Flow boiling in nanochannel with wall structure and hybrid wettability

This study employs molecular dynamics (MD) simulations to investigate liquid argon flow boiling on solid substrates, focusing on how nanostructures and hybrid wettability affect heat transfer performance. It is found that the hydrophilic/hydrophobic hybrid surface can break the liquid near the wall regular flow pattern, thus enhancing the micro convection effect. Hybrid wettability introduced on smooth surfaces improves the average heat flux to a greater extent than on nanostructured surfaces, with increases of 28.6 % and 4.5 %, respectively. For smooth surfaces, the one with 35 % hydrophobic area (A2) demonstrates superior performance, achieving the highest average heat flux and the lowest interfacial thermal resistance, and a nucleation time that is 680 ps faster nucleation time than the fully hydrophilic surface (A1). For nanostructured surfaces with 35 % hydrophobic area (S3), where the tops of the nanopillars and the bottoms of the nanocavities remain hydrophilic, the surface demonstrates optimal heat transfer performance. It achieves the highest average heat flux, the lowest interfacial thermal resistance, and a nucleation time that is 1360 ps earlier than that of a fully hydrophilic smooth surface. This study reveals the potential applications of nanostructures and wettability in thermal management systems and provides important guidance for optimizing boiling heat transfer.