摘要:

AbstractThe Q2/P1, P 2+/P1, P2/P0and Q1/P0velocity–pressure mixed elements are extended to the stress–velocity–pressure formulation, using the same interpolants for stress and velocity, and tested in the 4‐to‐1 contraction problem for Stokes flow. The comparison shows significant differences among them, which are not present when the velocity–pressure formulation is used.To provide a better understanding of the phenomenon, several variants of the previous elements are introduced, obtained by either changing the pressure space or by enriching the stress space with bubble functions. The formulation exhibits a strong sensitivity to the first alternative, while the second produces only a minor effect. These observations are confirmed by a convergence test effected on a regular problem with the explicit analytical solution. Also, as a result of the whole comparison, the P 2+/P 2+/P1element looks promising for three

ISSN:0271-2091    

DOI:10.1002/fld.1650170202

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA new flux vector splitting scheme has been suggested in this paper. This scheme uses the velocity component normal to the volume interface as the characteristic speed and yields the vanishing individual mass flux at the stagnation. The numerical dissipation for the mass and momentum equations also vanishes with the Mach number approaching zero. One of the diffusive terms of the energy equation does not vanish. But the low numerical diffusion for viscous flows may be ensured by using higher‐order differencing. The scheme is very simple and easy to be implemented. The scheme has been applied to solve the one dimensional (1D) and multidimensional Euler equations. The solutions are monotone and the normal shock wave profiles are crisp. For a 1D shock tube problem with the shock and the contact discontinuities, the present scheme and Roe scheme give very similar results, which are the best compared with those from Van Leer scheme and Liou–Steffen's advection upstream splitting method (AUSM) scheme. For the multidimensional transonic flows, the sharp monotone normal shock wave profiles with mostly one transition zone are obtained. The results are compared with those from Van Leer scheme, AUSM and also with the experim

ISSN:0271-2091    

DOI:10.1002/fld.1650170203

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA simple and efficient approximate numerical technique is presented to obtain solutions to a wide class of two‐point boundary value similarity problems in fluid mechanics. This technique is based on the common finite difference method with central differencing, a tridiagonal matrix manipulation and an iterative procedure. The technique described in this paper has been successfully applied to three different representative similarity problems of fluid mechanics. Each one of these problems is described by a coupled, non‐linear system of three ordinary differential equations and has already been solved elsewhere using a different numerical method. So, the obtained numerical results, by our efficient numerical technique, permit a comparative study and show the accuracy and the effectiveness of this techni

ISSN:0271-2091    

DOI:10.1002/fld.1650170204

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper describes a new method to generate surface grids over complex configurations defined by a geometric generation system. The scheme is designed for direct utilization of the surface definition provided by a geometric modeller based on a boundary representation (the so‐called B‐rep modeller). Thus, the conversion of the geometric representation for the surface grid generator is not required. Consequently, this technique eliminates not only laborious tedium in the conversion of data, but also errors in the representation of the surface induced in the process of the conversion.The proposed method is accomplished over several stages. First, the triangulation is performed on the surface of the geometry, on which the area to be grided is laid. Then linear partial differential equations are mapped and solved on these triangular elements. Finally, the surface grid is constructed by searching for the contours inside the solution domain. After the co‐ordinate values of the grid points are obtained by a linear interpolation within each triangular element, these values are mapped onto the surface of the geometry through surface parametric functions provided by the B‐rep modeller.An example of generating surface grid over a car configuration is given to illustrate the capability of the

ISSN:0271-2091    

DOI:10.1002/fld.1650170205

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650170201

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY