Comparison of turbulence models for natural convection in enclosures: applications to crystal growth processes

This study examines the relative performance of four turbulence models for their possible application in simulating turbulent flow and heat transfer in the Czochralski crystal growth process. These are the standard k - ε model with wall function (Launder, 1978), the low-Reynolds-number k - ε model proposed by Abe and Kondoh (Abe and Kondoh, 1995), the renormalization group κ - ε model of Yakhot et al. (Yakhot et al., 1992) and the algebraic stress model by Gatski and Speziale (Gatski and Speziale, 1993). Attention was given to the renormalization group κ - ε model (RNG) and particularly the algebraic stress model (ASM) because of its nonlinear and nonisotropic properties. In fact, the latter model has been reported to give comparable results to full-scale second moment closures for complicated systems with rotation, body force and mild inhomogeneity. Some of the comparisons were made with experimental measurements of turbulent, high Rayleigh number flows. The RNG and ASM results agree better with the experimental data of Cheesewright et al. (Cheesewright et al., 1986) for the vertical velocity distribution.