Stories
Slash Boxes
Comments

SoylentNews is people

Ships Slide in an Air Envelope

posted by martyb on Friday April 12 2019, @01:33AM   Printer-friendly
from the ship-sliding-away♩♪♫ dept.

Phoenix666 writes:

Phys.org:

ARES ["Air-retaining Surfaces"] studies novel ship coatings, by means of which an air layer is permanently retained under water, which considerably reduces frictional resistance of surfaces. At the same time, release of toxic substances from ship paints and biofilms (fouling) and corrosion is prevented by the air envelope between the ship and the water. Coordinator Thomas Schimmel, who works at the Institute of Applied Physics (APH), the Institute of Nanotechnology (INT), and the Material Research Center for Energy Systems (MZE) of KIT[*], and his group develop air-retaining surfaces under water based on the salvinia effect.

The salvinia effect studied by physicist Professor Thomas Schimmel of KIT and botanist Professor Wilhelm Barthlott of Bonn University in close collaboration with fluid mechanics expert Professor Alfred Lederer of Rostock University enables certain plants, such as the aquatic fern Salvinia molesta, to breathe under water. For this purpose, the aquatic fern is covered with special hairs that resemble small whisks and are characterized by a special chemical heterogeneity: while the individual hairs are water-repellent, each single hair has a water-attracting tip that adheres to water and permanently stabilizes the retained air layer.

[*] KIT: Karlsruhe Institute of Technology.

The project reports the team has demonstrated a 20% reduction in friction between ships and water, an efficiency gain with large implications for global shipping.

Original Submission

 
This discussion has been archived. No new comments can be posted.
Ships Slide in an Air Envelope | Log In/Create an Account | Top | 11 comments | Search Discussion
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.

  • (Score: 3, Interesting) by Runaway1956 on Friday April 12 2019, @02:18AM (1 child)

    by Runaway1956 (2926) Subscriber Badge on Friday April 12 2019, @02:18AM (#828432) Journal

    "We demonstrated that the Air Coating technology reduces friction by about 20%, as friction between ship and water is replaced by friction between ship and air," Thomas Schimmel explains.

    If the craft is moving through the water, with a permanently attached bubble of air under it, then there is no friction between ship and air. The friction is between air and water. Maybe if I read the article a few more times, his phrasing will make sense, but at this point, I see no friction between ship and air, until you get up above the water line.

    Starting Score:    1  point
    Moderation   +1  
       Interesting=1, Total=1
    Extra 'Interesting' Modifier   0  
    Karma-Bonus Modifier   +1  
    Total Score:   3  

  • (Score: 4, Informative) by c0lo on Friday April 12 2019, @03:51AM

    by c0lo (156) Subscriber Badge on Friday April 12 2019, @03:51AM (#828465) Journal

    Friction between trapped air and water will cause the air to start moving inside the 'micro-/nano-cavities' they are trapped in.
    The movement of air will transmit part of that friction to whatever is bound to the ship's wall and defines the cavities.

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford