Fluid Flow and Mechanisms of Momentum Transfer in a Six-Strand Tundish

Flow in a six-strand billet tundish, using turbulence inhibitors (TIs), was characterized using inputs of a pulsed tracer and mathematical simulations. It was found that to control turbulence attaining high fluid fractions under plug flow patterns, the key parameter for designing TIs is the dissipation rate of kinetic energy. TI designs that induce steep dissipation gradients are less efficient as flow controllers than those designs that yield more prolonged dissipation gradients from the inhibitor bottom to the bulk flow. A direct relationship between the dissipation of kinetic energy and the linear acceleration of the smallest turbulent eddies in the flow was established through dimensional analysis. The inhibitor with the highest linear accelerations of eddies in the viscous sublayer at the Kolmogorov scale, for a given liquid flow rate, yields the better flow control.