Nanoscale Surface Modification Techniques for Pool Boiling EnhancementA Critical Review and Future Directions

New discoveries presented in the last decade for enhancing boiling performance utilizing nanoscale structures on surfaces are critically examined in this paper. Since the mechanism for such a phenomenon is not fully understood, this review mainly focuses on the experimental studies reported in the literature on the boiling phenomena on nanostructures, and implementation of nanostructures on various substrates. The paper also focuses on the interpretation of underlying phenomena for enhancing the boiling performance. The main influencing parameter in controlling is seen as the change in the surface energy of the boiling surface, which is characterized by the contact angle of the liquid and vapor phase interface at the heating surface. The nanostructures are seen to alter the contact angle. Design consideration and theoretical developments are also discussed, followed by practical aspects of nanostructure manufacturing. The issues related to performance, ease of fabrication, and durability (whenever available) are reviewed and recommendations are made for future research in this emerging area.