摘要:

AbstractThe paper deals with the linear stability analysis of laminar flow of a viscous fluid in a rotating porous medium in the form of an annulus bounded by two concentric circular impermeable cylinders. The usual no‐slip condition is imposed at both the boundaries. The resulting sixth order boundary value, eigenvalue problem has been solved numerically for the small‐gap case by the Runge‐Kutta‐Gill method, assuming that the marginal state is stationary. The results of computation reveal that the critical Taylor number increases with decreasing permeability of the medium. The problem is found to reduce to the case of ordinary viscous flow in the annulus obtained by Chandrasekhar,1when the permeability parameter tends

ISSN:0271-2091    

DOI:10.1002/fld.1650040902

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA finite and infinite element model is derived to predict wave patterns around a semi‐infinite breakwater in water of constant depth. Both circular and square meshes of elements are used. The wave theory used is that of Berkhoff. The appropriate boundary conditions for finite and infinite boundaries are described. The singularity in the velocity at the breakwater tip is modelled effectively using the technique of Henshell and Shaw originally developed in elasticity. The results agree well with the analytical solution. In addition the problem of waves incident upon a semi‐infinite breakwater and parabolic shoal, where both diffraction and refraction are present, is solved. There is no analytical solution for this case. The combination of finite and infinite elements is found to be an effective and accurate technique for such probl

ISSN:0271-2091    

DOI:10.1002/fld.1650040903

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractWe consider in this paper the numerical solution of the Falkner‐Skan differential equation, modelling under some similarity assumptions the boundary layer equation. We look for the extremal solution of this third order differential equation. The methods we use are basically the Newton method with a shooting process, which is coupled with a continuation method: they allow us to follow the solution arcs which contain regular and turning point solution

ISSN:0271-2091    

DOI:10.1002/fld.1650040904

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA comprehensive study is presented regarding the numerical stability of the simple and common forward Euler explicit integration technique combined with some common finite difference spatial discretizations applied to the advection‐diffusion equation. One‐dimensional results are obtained using both the matrix method (for several boundary conditions) and the classical von Neumann method of stability analysis and arguments presented showing that the latter is generally to be preferred, regardless of the type of boundary conditions. The less‐well‐known Godunov‐Ryabenkii theory is also applied for a particular (Robin) boundary condition. After verifying portions of the one‐dimensional theory with some numerical results, the stabilities of the two‐ and three‐dimensional equations are addressed using the von Neumann method and results presented in the form of a new stability theorem. Extension of a useful scheme from one dimension, where the pure advection limit is known variously as Leith's method or a Lax‐Wendroff method, to many dimensions via finite elements is also addressed and some stability

ISSN:0271-2091    

DOI:10.1002/fld.1650040905

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650040906

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650040907

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650040901

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY