Monday, 6 June 2011

Hot hulls might mean slipperier ships


Want to make a ship move faster through the water? Well, one thing that you can do is paint its hull with low-friction or anti-biofouling paint, to keep barnacles and other marine organisms from growing on it. According to Prof. Derek Chan, from the University of Melbourne's Department of Mathematics and Statistics, another approach that should work is to heat that hull up to a temperature of over 100C (212F). His proposed method is based on a 255 year-old principle known as the Leidenfrost effect.
Named for its discoverer, German doctor Johann Gottlob Leidenfrost, the Leidenfrost effect is the phenomenon wherein a liquid, when exposed to a solid that is significantly above that liquid's boiling point, forms an insulating vapor layer between itself and that solid. This is the reason that water droplets dance across a sufficiently-hot skillet, instead of just evaporating on the spot.
Applying that principle to a ship, Chan believes that a hull kept at an outer temperature significantly above the boiling point of water, should cause a low-friction vapor layer to form between that hull and the water. He tested the theory by analyzing high-speed footage of polished balls being dropped through liquid - their drag was reportedly greatly reduced when they were heated to the point at which the Leidenfrost effect occurred.
Not only could this be used to reduce transportation costs and greenhouse emissions from shipping, he suggests, but it could also be used to speed the flow rate of liquid through pipes.
Chan does, however, admit that keeping the hull so hot could increase the rate of corrosion, and is further researching that possibility. There is also the question of whether the energy required to heat the hull (and keep it hot, as it's exposed to cold ocean water) would be significantly less than the amount of energy that would be saved through the reduction of friction.
The University of Melbourne worked with Saudi Arabia's King Abdulla University on the research, which was recently published in the journal Physical Review Letters.

Related Posts:

  • Some Amazing Mega Structures of the WorldMadeira Airport This fantastic and beautiful international airport is situated close to Funchal, Madeira and has many names as Funchal Airport and Santa Catarina Airport. This airport is standing on pillars as it has ru… Read More
  • Astronomers Suggest Crowdsourcing Letters to Aliens Before trying to contact aliens, maybe we should test the messages on ourselves.In a new paper in the journal Space Policy, three alien hunters suggest designing a standard protocol for writing intelligible letters to extrat… Read More
  • World’s largest container shipI’m sure most people think of container ships as just ships that carry containers and nothing more. Now I don’t know how many of you have actually seen one but these beasts can be quite impressive. And the… Read More
  • The featured stationary paper by Jung Von Matt !!! Featuring zombies on every piece, any interactions with these papers will lead to the beheading or puncturing of these undead characters. Perfect for a Halloween greeting, these stationary pieces by Jung Von Matt will keep … Read More
  • Nasa's plans five more missions on moon With two currently functioning orbiters, and five more missions planned in the next year, Earth's Moon may soon have seven active probes operated by five nations, with even more coming soon. NASA's plans to return humans to … Read More

0 comments:

Post a Comment