Enhanced heat transfer of pulsating flows in a wavy channel

A fully developed convective heat transfer inside a two-dimensional periodically wavy channel is investigated numerically with pulsating flows under a constant wall temperature. It is based on the SIMPLER (semi-implicit method for pressure linked equations revised) algorithm in curvilinear body-fitted coordinates. Calculations are performed with Pr = 0.7, Re = 5-500 on a non-orthogonal non-staggered grid generated by elliptic equations. The effects of pulsatile parameters, such as pulsatile amplitude and frequency on heat transfer and flow friction, are studied. It shows that the vortices sweeping, diminishing and growing up due to pulsating flows enhance fluid pulsating and mixing, and lead to the enhancement of heat transfer. The intensity of heat transfer increases with the increase of Reynolds numbers and amplitudes and is independent of pulsating frequencies. The instantaneous flow resistance and Nusselt numbers present periodical cosine and sine variations, respectively.