Extraordinary drag-reducing effect of a superhydrophobic coating on a macroscopic model ship at high speed

Abstract

We have fabricated a self-cleaning coating on a model ship with a large and curved surface by electroless deposition of gold aggregates, and the superhydrophobic model ship exhibited a remarkable drag reduction of 38.5% at a velocity of 0.46 m s⁻¹. The as-prepared coating exhibits excellent superhydrophobic properties, with a contact angle as high as 159.7°. To rule out the influence of wetting area differences between superhydrophobic coated materials and normal materials, we modified the large curved surface of a model ship with the self-cleaning coating and investigated its drag reducing properties at high speed. The results showed that the superhydrophobic coating took effect in reducing drag; the mechanism of the drag reduction is discussed based on the plastron effect and Newton's law of viscosity.