Korean scientists have drawn inspiration from aquatic life and proposed a lubricant-infused slippery surface for ships.
According to the team from Korea Advanced Institute of Science and Technology (KAIST) and Pohang University of Science and Technology (POSTECH), fish and seaweed secrete a layer of mucus to create a slippery surface, reducing their friction as they travel through water.
Mimicking this could result in lubricant-infused surfaces covered with cavities: As the cavities are continuously filled with the lubricant, a layer is formed over the surface.
This could help reduce drag by up to 18% – beneficial for long-distance cargo ships which are known to lose a significant amount of energy due to fluid friction.
As part of their study, the KAIST-POSTECH team looked at the average speed of a cargo ship with realistic material properties and simulated how it behaves under various lubrication setups.
Specifically, they monitored the effects of the open area of the lubricant-filled cavities, as well as the thickness of the cavity lids.
According to the scientists, for larger open areas, the lubricant spreads more than it does with smaller open areas, leading to a slipperier surface.
On the other hand, the lid thickness did not have much of an effect on the slip, though a thicker lid did create a thicker lubricant buildup layer.
The KAIST-POSTECH team is now working on optimizing the lubricant secretion design, and they hope it can be implemented in real-life marine vehicles.
“Our investigation of the hydrodynamics of a lubricant layer and how it results in drag reduction with a slippery surface in a basic configuration has provided significant insight into the benefits of a lubricant-infused surface,” notes KAIST professor Hyung Jin Sung.
“If the present design parameters are adopted, the drag reduction rate will increase significantly.”
Image and content: Shutterstock/AIP Publishing