A three-dimensional simulation of coupled turbulent flow and macroscopic solidification heat transfer for continuous slab casters

Abstract

A numerical investigation was conducted for exploring the steady state transport phenomena of turbulent flow, heat transfer and macroscopic solidification in a continuous stainless steel slab caster. The numerical model is based on a generalized transport equation applicable to all the three regions, namely liquid, mushy and solid, which exist in a slab caster. The turbulence effects on the transport equations were taken into account using a low-Reynolds number k- ε turbulence model. The solidification of molten steel was modeled through the implementation of the popular enthalpy-porosity technique. A control volume based finite-difference scheme was used to solve the modeled equations on a staggered grid arrangement. A series of simulations was carried out to investigate the effects of the casting speed, the delivered superheat and the immersion depth of the twin-ported submerged entry nozzle (SEN) on the velocity and temperature distributions and on the extent of the solidified and mushy regions on the narrow and broad faces of the caster. In the absence of any known experimental data related to velocity profiles in a slab caster, the numerical predictions of the solidified profile on a caster's narrow face were compared with limited experimental data and a good agreement was found.