Molecular dynamics study of explosive boiling on hybrid wettability concave and convex surfaces

Abstract

This paper uses the molecular dynamics (MD) method to study the boiling mechanism of water film explosion on purely wettability surfaces and the effect of hybrid wettability concave and convex surfaces on boiling heat transfer. The results suggest that the water molecules on the strong wettability surface adhere to the solid surface and collide with the solid atoms at high frequencies. However, the water molecules on the weak wettability surface move away from the surface in a disorderly manner. The difference in the motion behavior of water molecules on various wettability heating surfaces makes water films nucleate earlier on hydrophobic surfaces and boil off faster on hydrophilic surfaces. Meanwhile, the explosive boiling process of pure and different hybrid wettability concave and convex surfaces was studied, which indicates that the best heat transfer efficiency of B6 (The convex nanostructures have hydrophobic surfaces on the sides and hydrophilic surfaces on the other parts). B6 has an initial maximum heat flux, maximum initial HTC, and a maximum average heat flux, as well as a lower nucleation temperature and an earlier nucleation time. The reasonable setting of the combination of surface wettability and concave-convex nanostructures benefits the enhancement of explosive boiling heat transfer.