Heat transfer in fully developed turbulent channel flow with streamwise traveling wave-like wall deformation

Abstract

The dissimilarity between the momentum and heat transfer due to streamwise traveling wave-like wall deformation in turbulent channel flows is investigated through direct numerical simulations. The flow rate is kept constant, and the bulk Reynolds number is Reb = 5600. A constant temperature difference condition is imposed on the channel walls. The parametric study shows that the heat transfer is enhanced when the wave travels in the upstream direction. The maximum analogy factor is found to be 1.13, i.e., 13% enhancement of heat transfer under a given pressure gradient, when the wall deformation amplitude is large and the wall deformation period is short. An analysis using the identity equations for the drag and the heat transfer with a three component decomposition reveals that the random component plays an important role in the enhancement of the heat transfer.