Numerical simulations of isothermal and heated turbulent upflow of a liquid in a vertical concentric annular channel with its inner wall heated were carried out. Near-wall two-equation turbulence models were used to close the Reynolds-averaged momentum and thermal energy equations. In addition, a near-wall explicit turbulent heat flux model was incorporated. The results reported include mean and turbulence quantities. Comparison with our measurements reported in Part I of this two-part paper is presented. The Reynolds number at the channel inlet ranged from 22 800 to 46 400, and the range of Gr/Re-2 at the measurement plane was 0.009-0.078. Buoyancy effects which influenced the velocity and thermal fields were observed in the simulation results as they were in the measurements. (C) 2001 Elsevier Science Ltd. All rights reserved.