Experimental validation of flow and tracer-dispersion models in a four-strand billet-casting tundish

Abstract

An exhaustive literature search indicates that, despite a large number of physical and mathematical model studies, very little efforts have been made to assess predicted flow and turbulence parameters in the tundish directly against equivalent experimental measurements until recently. Consequently, experimental measurements on the instantaneous velocity and residence-time distribution (RTD) were carried out in a scaled water model of a four-strand billet-casting tundish. While particle-image velocimetry (PIV) was applied to measure instantaneous flow, the electrical-conductivity measurement technique was applied to determine the RTD. Through PIV, the mean and the fluctuating components were derived along the central vertical plane of the tundish at two different liquid inflow rates: 1.55×10⁻⁴ m³/s and 3.10×10⁻⁴ m³/s, respectively. Similarly, RTD curves were obtained for tundish operations without and with a dam+turbulence inhibitor device (TID). Parallel to these operations, the flow and tracer dispersion were numerically predicted by FLUENT®. It is shown that the predicted time-average velocity components within the bath bear excellent correspondence with PIV measurements. On the assumption of isotropic fluctuations, turbulent kinetic energy was derived from experimental measurements, which agreed moderately with predictions. Furthermore, the experimentally derived fluctuating velocity components were compared with those obtained from the Reynolds stress model. This indicated very reasonable agreement between measurement and predictions (within ±20 pct). Despite such a difference, however, the extent of agreement between the measured and computed C curves was found to be excellent.