Heat sinks with fluted and wavy plate fins in natural and low-velocity forced convection

The effect on heat transfer of geometrically rearranging the surface area of a finned heat sink is investigated. Novel heat sinks with fluted and wavy plate fin configurations are designed and fabricated together with conventional longitudinal-plate and pin fin heat sinks. The experimental apparatus, consisting of the guard heater assembly, isolation chamber, wind tunnel, and data acquisition instrumentation, is described. The thermal performance of the novel and conventional heat sinks is measured and compared for the horizontal and vertical base plate orientations under natural and low-velocity forced convection conditions. Results, presented as the Nusselt number against the Rayleigh or Reynolds numbers, reveal that the pin fin heat sink generally outperforms the other heat sinks, when the heat sink surface area is held constant. A significant effect on heat transfer of the orientation of the forced flow with respect to the buoyancy flow is observed. Overall, the novel heat sink designs do not yield significantly better thermal performance than an optimized conventional longitudinal-plate heat sink.