摘要:

AbstractThis paper presents the parallelization aspects of a solution method for the fully coupled 3D compressible Navier‐Stokes equations. The algorithmic thrust of the approach, embedded in a finite element code NS3D, is the linearization of the governing equations through Newton methods, followed by a fully coupled solution of velocities and pressure at each non‐linear iteration by preconditioned conjugate gradient‐like iterative algorithms. For the matrix assembly, as well as for the linear equation solver, efficient coarse‐grain parallel schemes have been developed for shared memory machines, as well as for networks of workstations, with a moderate number of processors. The parallel iterative schemes, in particular, circumvent some of the difficulties associated with domain decomposition methods, such as geometry bookkeeping and the sometimes drastic convergence slow‐down of partitioned non‐line

ISSN:0271-2091    

DOI:10.1002/fld.1650190402

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractVelocity varies rapidly near sheared boundaries. Therefore in many practical fluid problems it can be inefficient to solve discrete equations with velocity as the dependent variable. Conversely, shear stress varies slowly near sheared boundaries, suggesting that it may be well suited for use as the dependent variable in discrete equations.This paper describes a formulation of the internal mode equations for a three‐dimensional hydrodynamic model using shear stress as the dependent variable. The resulting direct stress solution (DSS), coupled with a spatial discretization using linear finite elements, yields a system matrix that can be set up and solved with the efficiency of a banded matrix with bandwidth 8. If the eddy viscosity distribution is assumed to be piecewise linear over the depth (with an arbitrary number of time‐varying segments), the recovery of velocity from stress can be easily accomplishedin closed form, thereby avoiding any difficulty resulting from the logarithmic singularity in the velocity profile that occurs at a boundary.Results from tidal and wind‐driven test cases with realistic boundary layers are used to demonstrate the accuracy and computational advantages of a DSS formulation versus a standard velocity‐based form

ISSN:0271-2091    

DOI:10.1002/fld.1650190403

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractWe present here a numerical method for solving the free surface flow around a ship at forward speed in calm water. The fluid is assumed to be Newtonian and the Reynolds‐averaged Navier‐Stokes equations are solved by a finite difference method. Modelization of turbulence is achieved by the algebraic model proposed by Baldwin and Lomax. Fully non‐linear free surface conditions are satisfied in the model and a method to avoid the incompatibility between free surface conditions and no‐slip conditions at the waterline is proposed. Numerical results obtained for a Wigley hull are compared with experimental

ISSN:0271-2091    

DOI:10.1002/fld.1650190404

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThis paper deals with the numerical simulation of fluid dynamics using the boundary–domain integral technique (BEM). The steady 2D diffusion–convection equations are discussed and applied to solve the plane Navier‐Stokes equations. A vorticity–velocity formulation has been used. The numerical scheme was tested on the well‐known ‘driven cavity’ problem. Results forRe= 1000 and 10,000 are compared with benchmark solutions. There are also results forRe= 15,000 but they have only qualitative value. The purpose was to show the stability and robustness of the method even when the grid is rela

ISSN:0271-2091    

DOI:10.1002/fld.1650190405

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650190406

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650190407

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650190401

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY