ON THE NUMERICAL COMPUTATION OF TURBULENT FLUID-FLOW IN CAS STEELMAKING OPERATIONS

Mathematical modelling of turbulent fluid flow in the composition adju stment by sealed (CAS) argon bubbling steelmaking operation has been r eassessed. Toward this end, a quasi-single phase calculation procedure embodying the standard coefficient two-equation k - epsilon turbulenc e model of Launder and Spalding has been applied. It is shown that num erically predicted flow patterns in the CAS reactor vessel depend stro ngly on (i) numerical grid distribution in the flow domain and (ii) ap propriate modelling of turbulence parameters in the vicinity of the ba ffle wall. Provided a sufficiently fine grid is used for the numerical solution together with customary wall functions for flow and turbulen ce parameters (at the baffle wall as well as at the vessel side wall a nd bottom surface), quasi-single phase modelling procedure embodying s tandard coefficients for the k - epsilon model produces estimates of f low variables, which are very similar to those derived via the PHOENIC S-based Eulerian two fluid computational procedure. Present prediction s compare reasonably well with experimental measurements reported prev iously by the present authors.