Flow and Heat Transfer Characteristics of Dimpled Multilouvered Fins

A new fin geometry approximating a dimpled louver in a multilouver configuration under a fully developed flow assumption is investigated. The calculations are conducted on three fin configurations. Cases I and 2 investigate the effect of imprint diameter, whereas Case 3 investigates the effect of introducing a perforation in the dimple imprint. It is established that the dimple imprint diameter has a minimal effect on the flow and heat transfer. However, the introduction of the perforation in the dimple changes the flow and heat transfer profoundly on the dimple side of the fin by eliminating any recirculation regions in the dimple and generating higher intensity vortical structures. The introduction of the perforation increases the heat transfer coefficient between 12-50% with a corresponding increase of 15-60% in the friction coefficient.