Researchers To Build Underwater Airplane 263
coondoggie writes to tell us that DARPA seems to still be having fun with their funding and continues to aim for the "far out." The latest program, a submersible airplane, seems to have been pulled directly from science fiction. Hopefully this voyage to the bottom of the sea is of the non-permanent variety. "According to DARPA: 'The difficulty with developing such a craft come from the diametrically opposed requirements that exist for an airplane and a submarine. While the primary goal for airplane designers is to try and minimize weight, a submarine must be extremely heavy in order to submerge underwater. In addition, the flow conditions and the systems designed to control a submarine and an airplane are radically different, due to the order of magnitude difference in the densities of air and water.'"
Re:Steve Fossett (Score:5, Informative)
Linky [slashdot.org]
Steve Fossett's Unfinished Project
Posted by kdawson on Sunday October 05, @02:36AM
from the ocean-flying dept.
Transportation Science Technology
MazzThePianoman writes "Steve Fossett left behind a secret vessel project called the Deep Flight Challenger. Fossett was funding the development of a winged submersible being designed by Hawkes Ocean Technologies in California. The intent was for the vehicle to be capable of travel to the very bottom of the ocean -- the Mariana Trench, more than 11,000 meters beneath the surface. 'It would have dramatically, dramatically opened the oceans for exploration. It would have been a game changer,' said Graham Hawkes, the designer. Testing had been completed at Department of Defense facilities. Field testing was only four weeks away when Fossett's untimely death, a year ago, put the project on hold." Hawkes Ocean Technologies owns the design but the vehicle itself is owned by Fossett's estate.
This is Voyage to the Bottom of the Sea (Score:4, Informative)
Re:Steve Fossett (Score:4, Informative)
No, this is an airplane that can also be a submarine (and surface vessel). Fossett was financing a sub that "flew" underwater.
The scifi version would be supercavitating subs (Score:5, Informative)
Supercavitation [wikipedia.org] would allow submarines to move at supersonic (with reference to water) speeds while submerged, and dogfight underwater [space.com] like WWI aircraft did in the air. If they can come to a complete stop they'd be silent and invisible, just floating there, then fire up the engines and go back to moving faster than ship-based sonar would be able to detect them. There's already a supercavitating torpedo [wikipedia.org]. People who design targets -- I mean aircraft carriers and destroyers -- must be worrying about this.
Re:The scifi version would be supercavitating subs (Score:3, Informative)
Although, I think a supercavitating submarine is way cooler, they are basically looking for a seaplane [wikipedia.org] that can sink.
Re:More like "The Incredibles" (Score:3, Informative)
Does Phantom Menace even have a flying submarine? It has a regular submarine...
But anyway, obviously the correct reference is to the submersible squadron from Sky Captain and the World of Tomorrow. Der. Plus: Angelina Jolie!
Utterly Wrong (Score:5, Informative)
I work with ex-submariners. One of the reasons that they hated and feared a real reactor SCRAM was that the sub was essentially relying on its forward motion to maintain it's depth.
Yes, it was negatively buoyant, but the slight upward pitch of its planes enabled it to "fly" through the water. Supposedly, you get much more responsive control that way, rather than wallowing in the water while you wait for tanks to fill or empty. Very important, when you're trailing an aggressive Russian sub...
When the reactor shuts down and the screw stops turning, the damn thing will sink until the control team get the tanks set for neutral or positive buoyancy. Not a comfortable time as the boat heads down and the hull groans and creaks and everyone starts to wonder if there's enough high pressure air in reserve to blow the tanks.
Mainly OT, but by God and by golly, major navies do FLY their subs.
Slashdotters need to get out more (Score:3, Informative)
This type of object exists, we HAVE flying submaringes, they are called BIRDS. Diving birds are NOT constrained by their weight. Their problem is their lungs. Several spieces swim very well under water and can even go straight from flying to submerged.
If birds can do it, so can man.
The trick is to stop thinking of this object as an old fashioned submarine and accept that modern submarines FLY under water. They use their "wings" to control their movement, not their weight.
The biggest challence is re-configuring the wings. Birds can do this easily but swing-wing is out of fashion for a reason. A swing wing that can survive a dive is going to be a major piece of engineering.
Another challenge is getting from one method of propulsion to the other. Birds of course use the same engine and switch effortleslly between legs and wings for power, can humans do the same? Have a single engine that can power motion in air and underwater?
There is however one part of the requirement that might make it more difficult. I think this aircraft is intended for the insertion of seal units quickly without having to worry about air defences. For the seals to disbark from the aircraft underwater it would have to be going very slow or even be motionless. An aircraft that is light and uses negative lift to remain submerged would shoot up like a cork if it stopped.
Key problems:
Power source that can operate underwater.
Two modes of propulsion for air and water.
Switching quickly between modes and both modes not interfering with the other, for instance propellors would probabbly smash during a power dive.
Being able to remain motionless underwater and also submerged.
If it wasn't for the last requirement the trick would be fairly simple, "just" a plane that has positive lift in the air, negative lift under water, super-cavitation speeds to be able to shoot up out of the water with enough speed to remain airborne and a system to switch seamlessly between air and water propulsion.
Do-able. But remaining motionless underwater adds a whole new trick. Suddenly you can use your speed and re-use your wings to remain underwater, you need to alter your weight.
Mind you, I wonder if we at slashdot are not overcomplicating things. What DARPA is looking for is a way to insert seals with minimal detection.
What about an 'ordinary' sea plane that instead of sitting above its floaters can sink beneath them? Imagine an ordinary plane with floaters attacked sticking out the sides and below. It lands on the water as all seaplanes do but then the floaters rotate above the fuselage allowing to disappear beneath the waves. The fuselage opens, allowing sea-water inside removing most of its lift. The floaters act like miniature subs and can submerge to an extent. This aircraft is not about setting records, it has to operate near the coast anyway so can't go to deep in any case.