Numerical Study of Coupled Turbulent Flow and Solidification for Steel Slab Casters

Abstract

A huo-dimenswnol -rim1modeling study was undertaken to account for coupled turbulent Jbw and hent transfer with solidijiurtrurtron in the mold and submold regr'ons of a steel slab caster. Liquid steel is inlmdued in& a waier-ewled mold through a bifiucated submerged entry Mule. Turbulence p h e m m e~ in the meU pool of the cactcr were accounted for, using a modified version of the low-Reymldr-number k-e turbulence model of Lounder and Sharma. nK mushy region solidificcrtion, in the presence of turbulence, was taken into account by modifying the standard enthalpy-porosity technique, which is present& popular for modeling solidijiention problems. nK~~ermrrurpiUary and buoyancy effects / w e been considered in this model to evaluate the influrnces of the liquid &ace tension gradient at the meniscus sudace, ond Mhuol convection on Jlow pattern in the liquid pool. Pammehic studies were urrried out to evaluate the effea3 of typiul variables, such as i& superheat and m ' n g speed, an the m i d Jlow ond heat rronfer &. llw numen'cnl predictr'ons were compared with auoiloble erpcrimntal &a.

Numerical Simulation of the Coupled Turbulent Flow and Macroscopic Solidification in Continuous Casting with Electromagnetic Brake.

“…13,14) The value of d is of the order of 1ϫ10 Ϫ4 m. The constant D 0 is assumed to be 1.8ϫ10 10 in this study. The constant q, introduced to avoid the division by zero, is set at 0.001.…”

“…Thus, it is very difficult to employ the wall functions. In this study, a revised version of low-Reynolds number k-e turbulence model by Launder and Sharma, 15) adopted by a few previous studies, 13,14) is used to consider the turbulent characteristics. A treatment for the release of latent heat in a mushy zone depends on a single-domain-based enthalpy method.…”

“…Thus, a majority of previous work, mainly depending on numerical simulations, has been done on the basis of ultimately limited conditions. [9][10][11][12][13] In particular, two-dimensional analysis has been performed to reduce the computational cost for the analysis of the coupled turbulent flow and solidification. Although the assumption of two-dimensional modeling can be permitted for a round billet caster, the two-dimensional modeling of the square billet or rectangular slab casters has some limitations.…”

Mathematical Modeling of Iron and Steel Making Processes. Mathematical Modeling of Fluid Flow in Continuous Casting.

“…In order to account for the effect of the solid matrix on fluid flow in the mushy region, the enthalpy-porosity technique has been employed, wherein a source term, derived from Darcy's law of porous media, is incorporated in the momentum equation. 72,96) Many researchers model flow and solidification as a coupled problem on a fixed grid. [97][98][99] Although very flexible, this approach is subject to convergence difficulties and requires a fine grid to resolve the thin porous mushy zone next to the thin shell.…”

A Comparison of Numerical Strategies for Modeling the Transport Phenomena in High-Energy Laser Surface Alloying Process

“…In fact, it has been emphasized that depending on the surface tension Reynolds number or Marangoni number (given by the ratio of surface tension gradient force to viscous force as Ma = (ρl ref,v is the characteristic length given by the viscous boundary layer thickness, the other terms are defined later), the transport in the molten pool may become turbulent in nature. As such, it has been observed that in case of surface tension-driven flows, the flow becomes turbulent if the surface tension Reynolds number is greater than 100 (Aboutalebi et al, 1995). It can be shown that typically for a high-power laser melting, the surface tension Reynolds number is much greater than 100.…”