摘要:

This paper presents a finite element analysis of a fluid-structure interaction problem by the Arbitrary Lagrangian-Eulerian (ALE) method. For the analysis of the Navier-Stokes equation, a fractional step method is used based the linear interpolation functions for both velocity and pressure.

ISSN:1061-8562    

DOI:10.1080/10618569708940792

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

In this paper, an implicit fractional step method for the solution of the two-dimensional, time dependent, incompressible Navier-Stokes equations is presented. The current method was developed for use on an unstructured grid made up of triangles. The basic principles of this method are that the evaluation of the time evolution is split into intermediate steps and that for the spatial discretization of the flow equations, a finite volume discretization for an unstructured triangular mesh is used. The current methodology, which has been tested extensively for steady problems, is now applied for the numerical simulation of unsteady flows. Several cases were tested, such as plane or axisymmetric channels, a square cavity and an axisymmetric stenosis.

ISSN:1061-8562    

DOI:10.1080/10618569708940793

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

A new computation procedure is developed for solving time-accurate, chemically reacting flows over a wide range of Mach numbers. The algorithm is based on scaling the pressure terms in the momentum equations and preconditioning the conservation equations to circumvent numerical difficulties at low Mach numbers. The resulting equations are solved using the lower-upper (LU) factorization method in a fully-coupled manner, with incorporation of a flux-differencing upwind TVD scheme to achieve high-order spatial accuracy. The transient behavior of the modeled system is preserved through implementation of the dual time-stepping integration technique. The capabilities of the scheme are illustrated by applying it to selected problems, including one-dimensional nozzle flows, two-dimensional channel flows, rocket-motor internal flows, and acoustic waves in a porous chamber with surface transpiration.

ISSN:1061-8562    

DOI:10.1080/10618569708940794

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The Reynolds-averaged Navier-Stokes equations are solved in three dimensions. A model accounts for the turbulent character of the flows. The code is described. Attention is focused on the phenomenon of shock-wave/boundary-layer interaction with separation. The experiments conducted in a transonic channel at ONERA, provide an extended data base required for comparison. In order to reduce the computing resources requirements of the code, a selective switch between single and double precision is used for the flow variables. High rates of vectorization, are achieved on a SIEMENS S600/20 computer. The influence of the initial turbulence level on the numerical results is discussed. Validation based on wall pressure distributions, Mach and skin friction contour lines visualizations and on velocity and turbulent energy profiles, shows good agreement with the experimental data. The standard k-εe model gives better predictions than in two dimensions

ISSN:1061-8562    

DOI:10.1080/10618569708940795

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Modification of a two-dimensional isotropic trbulent flow by passage of a weak shock wave was numerically studied by the explicit spectral collocation method with the fourier series in the ranges of M1= 0.14−0.21 and Ms= 1.06−1.14. The density 1 trbulent kinetic energy increased by 10 to 19 % and density fluctuation increased by 14 to 50 % in proportion to the shock wave mach number. The amplification of turbulent kinetic energy did not change by increase of the turbulent Mach number, while that of density fluctuation decreased from1.35 to 1.15%. The argumentation of turbulent kinetic energy appeared at moderate and high wave numbers of energy spectra and resulted in a reduction of the integral scale by3.33 to 5.4%. Modifications mechanisms of turbulent kinetic energy, density fluctuation and vorticity were verified by the transport equations It was shown that the decreased amplification of the density fluctuation In the increased trbulent Mach number attributed to the unchanged production terms and the negative dilatation correlation behind the shock wave.the vorticity-dilatation term was responsible for more than 80 % of the total vorticity production at the shock front.

ISSN:1061-8562    

DOI:10.1080/10618569708956205

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Die swells of fluid flowing through the Monsanto Processability Tester (MPT) are calculated, A finite element method using six-node triangular isoparametric elements is used, to analyze the transient flow motion in which marker particles are introduced to represent the motion. Marker positions are determined by the use of a triangular area co-ordinate system Three simple examples of extruding processes for Newtonian fluid flows are described.

ISSN:1061-8562    

DOI:10.1080/10618569708956206

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor