Numerical investigation of mixed convective heat transfer for unsteady turbulent flow over heated blocks in a horizontal channel

The turbulent flow field and heat transfer enhancement of mixed convection in a horizontal block-heated channel was investigated, using the Large Eddy Simulation (LES) and SIMPLE-C method coupled with preconditioned conjugate gradient methods. A rectangular turbulator was mounted in the channel to enhance heat transfer by means of an internal flow modification induced by vortex shedding in this study. The width-to-height ratio of turbulator was changed (0.25, 0.5 and 1.0) with a constant Reynolds number (5000) under various Grashof numbers (0-5.OE+8) for the purpose of investigating the heat transfer performance. The results indicate that the turbulator mounted in cross-flow above an upstream block can effectively enhance the heat transfer performance of mixed convection in the horizontal channel. (C) 2007 Elsevier Masson SAS. All rights reserved.