TEMPORAL AND SPATIAL-DISTRIBUTION OF HEAT-FLUX IN OSCILLATING FLOW SUBJECTED TO AN AXIAL TEMPERATURE-GRADIENT

The temporal and spatial distribution of heat flux within counter-oscillating slugs of fluids, along which is maintained a constant axial temperature gradient, is examined. It is found that the resultant axial heat flux pulsates at twice the base oscillation frequency and that the time-averaged axial heat flow under tuned conditions is orders of magnitude larger than that present in the absence of oscillations. Such thermal pumping is produced by the time-dependent interaction of a transverse conduction flux, produced by large transverse temperature gradients, with the periodic axial fluid motion.