CFD simulation has been presented for the flow in bubble column reactors. P
rocedure has been given for the specification of the drag force and the rad
ial lift force on the basis of drift flux constants. An excellent agreement
has been shown between the experimental and simulated profiles of gas hold
-up and axial liquid velocity. Explanation has been provided for the enhanc
ement in the slip velocity in the heterogeneous regime. (C) 1999 Elsevier S
cience Ltd. All rights reserved.