Heat transfer enhancement inside converging-diverging wavy channel by pulsating flow

The fully developed convective heat transfer characteristics inside two-dimensional periodically converging-diverging wavy channel with pulsating flow due to imposed entry pulsating mass flow under constant wall temperature was investigated numerically. Based on SIMPLER algorithm in the curvilinear body-fitted coordinates, the calculations were performed for Pr=0.7, Re=10-1000 on non-orthogonal non-staggered grids which are generated by elliptic equation systems. Effects of Reynolds numbers, pulsating amplitude and frequency on heat transfer enhancement and flow friction were studied. The results show that, in the steady regime, flow separates after Re>40, and becomes unsteady and chaotic after Re>600. Heat transfer can be enhanced by fluid pulsating and mixing which is caused by the vortices sweeping, diminishing and growing up due to the pulsating flow. The intensity of heat transfer enhancement increases with the increase of Reynolds numbers, pulsating frequency and amplitude. On the other hand, the flow friction varies periodically and sinusoidally with the dimensionless time, while it is independent of the pulsating frequency.