Comparison between standard and renormalization group k-ε models in numerical simulation of swirling flow tundish

Because of the introduction of a cylindrical swirling chamber into a neotype tundish, the Swirling Flow Tundish (SFT), the numerical simulation becomes difficult for this kind of tundish by the standard two-equation k-ε turbulence model. So another kind of k-ε turbulence model, the Renormalization Group (RNG) k-ε turbulence model derived from the theory of renormalization group, was adopted and compared with the standard one. Both of these two kinds of turbulence models were used to simulate the flow patterns in SFT on staggered grid systems based on Finite Volume Method (FVM) with SIMPLER algorithm for steady 3D and incompressible Newtonian turbulent flows. The comparison of simulation results from these two models shows that the RNG k-ε turbulence model for SFT leads quicker convergence than the standard one. Unsymmetrical flow patterns were obtained and the grid independence of this mathematical model for SFT was also discussed. The theoretical analyses of forces on particle, turbulent kinetic energy distribution and lower flow velocity behind dam and weir show that there will be a good effect for non-metal inclusion aggregation and separation with the swirling chamber.