Transport Phenomena in Stacks of Interrupted Parallel-Plate Surfaces

A scale-up model of interrupted fin surfaces in compact exchanger cores is employed for pressure loss and heat transfer study in a wind tunnel. Offset strip- and slotted-type interruptions are considered together with the plain plate fin for comparison. The physical dimensions of the fin surfaces and enclosing core and the flow rate are varied to closely simulate both the physical and operating conditions in actual compact heat exchangers. It is found that the offset strip fin is superior to both the slotted and plain straight fins in heat transfer/ pressure drop performance. The f and j correlation equations are derived for the offset strip fin cores. Two kinds of performance enhancement are identified and their mechanisms are explored.