Enhancement of Heat Transfer during Pool Boiling of Distilled Water by Electron-Beam Surface Modification

This study presents the results of an experimental investigation of the effect of electron-beam surface modification on heat transfer during nucleate pool boiling of distilled water at atmospheric pressure. The relevance of the research is driven by the need to improve the efficiency of cooling systems operating under high heat flux conditions. Copper surfaces with various microrelief geometries fabricated by electron-beam processing using the Surfi-Sculpt technique were employed as test specimens. Three types of modified surfaces were produced: star-shaped structures generated using both the forward and reverse electron-beam scanning modes, and a surface with a linear structure. Boiling curves and heat transfer coefficient versus heat flux relationships were obtained for all investigated samples. The results demonstrated that electron-beam surface modification significantly enhances boiling heat transfer compared with a smooth copper surface. For all modified specimens, the boiling curves shifted toward lower wall superheats, accompanied by an increase in the heat transfer coefficient and critical heat flux. It was shown that the heat transfer performance is strongly influenced by the geometry of the fabricated microrelief, which affects the density of active nucleation sites as well as the liquid supply and vapor removal mechanisms. The obtained results confirm the potential of electron-beam processing as an effective approach for the development of high-performance boiling heat transfer surfaces.