摘要:

AbstractA methodology for the decomposition of the Crouzeix‐Raviart finite element into six linear subelements is described. The resulting element is shown to satisfy the Brezzi‐Babuška compatibility condition. The error bounds are also established. A comparison in accuracy between this and the standard Crouzeix‐Raviart element is presented for driven cavity flows. Other results include the execution time for the DCR element and the Crouzeix‐Raviart element along with both analytical and numerical integration. It is shown that the decomposed element results in shorter execution times with only marginal changes in

ISSN:0271-2091    

DOI:10.1002/fld.1650130902

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractAn adaptive grid solution procedure is developed for incompressible flow problems in which grid refinement based on an equidistribution law is performed in high‐error‐estimate regions that are flagged from a preliminary coarse grid solution. Solutions on the locally refined and equidistributed meshes are obtained using boundary conditions interpolated from the preliminary coarse grid solution, and solutions on both the refined and coarse grid regions are successively improved using a multigrid approach. For this purpose, suitable correction terms for the coarse grid equations are derived for all variables in the flagged regions. This procedure with Local Adaptation, Multigridding and Equidistribution (LAME) concepts is applied to various flow problems to demonstrate the accuracy improvements obtained using this met

ISSN:0271-2091    

DOI:10.1002/fld.1650130903

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractNumerical entropy generation is studied in the case of steady, subsonic Euler flow along a kinked solid wall. For a standard upwind finite volume discretization the numerical entropy error, a component of the global discretization error, appears to be zeroth‐order in mesh size. Two possible causes of the zeroth‐order entropy error are studied. First an investigation is made of the local truncation error on a kinked grid. Although this error also appears to be zeroth‐order in the neighbourhood of the kink, it probably does not cause the zeroth‐order entropy error. Next a study is made of the existence of a singularity in the exact solution. Probably, the Euler flow solution is singular at the kink in the wall. The form of this likely singularity is unknown. Therefore the construction of a computational method which usesa prioriknowledge about the singularity is not possible. Finally it is shown by numerical experiments that the subsonic Euler flow along a kinked wall still can be computed with vanishing entropy errors by using an appropriate sequence of continuously curved walls which converge to the kinked wall in the limit of zero mes

ISSN:0271-2091    

DOI:10.1002/fld.1650130904

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA method of efficiently computing turbulent compressible flow over complex two‐dimensional configurations is presented. The method makes use of fully unstructured meshes throughout the entire flow field, thus enabling the treatment of arbitrarily complex geometries and the use of adaptive meshing techniques throughout both viscous and inviscid regions of the flow field. Mesh generation is based on a locally mapped Delaunay technique in order to generate unstructured meshes with highly stretched elements in the viscous regions. The flow equations are discretized using a finite element Navier‐Stokes solver, and rapid convergence to steady state is achieved using an unstructured multigrid algorithm. Turbulence modelling is performed using an inexpensive algebraic model, implemented for use on unstructured and adaptive meshes. Compressible turbulent flow solutions about multiple‐element aerofoil geometries are computed and compared with experimental

ISSN:0271-2091    

DOI:10.1002/fld.1650130905

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA numerical code based on the upwind TVD scheme for simulating the various reflection processes of a planar shock wave over a concave or convex double wedge has been developed. The numerical results were compared with actual experiments and excellent agreement was obtained. The excellent agreement serves also as a validation of the shock‐capturing performance of the numerical schem

ISSN:0271-2091    

DOI:10.1002/fld.1650130906

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA new method is introduced to solve potential flow problems around axisymmetric bodies. The approach relies on expressing the infinite series expansion of the Laplace equation solution in terms of a finite sum which preserves the Laplace solution for the potential function under a Neumann‐type boundary condition. Then the coefficients of the finite sum are calculated in a least squares approximation sense using the Gram‐Schmidt orthonormalization method. Sample benchmark problems are presented and discussed in some detail. The solutions are accurate and converged faster when a rather small number of terms were used. The method is simple and can be easily program

ISSN:0271-2091    

DOI:10.1002/fld.1650130907

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe present work is concerned with the numerical calculation of the turbulent flow field around the stern of ship models. The finite volume approximation is employed to solve the Reynolds equations in the physical domain using a body‐fitted, locally orthogonal curvilinear co‐ordinate system. The Reynolds stresses are modelled according to the standardk‐ε turbulence model. Various numerical schemes (i.e. hybrid, skew upwind and central differencing) are examined and grid dependence tests have been performed to compare calculated with experimental results. Moreover, a direct solution of the momentum equations within the near‐wall region is tried to avoid the disadvantages of the wall function approach. Comparisons between calculations and measurements are made for two ship models, i.e. the SSPA and HS

ISSN:0271-2091    

DOI:10.1002/fld.1650130908

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650130909

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650130901

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY