In the present study, turbulent flow and heat transfer in a square duct with a heated wavy wall are investigated numerically using the Large Eddy Simulation (LES). A thorough validation of the numerical approach is done versus the existing results for both flat-wall square ducts and wavy-wall channels. It is demonstrated that a very good agreement is achieved with the literature in terms of global and local flow and heat transfer parameters.
Heated wavy surfaces of various amplitudes are explored. The results are compared with those for a completely flat duct in terms of the friction factor and Nusselt number. It is shown that the friction factor increases practically linearly with the wave amplitude. On the other hand, the Nusselt number, averaged over the entire duct length, increases more steeply for the relatively small wave amplitude, but almost reaches a plateau for a further increase in the amplitude.