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The US Navy and NASA’s Jet Propulsion Laboratory are developing a engine that can efficiently generate energy from heat in the water. This engine could propel a ship indefinitely:
SOLO-TREC is outfitted with a series of tubes full of waxy phase-change materials. As the float encounters warm temperatures near the ocean’s surface, the materials expand; when it dives and the waters grow cooler, the materials contract. The expansion and contraction pressurizes oil, which drives a hydraulic motor. The motor generates electricity and recharges the batteries, which power a pump. The pump can change the float’s buoyancy, allowing it to move up and down the water column.
“In theory what you have now is unlimited endurance for something that has this type of engine,” said Thomas Swean Jr., team leader for ocean engineering and marine systems at the Office of Naval Research, which funded the project. “Other things can break, but as far as the energy source, it will only stop working if the ocean ran out of energy, which is unlikely to happen … One of the Navy’s goals is to have a persistent presence in the world’s oceans. This is the type of technology that leads you to that.”
Link | Photo: NASA/JPL/U.S. Navy/Scripps Institution of Oceanography
With a flight lasting twenty-six hours and one minute, the US Navy experimental unmanned aerial vehicle Ion Tiger broke a flight endurance record. Michael Barkoviak writes for Daily Tech:
The U.S. Navy’s Ion Tiger flew over the Aberdeen Proving Ground on November 16 and November 17 for more than one day, as the 37-lb. aircraft carried its fuel-cell engine, 9.5-lb. compressed hydrogen tank, and a five-pound payload.
Ion Tiger has a a day-night camera capable of surveillance and reconnaissance for future missions, said representatives from the Naval Research Laboratory. The recent test flight was meant as an endurance test, and researchers were quick to point out that much work is left to be done.
Link via CrunchGear | Image: Naval Research Laboratory
Navy chemists claim to have refined short chain hydrocarbons from seawater and hope to develop kerosene-based jet fuel from the process:
The process involves extracting carbon dioxide dissolved in the water and combining it with hydrogen – obtained by splitting water molecules using electricity – to make a hydrocarbon fuel…
Dorner and colleagues found that using the usual cobalt-based catalyst on seawater-derived CO2 produced almost entirely methane gas. Switching to an iron catalyst resulted in only 30 per cent methane being produced, with the remainder short-chain hydrocarbons that could be refined into jet fuel.
These drones include both aerial and surface craft intended for clandestine operations:
* Sea Stalker, a torpedo-size underwater robot that specializes in snooping on radio signals and other communications. “The [concept] is to launch these from submarines at night,” Kenny said. “They will transit to offshore, anchor, put their antennas out and begin collection. Ideally you would have a series of these … to cover different ports or hotbeds of terrorist activity. And then you would collate that information on board the ship.”
* Scan Eagle, the 45-pound aerial bot that has seen heavy use by the Marines in Iraq and Afghanistan. Kenny says Special Operations Command is looking at boosting Scan Eagle with extra fuel and sensors — and maybe even weapons, like the Air Force’s armed Predators and Reapers. It seems Scan Eagle is launched from a sub’s deck while she is surfaced, but that could change. “We’re looking at launch and recovery from an SSGN payload tube to allow clandestine close-in operations,” Kenny said.
* BUSTER, a 15-pound UAV that Kenny says is particularly useful when working with foreign armies. “We’ve … done some very successful operations with allies, doing foreign internal defense, training them to operate this vehicle.” The allied armies launch BUSTER from land, while the submarine “pull[s] in the full motion video and the infrared, correlate[s] it and fuse[s] it in our battle management centers on board.”
The picture above is of the Sea Stalker. [Correction on 8.3.09: It's the Sea Stalker by General Dynamics and is unmanned, but is a surface, rather than subsurface craft. Thanks, AeroNut!]
Previously on Neatorama: The Navy’s Armed Sea-Bots
The fastest submarine in the US Navy can go only 25 to 30 knots. But the Electric Boat Corporation, the primary designer for US Navy submarines, is trying to design one that can reach up to 100 knots. It plans on testing a 1/4 scale model off the coast of Rhode Island next year:
The sub utilizes the phenomenon known as supercavitation. Supercavitation is the process wherein an object moves so fast through the water that it creates a gas bubble around itself, nearly eliminating drag. Unencumbered by the high drag of water, the object is free to speed along at much higher speeds than otherwise possible. Supercavitation has been known since the end of World War Two, and the Soviets succeeded in creating a torpedo that utilizes supercavitation for high-speed travel, but so far no one has succeeded in scaling the effect up to the size of a whole submarine.
