Mathematical modelling of flow field in a continuous slab caster tundish including near wall turbulence effects

Abstract

A theoretical model has been proposed in conjunction with a low Reynolds number (K-E) two equation turbulence model to simulate fluid flow phenomena in steel continuous casting (CC) tundish for slabs. It is perceived that locations near the walls and in the vicinity of flow control devices of the tundish, where the liquid velocities are relatively low, the inclusion particles may move the laminar sub-layer and stick to the wall. An attempt has been made to incorporate the near wall effects in a realistic way by employing the concepts of low Reynolds number turbulence model to the present problem. The model, which has been implemented in a FORTRAN 77 code to executable on a personal computer with preferably 256 MB RAM for adequate grid refinement. Computed results describing the flow field and the Residence Time Distribution (RTD) during the steady state operation are presented. The various indexes of residence time such as t(mean) and t(peak) obtained from the RTD curves and used to study the effects of various combinations of flow control devices on the removal of inclusion. The results show that the characteristics of fluid flow behaviour within a tundish can be varied appreciably with the use of flow control devices incorporating near wall effects.