Accuracy in evaluating heat transfer coefficient by RANS CFD simulations in a rectangular channel with high aspect ratio - Part 1: benchmark on a channel with plane walls

Computational Fluid-Dynamics (CFD) simulations are widely used for designing components and devices for heat transfer enhancement, and to this end the Reynolds Averaged Navier-Stokes (RANS) equations are often chosen, as they are computationally efficient. In this paper, several numerical simulations have been carried out on convective heat transfer of an air flow through a rectangular channel of 1:10 aspect ratio, 120 mm wide, 840 mm long. Numerical results have been compared to analytical values and experimental data. The configuration of the described numerical model will be used as starting point for detailed investigations of fluid-dynamic and thermal performances of ribbed channels in further analysis.