An improved turbulence model for flow simulation in a continuous casting tundish for slabs

Abstract

A three dimensional mathematical model has been developed based on finite volume technique with improved (K-r) two equation turbulence model to simulate fluid flow phenomena in steel continuous casting (CC) tundish for slabs. Considering the fact that at 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 to the laminar sub-layer and stick to the wall. An attempt has been made to resolve the near wall region in a better way by applying the con-cepts of low Reynolds number turbulence model. The model is designed to be executable in computer systems with minimum 32 MB RAM. Computed results describing the 3-D flow field and the residence time distribution (RTD) during the steady state operation are presented. The math-ematical model is then verified with the published data obtained from full scale water model. The various indexes of residence time such as t ea nd t peak obtained from the RTD curves are used man to analyze the effect 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 considerably with the use of flow control devices incorpor-ating near wall effects.