摘要:

AbstractNew implicit finite difference schemes for solving the time‐dependent incompressible Navier‐Stokes equations using primitive variables and non‐staggered grids are presented in this paper.A prioriestimates for the discrete solution of the methods are obtained. Employing the operator approach, some requirements on the difference operators of the scheme are formulated in order to derive a scheme which is essentially consistent with the initial differential equations. The operators of the scheme inherit the fundamental properties of the corresponding differential operators and this allowsa prioriestimates for the discrete solution to be obtained. The estimate is similar to the corresponding one for the solution of the differential problem and guarantees boundedness of the solution. To derive the consistent scheme, special approximations for convective terms and div and grad operators are employed. Two variants of time discretization by the operator‐splitting technique are considered and compared. It is shown that the derived scheme has a very weak restriction on the time step size. A lid‐driven cavity flow has been predicted to examine the stability and accuracy of the schemes for Reynolds number up to 3200 on the sequence of grids with 21 × 21, 41 × 41, 81 × 81 and 161 × 16

ISSN:0271-2091    

DOI:10.1002/fld.1650210802

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractIn this paper, generalized 2D shallow sea dynamic equations in movable curvilinear co‐ordinates are derived. Through a differential co‐ordinate transformation a self‐adaptive grid is proposed to treat a continuously deforming lateral boundary and a kinematical boundary condition is adopted. The self‐adaptive grid method (SAM) is used to simulate numerically the storm surge flooding in the Bohai Sea on 23 April 1969, which was one of the largest storm surge inundations i

ISSN:0271-2091    

DOI:10.1002/fld.1650210803

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractNumerical solutions using the SIMPLE algorithms for laminar flow over a backward‐facing step are presented. Five differencing schemes were used: hybrid; quadratic upwind (QUICK); second‐order upwind (SOUD); central‐differencing and a novel scheme named second‐order upwind biased (SOUBD). The SOUBD scheme is shown to be part of a family of schemes which include the central‐differencing, SOUD and QUICK schemes for uniform grids. The results of the backward‐facing step problem are presented and are compared with other numerical solutions and experimental data to evaluate the accuracy of the differencing schemes. The accuracy of the differencing schemes was ascertained by using uniform grids of various grid densities. The QUICK, SOUBD and SOUD schemes gave very similar accurate results. The hybrid scheme suffered from excessive diffusion except for the finest grids and the central‐differencing scheme only converged for the

ISSN:0271-2091    

DOI:10.1002/fld.1650210804

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe aim of this work is to present a new numerical method to compute turbulent flows in complex configurations. With this in view, ak‐ϵ model with wall functions has been introduced in a mixed finite volume/finite element method. The numerical method has been developed to deal with compressible flows but is also able to compute nearly incompressible flows. The physical model and the numerical method are first described, then validation results for an incompressible flow over a backward‐facing step and for a supersonic flow over a compression ramp are presented. Comparisons are performed with experimental data and with other numerical results. These simulations show the ability of the present method to predict turbulent flows, and this method will be applied to simulate complex industrial flows (flow inside the combustion chamber of gas turbine engines). The main goal of this paper is not to test turbulence models, but to show that this numerical method is a solid base to introduce more sophisticated turbulence m

ISSN:0271-2091    

DOI:10.1002/fld.1650210805

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractIn this paper, four quadratic hexahedron elements are considered and assessed for analysis of an incompressible viscous flow underlying the mixed finite element method. We classify the investigated elements as multivariant and univariant finite elements. With the same number of pressure unknowns, multivariant elements are more constrained when the number of elements per side is larger than 10, as compared with that of continuous pressure elements. In multivariant eléments, the coding is complicated by the appearance of restricted degrees of freedom at mid‐face and mid‐edge nodes. The comparison consequently should be made via numerical example against the analytical pro

ISSN:0271-2091    

DOI:10.1002/fld.1650210806

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650210807

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650210801

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY