO(h4) grid‐point accuracy on uniform stencils of 3 × 3 in two dimensions without resorting to the extended stencils of high‐order elements. The method is compared with upwind and high‐order finite‐difference schemes and the standard Galerkin finite‐element method for representative test problems. © 1994 John

ISSN:0749-159X    

DOI:10.1002/num.1690100102

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractA deformation method of grid generation has been recently proposed. The method is based on Moser's deformation scheme in his study of the volume elements of a Riemannian manifold. In this paper, this deformation method is improved so that the grid adaption takes place according to the physical coordinates. Some numerical results are included to demonstrate the method. © 1994 John Wiley&Sons, Inc

ISSN:0749-159X    

DOI:10.1002/num.1690100103

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractWith simple finite‐difference operators we construct fourth‐order schemes in space and in time for the wave equation, Maxwell equations, and linearized elastodynamic equations using the modified equation approach. The schemes remain stable for arbitrary heterogeneous mediums because the relevant difference operators are always positive definite. We also present some dispersion curves to show the accuracy of the schemes. © 1994 John Wiley&Sons,

ISSN:0749-159X    

DOI:10.1002/num.1690100104

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractWe develop a model for simulating the growth of a biofilm in a tortuous tube. The solutions to the Navier‐Stokes equations and the advection‐diffusion equation are calculated numerically using finite differences. These solutions are then coupled with a biofilm growth model. © 1994 John Wiley&Sons,

ISSN:0749-159X    

DOI:10.1002/num.1690100105

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractA new multidomain direct (noniterative) method for solving boundary‐value problems is presented. Using this method, the solution is expressed by a linear combination of auxiliary functions and unknowns which pertain to the boundaries of a subdomain. This approach enables us to solve problems independently and exactly, without any iterations between subdomains. As a consequence, different types of equations and coordinate systems may be considered in different subdomains. Moreover, different boundary conditions and variable (in space) time steps may be imposed on the subdomains as well. Applications are given for initial boundary‐value problems with known analytical solutions, including a highly nonlinear porosity equation. © 1994 John Wiley&Sons,

ISSN:0749-159X    

DOI:10.1002/num.1690100106

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThrough numerical experiments we explore the incremental unknowns method; linear stationary as well as evolutionary problems are considered. For linear stationary problems, the method appears as a nearly optimal two‐step preconditioning technique. At each step, we observe that the convergence behavior of the iterative methods employed is dramatically different, depending upon whether or not preconditioning is used. For linear evolutionary problems, successful and sharply accurate long‐term integration is observed when the incremental unknowns (other than that of the coarsest level) are, effectively, small quantities. Otherwise, systematical aliasing arises. © 1994 John Wiley&Sons,

ISSN:0749-159X    

DOI:10.1002/num.1690100107

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY

ISSN:0749-159X    

DOI:10.1002/num.1690100101

出版商:John Wiley&Sons, Inc.    

年代:1994

数据来源: WILEY