摘要:

AbstractA two‐dimensional (in‐plane) numerical model for surface waves propagation based on the non‐linear dispersive wave approach described by Boussinesq‐type equations, which provide an attractive theory for predicting the depth‐averaged velocity field resulting from that wave‐type propagation in shallow water, is presented. The numerical solution of the corresponding partial differential equations by finite‐difference methods has been the subject of several scientific works. In the present work we propose a new approach to the problem: the spatial discretization of the system composed by the Boussinesq equations is made by a finite element method, making use of the weighted residual technique for the solution approach within each element. The model is validated by comparing numerical results with theoretical solutions and with results obtained e

ISSN:0271-2091    

DOI:10.1002/fld.1650160602

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractStratified and intermittent stratified‐bubble (slug) flows are complex phenomena, often requiring transient 2D and 3D descriptions. This paper presents the physical basis of a new type of multidimensional two‐fluid model, particularly suited for transient flow problems. Important constitutive relations for wall shear stress and interfacial momentum transfer with necessary assumptions and simplifications are discussed. The numerical method is based on an implicit finite difference scheme, solved directly in two steps applying a separate equation for the pressure. The model has been verified through extensive comparisons with available experimental data as well as through comparisons with other mod

ISSN:0271-2091    

DOI:10.1002/fld.1650160603

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA high‐order Godunov‐type scheme based on MUSCL variable extrapolation and slope limiters is presented for the resolution of 2D free‐surface flow equations. In order to apply a finite volume technique of integration over body‐fitted grids, the construction of an approximate Jacobian (Roe type) of the normal flux function is proposed. This procedure allows conservative upwind discretization of the equations for arbitrary cell shapes. The main advantage of the model stems from the adaptability of the grid to the geometry of the problem and the subsequent ability to produce correct results near the boundaries. Verification of the technique is made by comparison with analytical solutions and very good agreement is found. Three cases of rapidly varying two‐dimensional flows are presented to show the efficiency and stability of this method, which contains no terms depending on adjustable parameters. It can be considered well suited for computation of rather complex free‐surface two‐dimensi

ISSN:0271-2091    

DOI:10.1002/fld.1650160604

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractWe describe some experiences using interative solution methods of GMRES type to solve the discretized Navier‐Stokes equations. The discretization combined with a pressure correction scheme leads to two different systems of equations: the momentum equations and the pressure equation. It appears that a fast solution method for the pressure equation is obtained by applying the recently proposed GMRESR method, or GMRES combined with a MILU preconditioner. The diagonally scaled momentum equations are solved by GMRES(m), a restarted version of GMRE

ISSN:0271-2091    

DOI:10.1002/fld.1650160605

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper addresses the implementation of second‐moment closure into a collocated variable arrangement body‐fitted‐finite‐volume scheme in which Cartesian velocity components are used. The methods for avoiding instability in the solution procedure are described. A new method for the treatment of the near‐wall regions for the momentum equations, as well as the prescription of the stresses at the wall, is described in detail. The performance of the methodology is assessed by applying it to two flow situations, where experimental data are available: the flow over a backward step, and the flow through a sinusoidal pipe constriction. The results are very

ISSN:0271-2091    

DOI:10.1002/fld.1650160606

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650160607

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650160601

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY