The heat transfer performance of the superhydrophobic surfaces with wear resistance

Superhydrophobic surfaces are widely used in self-cleaning, anti-icing and enhancing condensation heat transfer. Here, the superhydrophobic surface was prepared with micro-nano structure to enhance steam condensation heat transfer, while maintaining good mechanical stability. The influence of different wettability surfaces, different microstructure substrates and surface subcooling on the droplet dynamics and heat transfer performance of condensate droplets were studied by visualization techniques. The results demonstrate that the contact angle of the coated pyramid surface can still reach similar to 135 degrees after 30 abrasion cycles, this is because the microstructure pyramid can well protect the hydrophobic particles embedded in these surfaces. The heat flux of the coated pyramid surface (with the base surface etched for 30 min) increased by 38.8 % and 116 %, compared with the coated micropillar surface and the hydrophilic surface, respectively, at high subcooling (similar to 17 K). This is mainly because the condensed droplets on the coated pyramid surface (30 min) have better fluidity. It is worth noting that the heat flux of the worn surface is 86.47 %similar to 103.63 % higher than that of the hydrophilic surface at high subcooling (similar to 17 K), due to better wear resistance provided by the micro pyramid structure. These findings provide a theoretical and experimental guidance for the development of condensing surfaces to enhance heat transfer.