Finite element solution of three-dimensional turbulent flows applied to mold-filling problems

✍ Scribed by F. Ilinca; J.-F. Hétu

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 352 KB
• Volume: 34
• Category: Article
• ISSN: 0271-2091
• DOI: 10.1002/1097-0363(20001230)34:8<729::aid-fld79>3.0.co;2-p

✦ Synopsis

This paper presents a finite element solution algorithm for three-dimensional isothermal turbulent flows for mold-filling applications. The problems of interest present unusual challenges for both the physical modelling and the solution algorithm. High-Reynolds number transient turbulent flows with free surfaces have to be computed on complex three-dimensional geometries. In this work, a segregated algorithm is used to solve the Navier-Stokes, turbulence and front-tracking equations. The streamline -upwind/ Petrov-Galerkin method is used to obtain stable solutions to convection-dominated problems. Turbulence is modelled using either a one-equation turbulence model or the s-m two-equation model with wall functions. Turbulence equations are solved for the natural logarithm of the turbulence variables. The change of dependent variables allows for a robust solution algorithm and good predictions even on coarse meshes. This is very important in the case of large three-dimensional applications for which highly refined meshes result in untreatable large numbers of elements. The position of the flow front in the mold cavity is computed using a level set approach. Finally, equations are integrated in time using an implicit Euler scheme. The methodology presents the robustness and cost effectiveness needed to tackle complex industrial applications.