ISSN:0271-2091    

DOI:10.1002/fld.1650030302

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThis paper derives the convection–diffusion‐reaction equation governing the reaction between the dissolved oxygen in sea‐water and the steel walls of a pulsating crack. By the neglect of the diffusion term it is shown that an exact solution of the convection‐reaction equation can be obtained. A numerical method for the solution of the complete convection–diffusion‐reaction equation is derived by the use of finite differences. The numerical computation of the initial transient and the final periodic steady‐state values is a

ISSN:0271-2091    

DOI:10.1002/fld.1650030303

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA number of contributed solutions to the problem of laminar natural convection in a square cavity have been compared with what is regarded as a solution of high accuracy. The purposes of this exercise have been to confirm the accuracy of the bench mark solution and to provide a basis for the assessment of the various methods and computer codes used to obtain the contributed solutions.

ISSN:0271-2091    

DOI:10.1002/fld.1650030304

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractDetails are given of the computational method used to obtain an accurate solution of the equations describing two‐dimensional natural convection in a square cavity with differentially heated side walls. Second‐order, central difference approximations were used. Mesh refnement and extrapolation led to solutions for 103⩽Ra⩽106which are believed to be accurate to better than 1 per cent at the highest Rayleigh number and down to one‐tenth of that at the low

ISSN:0271-2091    

DOI:10.1002/fld.1650030305

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractDescribed in this paper is a methodology for solving a particular class of optimum design problems in Fluid Mechanics, namely optimum design problems for aerofoils when the corresponding fluid flow is potential. The methods described in this paper operate directly in the physical space, and take advantage of the variational formulation of the partial differential equation modelling the flow. The techniques of optimal control, optimization and the finite element method are used. Numerical examples are also given.

ISSN:0271-2091    

DOI:10.1002/fld.1650030306

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA numerical model is developed to study the interactions of multiple angled jet flows in the inlet port plane of the Detroit Diesel 6V‐92 two‐stroke engine cylinder. The random vortex method is used in two dimensions.Results show axisymmetric swirl initially. As flow develops, the centre of the swirl moves to the mid‐radius region and begins to precess about the cylinder centre. The flow becomes progressively more chaotic as time progr

ISSN:0271-2091    

DOI:10.1002/fld.1650030307

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe use of the velocity‐pressure formulation of the Navier‐Stokes equations for the numerical solution of fluid flow problems is favoured for free‐surface problems, more involved flow configurations, and three‐dimensional flows. Many engineering problems involve such features in addition to strong inertial effects. The computational instabilities arising from central‐difference schemes for the convective terms of the governing equations impose serious limitations on the range of Reynolds numbers that can be investigated by the numerical method. Solutions for higher Reynolds numbers Re>1000 could be reached using upwind‐difference schemes. A comparative study of both schemes using a method based on the primitive variables is presented. The comparison is made for the model problem of the driven flow in a square cavity. Using a central scheme stable solutions of the pressure and velocity fields were obtained for Reynolds numbers up to 5000. The streamfunction and vorticity fields were calculated from the resulting velocity field and compared with previous solutions. It is concluded that total upwind differencing results in a considerable change in the flow pattern due to the false diffusion. For practical calculations, by a proper choice of a small amount of partial upwind differencing the vorticity diffusion near the walls and the global features of the solutions are not sigifican

ISSN:0271-2091    

DOI:10.1002/fld.1650030308

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractUpwind collocation on Hermite cubics is compared to orthogonal collocation with respect to effective diffusion. The one‐dimensional constant coefficient advection‐diffusion equation is employed to this end. The effective diffusion coefficient is determined exactly and is found to be dependent on the nodal solution values. The effective diffusion coefficients of three other upwinding schemes are also presented. Upwind collocation is found to have an effective diffusion coefficient like other upwinding schemes plus an extra term which may enhance or reduce the non‐advective flux, depending on the problem solution and point location within the d

ISSN:0271-2091    

DOI:10.1002/fld.1650030309

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650030310

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650030311

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY