Prediction Of Flow Field And Heat Transfer In Channels In Parallel-Mode Rotation At High Rotation And Buoyancy Numbers

This study attempts to understand one of the most fundamental and challenging problems in fluid flow and heat transfer for rotating machines. The study focuses on electric generators for high energy density applications, which employ rotating cooling channels so that materials do not fail under high temperature and high stress environment. Prediction of fluid flow and heat transfer inside internal cooling channels that rotate at high rotation number (Ro) and high wall heat flux similar to those that are existing in generator rotors is the main focus of this study. Rotation, buoyancy and boundary conditions affect the flow inside theses channels. Increasing Ro is one approach to increase heat transfer rate. A fully computational approach is employed in this study. RSM with enhanced near wall treatment is validated against available experimental data (which are primarily at low rotation and buoyancy numbers). The model was then used for cases with high Ro (as much as 0.35) and high wall heat flux. Particular attention is given to how turbulence intensity, Reynolds stresses and transport are affected by Coriolis and buoyancy/centrifugal forces caused by high levels of Ro and wall heat flux. Variations of flow total pressure along the rotating channel are also predicted. The results obtained are explained in view of physical interpretation of Coriolis and centrifugal forces. © 2004 by the American Institute of Aeronautics and Astronautics, Inc