Analysis of turbulent structures in a czochralski system using DNS and LES predictions
Publication date
2008
Document type
Conference paper
Author
Organisational unit
Scopus ID
ISBN
Conference
High Performance Computing in Science and Engineering 2007
Book title
High Performance Computing in Science and Engineering `07 Transactions of the High Performance Computing Center, Stuttgart (HLRS) 2007
First page
371
Last page
386
Part of the university bibliography
✅
Abstract
A DNS of the turbulent flow and heat transfer in an idealized Czochralski configuration was conducted using a very fine grid. The results show the irregular forming of buoyant thermal plumes as well as the occurrence of a large, stable vortical structure in the bulk of the melt. In the averaged flow field a Bénard-cell-like pattern can be recognized. The DNS data served also as a reference for the validation of the LES method. The LES computations were conducted using different grid sizes, SGS models, and discretization methods. For relatively fine grids and central differences, the results agree very well with the DNS. Using an upwind discretization introduces numerical errors. In combination with coarser grids, this leads to large deviations and even qualitative differences. However, overall the computational effort could be reduced significantly by LES. Thus a compromise between accuracy achieved and effort required has to be found.
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Not applicable (or unknown)
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