How to Hide a Submarine

As a submarine moves, it churns the oceans around it, creating an easily detected disturbance. Could a high-tech mesh cloak keep the surrounding waters calm?

Two Duke University scientists are proposing the development of a mesh cloak that could reroute water around submarines to make them harder to detect, New Scientist reports.

When an object moves through fluid, it drags the fluid with it and creates turbulence in its wake. Yaroslav Urzhumov and David Smith say it should be possible to create a mesh cloak that uses a system of tiny pumps and blades to speed up the flow of the fluid around an object so that the fluid is minimally displaced as the object passes through.

In a report in Science Now, Kate McAlpine says that so far, the computer simulation Urzhomov and Smith developed can only demonstrate how the mesh would work for something quite small and moving quite slowly, just a few millimeters per second. McAlpine writes:

Yet even this has applications as the United States military explores the possibilities of automaton spies that look like birds, insects, and fish. Urzhumov proposes that a cloaked robo-minnow could stealthily investigate an enemy submarine, moving slowly but requiring little energy. As for when the first cloaks could hit the water, he speculates that it will take at least 5 years of basic research and development to get a working prototype.

However, he and Smith suggest that a different sort of cloak, made specifically to reduce the drag rather than the entire wake, might be easier to make and could be scaled up to fuel-efficient dream boats.

Image: Wikimedia Commons.