Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.
Many researchers have analyzed laminar and turbulent mixed convection in channel flows, however, despite their wide investigations, there are still many cases which are not well understood and difficult to predict. Investigations of heat transfer in the laminar-turbulent (transition) region under the effect of buoyancy (mixed convection) are rather limited. In this paper the results on numerical investigation of the local aiding mixed convection heat transfer in the laminar-turbulent (transition) region in a vertical rectangular channel are presented. Numerical 3D steady state simulations have been performed using Ansys Fluent code in air flow. Modelling has been performed using laminar and transitional (kkl-ω, SST and Re Stress ω) models. Modelling results demonstrate that vortexes exist in the central part of the channel. This makes velocity profiles asymmetrical. The results of numerical modeling have been compared with the results of experiments performed at the same conditions and previous results of 2D numerical modelling using laminar model