Monday, November 3, 2014

Tiny bubbles and big ships...

Tiny bubbles and big ships...  Mitsubishi Heavy Industries is building giant ships that travel through the seas more efficiently by squirting tiny air bubbles to “lubricate” the interface between the water and the hull.  They claim efficiency improvements of 25% – saving far more energy than it takes to compress air for the bubbles.

This is what happens when you challenge engineers with tough problems: they come up with answers, and not necessarily what you'd expect.  This team was challenged to make ships more efficient.  They didn't take any of the obvious traditional approaches (change the hull shape, change the propulsion system, etc.).  I'd love to know what piece of insight led to the idea of making the ship ride on a blanket of compressed air bubbles!


  1. Wasn't this the idea behind super cavitating torpedoes? I think it is also somewhat the idea why shark skin is rough rather than smooth letting them go faster through the water.

  2. From what I've read about those super-cavitating torpedoes, they're actually "flying" inside a single big bubble, completely avoiding all the friction with water. I don't know if that's the same mechanism as the sheet of little bubbles, but surely it's related. Don't know a darned thing about shark skin, but I have read a theory that the "give" in the rubbery skin of a porpoise or whale reduces the friction they have in the water...