Near-wall modelling and free-stream turbulence effects on square cylinder unsteady heat transfer

Unsteady flow passing a heated square cylinder has been investigated using a hybrid LES-RANS approach at a moderate Reynolds number of 22, 050. Two near-wall RANS models are blended smoothly to the LES region. The two models applied have successfully reproduced time- and phase-averaged flow field. Encouraging convective heat transfer has been predicted. An increase in the convective heat flux is found on the cylinder top/bottom surface with imposed free-stream turbulence. More accurate prediction of velocity and Nusselt number profiles has been made by the use of LES-k! model