Turbulence characteristics of a gas-stirred steel bath outside the bubble plume

In order to understand the turbulence characteristic in melts stirred with injected gas, the relations for effective diffusion coefficient, turbulent kinetic energy and mean size of energy containing eddies were derived from the energy equation with an extended flow field for the steel bath, where strong bubble plume and surface currents are present. 67 or 23% of the energy is dissipated in the bubble plume or surface flow zone. An increasing entrainment coefficient leads to higher values of energy dissipation factor, effective diffusion coefficient and mean size of energy containing eddies, but to low degrees of turbulence. With increasing bath aspect ratio the energy dissipation factor increases, but the degree of turbulence decreases. With increasing gas flow rate and bath height the effective diffusion coefficient enlarges. Increasing bath size leads to large mean size of energy containing eddies, which reaches 17% of the bath diameter at high gas flow rates.