VOEST‐ALPINE Industrieanlagenbau (VAI) and VOEST‐ALPINE Stahl Linz (VASL), in cooperation with the University of Linz, apply CFD in the field of steelmaking with the motivation to make processes more cost efficient and environmentally compatible, as well as to achieve products of excellent quality. The understanding of existing processes can be substantially improved by numerically simulating fluid flows. This is of special importance for liquid steel flows, which can hardly be observed or investigated by measuring instruments due to the rough ambient circumstances. Simulation of the secondary fume control of electric arc furnaces while taking into account a 3‐dimensional turbulent thermal plume for a 2‐phase flow is performed using k‐ε‐turbulence models flow and an Euler‐Lagrange approach for the particle transport. The results include an optimized air flow design at the inlet of the building and at the outlet through the roof as well as minimized blowing power. The modeling of the steel flow in converters including bottom and side blowing using an Euler‐Lagrange formulation for the calculation of the two‐phase flow and a suited surface model for the iron‐slag‐gas interface. Optimized nozzle configurations and thus shorter process times are achieved.

In this paper a mathematical model for the viscose wet spinning process is presented: We consider a single fibre, which is produced by pressing a basic solution of viscose into a bath containing sulphuric acid. H 2 SO 4 diffuses into the viscose solution and reacts with the natrium hydroxide so that a solidifying fibre is formed which is pulled through the bath by drives. Due to the movement of the fibre and of diffusive transport of sulphuric acid into the fibre velocity and concentration boundary layers develop. Starting from the laminar boundary layer equations we investigate the flow and concentration fields in the bath induced by the fibre utilizing the Local Non-Similarity method. Mass transfer in the fibre is modelled by transport equations for sulphuric acid and natrium hydroxide taking into account the neutralization reaction. The model of the fibre is coupled to the bath phase model by appropriate boundary conditions for the mass flow density and the chemical potential of sulphuric acid. The non-constant diameter of the fibre is taken into account by a perturbation approach.

Evaporation coolers are commonly used to cool hot off-gases by injecting water droplets, which vaporize and thus cool the off-gas so that it can be filtered in the next process step. In this paper the flow and heat and mass transfer in a full scale industrial evaporation cooler are predicted with CFD methods. Three different configurations are compared and evaluated with respect to the flow homogeneity at the spray nozzle plane. In addition, the cold air flow without droplet evaporation in a lab scale model is investigated with CFD as well as PIV (particle image velocimetry) measurements and comparisons are given. In the CFD simulation model all phases involved (off-gas, water droplets, water vapor and dust) are considered. Water droplets and the dust phase are modelled by an Euler/Lagrangian dispersed phase model which allows for a phase change from water droplets to vapor. The mass fraction of water vapor is computed by a diffusion/convection equation. The equations of the Eulerian and Lagrangian phases are fully coupled (the influence of the dispersed phases on the continuous phases and the phase change from water droplets to vapor is realized by appropriate source terms in the Eulerian phase equations). Turbulent particle dispersion is modelled by a stochastic tracking technique.