Pool Boiling Heat Transfer on a Micro‐Structured Copper Oxide Surface with Varying Wettability

Abstract Copper surface is modified to copper oxide surface for high heat flux electronics applications. Copper oxide surface is prepared by chemical etching using NaOH and (NH4)2S2O8. A pool boiling experiment is conducted to investigate the critical heat flux (CHF) and boiling heat transfer coefficient (BHTC). The results indicate that BHTC of all copper oxide surfaces are enhanced remarkably. Bubble dynamics are also analyzed by means of a high‐speed camera. Bubble visualization demonstrates that the active nucleation sites for the copper oxide surfaces are higher than the bare copper surface.