Submersible Glider Powered By Thermal Changes

An anonymous reader writes about a new robot submersible that uses temperature differences in the sea to power operation for more than twice as long as previous, battery-dependent vehicles. "The torpedo-shaped glider moves through the ocean by changing its buoyancy to dive and surface, unlike motorized, propeller-driven undersea vehicles. To power its propulsion, the submersible gathers thermal energy from the ocean. When it moves from cooler water to warmer areas, internal tubes of wax are heated up and expand, pushing out the gas in surrounding tanks and increasing its pressure. The compressed gas stores potential energy, like a squeezed spring, that can be used to power the vehicle. To rise, oil is pushed from inside the vehicle to external bladders, thus increasing the glider's volume without changing its mass, making it less dense. The oil can be shifted inside to increase the density and sink the vehicle."

Re:Sounds like the perfect drug-smuggling device.

[MichaelSmith]

I can't see it working well in shallow waters. I don't think it would have much scope for navigation either, as it spends most of its time at depth away from GPS signals.

For a drug mule you want something you can deploy and collect at a precise location on a beach, which for me, means a solar powered UAV which will sit just below the surface. Not that I have tried to build any such thing of course.

Human drug mules are cheaper anyway.

Vaporware tag seems unjustifed

[sapphire wyvern]

Built by the Webb Research Corporation in Falmouth, Mass., the new submersible has successfully traveled back and forth between two of the U.S. Virgin Islands, St. Thomas and St. Croix, more than 20 times. WHOI researchers plan to use the data gathered by the craft to study ocean currents in the area.

Since when is something that physically exists and has been tested in the field vaporware?

Re:Wait... what?

[don depresor]

and newer subs are not motorized, but nuclear-powered. Excuse me but what do you think a nuclear reactor and a turbine are? If they had 100 guys pulling a lever that moved the propeller, then you could say that they aren't motorized ( and you could argue that they have an human motor anyway...). But saying that a nuclear sub isn't motorized...

Irritating first line of article though

[Kupfernigk]

"Scientists have invented the Prius of ocean-going submersibles - a new "green" robotic glider that runs on energy absorbed from the heat of the sea, rather than batteries."

Scientists research, they discover, they do not invent. Engineers invent. Doesn't anybody in journalism know the difference between a scientist and an engineer? Also, the Prius is actually a bit like a conventional submarine - IC engine charges the batteries - and is therefore (from a marine engineering perspective) very old tech dating from before WW2. This on the other hand is seriously clever. In fact, it's like powering your car off a massive array of engine thermostats (which rely on wax as the operating means.) So a better lead in would be "Engineers have developed an energy efficient vehicle which is nothing whatever like a Prius - it uses temperature gradients in the sea to power itself."

Perhaps Microsoft deserves to take over Yahoo.

Re:Sounds like the perfect drug-smuggling device.

[don depresor]

You know that nuclear subs have been traveling underwater for years before the existence of GPS tech, right?

You have things like inertial systems, the old magnetic compass, sonars that help you by telling you the features of the sea bottom (you know like the old age when you looked for a landmark you knew and used it to locate yourself) and other things...

Re:Wait... what?

[Simon Brooke]

"The torpedo-shaped glider moves through the ocean by changing its buoyancy to dive and surface, unlike motorized, propeller-driven undersea vehicles"

Last I checked submarines had air tanks for buoyancy control, and newer subs are not motorized, but nuclear-powered. Something change in the past few hours while I was sleeping?

And those 'newer subs' use a nuclear reactor to power - guess what? - a motor.

There was a time when the average slashdot user had more than two braincells to rub together, but that time seems sadly past.

Re:A reality check on this

[chuckymonkey]

They never said that it had to carry people, and I bet it's a great research vessel since they have one working as a previous poster already said. Since it rides thermal currents in the ocean I think that you could put a GPS tracker in it and find some very good data about changing ocean currents, not to mention the vast amounts of other data you could gather with something like this that doesn't really need to refuel or resupply.

Re:Irritating first line of article though

[xPsi]

Scientists research, they discover, they do not invent. Engineers invent. Doesn't anybody in journalism know the difference between a scientist and an engineer?

I'm guessing since you just invented that distinction you are an engineer then? Seriously, I know plenty of scientists and engineers who do a healthy mix of research, discovery, and invention. Science journalism may have other problems, but I don't think this is one of them.