Forced convective heat transfer of 45° rib-roughened fin flows

Heat transfer and pressure drop in dimpled fin channels

“…In particular, due to the lack of sidewall confinements for such a fin channel, the crossstream secondary flows developed in a fully confined rib-roughened duct are not similarly present in the fin channel with two side opens. In a fin channel, the synergetic effects of the weakened streamwise momentum and the absence of sidewalls to guide the rib-wise secondary flows prohibit its HTE effectiveness to reach the level in a ribbed duct with full confinement [3]. Therefore, the comparative results reported by Olsson and Sundén [4] for the fully confined ducts between dimpled and rib-roughened channels are subject to modifications for the likewise enhanced fin channels with two side opens.…”

“…Away from the flow entry region, the side leakages weaken the downstream momentum flux of coolant in the accumulative manner and result in the streamwise decay of local Nusselt numbers. In the attempt to augment the convective performances for such a fin channel, the transverse [2] and 45° [3] ribs are attached on two opposite fins. Local heat transfer enhancements (HTE) induced by these surface ribs are moderated over these ribbed fins as the coolant streams are subject to the accumulative side leakages in the downstream direction [2][3].…”

“…In the attempt to augment the convective performances for such a fin channel, the transverse [2] and 45° [3] ribs are attached on two opposite fins. Local heat transfer enhancements (HTE) induced by these surface ribs are moderated over these ribbed fins as the coolant streams are subject to the accumulative side leakages in the downstream direction [2][3]. In particular, due to the lack of sidewall confinements for such a fin channel, the crossstream secondary flows developed in a fully confined rib-roughened duct are not similarly present in the fin channel with two side opens.…”

Forced Heat Convection of Wavy Fin Channel

“…Augmentations of heat convection for each individual fin channel in a fin array were recently explored using surface ribs [7][8]. Heat transfer rates in the fin channels roughened by 45 0 ribs were about 10~50% higher than those in the smooth-walled channels [8].…”

“…The thickness, gap, pitch and height of fins along with their arrangements were examined in order to study their impacts on the convective capabilities of the fin arrays [2][3][4][5][6]. Augmentations of heat convection for each individual fin channel in a fin array were recently explored using surface ribs [7][8]. Heat transfer rates in the fin channels roughened by 45 0 ribs were about 10~50% higher than those in the smooth-walled channels [8].…”