Air-side heat transfer enhancement in plate-fin channel with an airfoil-based self-agitator

Airfoil-based self-agitators (AFAs) were installed in multiple plate-fin channels integrated with cantilever beams. The heat transfer enhancement and pressure drop characteristics of this AFA design were experimentally investigated and compared with the clean channel case. We found that the AFA vibrates periodically and generates vortices, which enhance flow mixing and thus heat transfer performance. A rectangular shaped airfoil-based self-agitator (RAFA) and a delta shaped airfoil-based self-agitator (DAFA) with variable chord lengths were designed to investigate shape and size effects on thermal performance. Measurements were also carried out for DAFAs with different layouts, such as multiple rows of DAFAs installed inside a single channel. For the chosen heat sink and assigned working conditions, the best heat transfer performance was obtained with four rows of DAFAs, which caused an 80% increase in overall Nusselt number over the clean channel at the same Reynolds number and a 50% rejected heat increase at the same pumping power due to the strong longitudinal vortices generated by the presence of the AFAs.