Heat transfer in a rotating two-pass square channel with 180degrees sharp turns was numerically simulated by using the large eddy simulation with a Lagrangian dynamic subgrid-scale model. In the stationary condition, the heat transfer in and after the turn was increased due to the flow impingement, the flow separation and reattachment, and the reversed flow at the second outer corner. In the rotating condition, the high momentum fluid on the upstream pressure side formed one strong vortex in the turn that transported the high momentum and low temperature fluid to the suction surface side where the heat transfer became high. (C) 2003 Elsevier Ltd. All rights reserved.