For Czochralski (Cz) growth of silicon single crystals, 3D unsteady simulations of the oxygen transport in the turbulent melt flow were conducted using a new formulation for the evaporation at the free surface found by Sakai et al. [Electrochem. Solid-State Lett. 5 (8) (2002) G72]. Compared with 2D results from literature, the computed oxygen concentration now fits the experimental data better, showing lower values in the critical region beneath the crystal than in previous simulations, which mostly arises from the more accurate prediction of the flow field. Further computations of Cz configurations show how the oxygen distribution can be influenced by rotation of the crucible and crystal. (C) 2007 Elsevier B.V. All rights reserved.