摘要:

A numerical method for the computation of topological and geometric properties of iso-surfaces with and without boundaries developed by the authors is applied to randomly generated surfaces and surfaces embedded in numerical solutions of the Navier-Stokes equations. The Euler number of level surfaces corresponding to site percolation is shown to change drastically at the critical value for percolation. Numerical solutions of the Navier-Stokes equations are used to investigate the topological and geometric effects of vortex stretching and viscosity on iso-surfaces of enstrophy, dissipation rate and kinetic energy.

ISSN:1061-8562    

DOI:10.1080/10618569708940802

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This paper presents an adaptive finite element method for solving incompressible turbulent flows using the k-e model of turbulence. Solutions are obtained in primitive variables using a highly accurate quadratic finite element on unstructured grids. Turbulence is modeled using the k-e model. A projection error estimator is presented that takes into account the relative importance of the errors in velocity, pressure, turbulence variables and eddy viscosity. The methodology is verified by solving problems with known analytical solutions. The method is then applied to turbulent free shear flows and predictions are compared to experiment.

ISSN:1061-8562    

DOI:10.1080/10618569708940803

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

A discrete numerical method based on a molecular approach has been used as an alternative technique for the study of liquid drop dynamics. The Weber number and the Impact number are found to be the key parameters that determine the outcome of collision of two liquid droplets. This study confirms the experimental fact that the number of daughter droplets resulting from the collision of two droplets increases with the Impact number for a large Weber number. The shapes of the droplets at different phases during collision are in accord with the experimental observation.

ISSN:1061-8562    

DOI:10.1080/10618569708940804

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

We investigate the vortical flow structure which has evolved in a rectangular cavity defined by a depth-to-width aspect ratio of 1:1 and a span-to-width aspect ratio of 3:1. The vortical system of interest consists of a dominant eddy, secondary motions, and spiraling spanwise motion. The objective of this study was to broaden knowledge of: 1) how the Taylor-Görtler vortices emerge and modify the flow structure; 2) why the left vortex differs from its right counterpart in each unsymmetric pair of TGL vortices. Most importantly, the intent of this study is to discuss the formation of flow instabilities from the energy standpoint.

ISSN:1061-8562    

DOI:10.1080/10618569708940805

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor