This paper deals with a Computational Fluid Dynamic contribution to a design procedure for discs and doughnuts extraction columns. The approach can be considered as a numerical alternative to experimental determinations of average hydrodynamic characteristics involved in the phenomenological and transport models used in order to design these contactors. Simulations are carried out by the ESTET calculation code coupled to the k - epsilon turbulent model, for steady-state regimes, and for pulsed flow regimes. In the case of the steady-state regime, correlations between turbulent characteristics of the steady flow and pressure drop in the column with geometrical parameters and dynamic condition are established. The numerical results are in very good agreement with the experimental ones available. In the case of the pulsed flow regime, for which 24 different combinations of geometrical and pulsation parameters have been examined, the results presented consist of the averages over a pulsation cycle of hydrodynamic and mixing characteristics correlated to the pulsation amplitude and frequency, the distance between disc and doughnut and the open free area of the internals. The numerical results are also in fairly good agreement with the experimental ones available.