Microstructured Surfaces for Single-Phase Jet Impingement Heat Transfer Enhancement

An experimental investigation was conducted to examine the use of microstructured surfaces to enhance jet impingement heat transfer. Three microstructured surfaces were evaluated: a microfinned surface, a microporous coating, and a spray pyrolysis coating. The performance of these surface coatings/structures was compared to the performance of simple surface roughening techniques and millimeter-scale finned surfaces. Experiments were conducted using water in both the free- and submerged-jet configurations at Reynolds numbers ranging from 3300 to 18,700. At higher Reynolds numbers, the microstructured surfaces were found to increase Nusselt numbers by 130% and 100% in the free- and submerged-jet configurations, respectively. Potential enhancement mechanisms due to the microstructured surfaces are discussed for each configuration. Finally, an analysis was conducted to assess the impacts of cooling a power electronic module via a jet impingement scheme utilizing microfinned surfaces.