摘要:

AbstractA viscosity‐splitting scheme for the initial boundary value problems of the Navier‐Stokes equations is considered. In the scheme, the Stokes equation is solved in conjunction with a nonhomogeneous boundary condition which connects the tangent flow with a no‐slip flow. Convergence is p

ISSN:0749-159X    

DOI:10.1002/num.1690070403

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

ISSN:0749-159X    

DOI:10.1002/num.1690070404

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractWhen fields that describe a physical situation extend over the whole space, but with complex behavior (nonlinearity, coupling, etc.) only in a bounded region and simple behavior in the rest of space, it may be worthwhile to treat the inner field by a finite elements procedure and the outer field by boundary elements. We address this “marriage” problem in the case ofmixedelements. The model problem adopted for this discussion ismagnetostatics. A new approach to the question of mixed elements is used, which emphasizes their parenthood with a classical concept of differential geometry,Whitney fo

ISSN:0749-159X    

DOI:10.1002/num.1690070405

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractWe approximate the Stokes problem by using a finite element method. This method utilizes the approach of Kleiser–Schumann, in which a boundary condition for the pressure is implicitly defined by a condition on the velocity. We consider a suitable splitting of the unknowns that allows one to reduce the Stokes problem to a cascade of classical Dirichlet problems and to a boundary integral equatio

ISSN:0749-159X    

DOI:10.1002/num.1690070406

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper addresses a hybrid computational procedure for the step‐by‐step calculation of momentum transfer in turbulent boundary layer flows along flat plates. The proposed procedure relies on a modified method of lines wherein transversal discretizations are carried out by a “control volume” being infinitesimal in the streamwise direction and finite in the transversal direction of the fluid flow. Using mixing length theory and coarse intervals in the transversal direction, the resulting system of ordinary differential equations of first order may be readily integrated on a personal computer utilizing a fourth‐order Runge‐Kutta algorithm. In general, a maximum number of sixteen lines is necessary at the trailing edge of the flat plate for a typical calculation. As a consequence, computing time and storage for each run were very small when compared to other finite‐difference methods. Furthermore, to validate the hybrid procedure involving the method of lines and control volumes (MOLCV), comparisons with experimental data have been done in terms of both velocity distributions and local skin friction coefficients. For all cases tested, the proposed methodology predicts the growth of the boundary layer of ga

ISSN:0749-159X    

DOI:10.1002/num.1690070407

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractWe investigate various aspects of the dynamics of a discrete reaction‐diffusion system. First, we examine the effect of the boundary conditions on the spatially uniform fixed point at locations far from the boundaries by using an asymptotic expansion. We show that, except for a few computational cells adjacent to the boundary, the fixed point practically coincides with the one calculated by using reflective boundary conditions (equivalent to an infinite domain). Next, we introduce a classification of the fixed points based on the wavelength in the infinite‐medium approximation of the system. We use the symbolic manipulator MACSYMA to analytically calculate the amplitude of several such classes of fixed points and we generate bifurcation diagrams for their members. Also, we consider two special classes of periodic solutions; we calculate their amplitude analytically in the infinite‐medium approximation, and generate bifurcation diagrams that shed new light on some previous confusing results. Finally, we present an analysis of fictitious periodic solutions that have been previously reported and incorrectly interp

ISSN:0749-159X    

DOI:10.1002/num.1690070408

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

ISSN:0749-159X    

DOI:10.1002/num.1690070402

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY