A plane from Britain is met in the US by armed security. The cargo? An experimental engine created by Air Commodore [Frank Whittle], RAF engineer air officer. This engine will be further developed by General Electric under contract to the US government. This is not a Hollywood thriller; it is the story of the jet engine.
The idea of jet power started to get off the ground at the turn of the century. Cornell scholar [Sanford Moss]’ gas turbine thesis led him to work for GE and ultimately for the Army. Soon, aircraft were capable of dropping 2,000 lb. bombs from 15,000 feet to cries of ‘you sank my battleship!’, thus passing [Billy Mitchell]’s famous test.
The World War II-era US Air Force was extremely interested in turbo engines. Beginning in 1941, about 1,000 men were working on a project that only 1/10 were wise to. During this time, American contributions tweaked [Whittle]’s design, improving among other things the impellers and rotor balancing. This was the dawn of radical change in air power.
Six months after the crate arrived and the contracts were signed, GE let ‘er rip in the secret testing chamber. Elsewhere at the Bell Aircraft Corporation, top men had been working concurrently on the Airacomet, which was the first American jet-powered plane ever to take to the skies.
In the name of national defense, GE gave their plans to other manufacturers like Allison to encourage widespread growth. Lockheed’s F-80 Shooting Star, the first operational jet fighter, flew in June 1944 under the power of an Allison J-33 with a remarkable 4,000 pounds of thrust.
GE started a school for future jet engineers and technicians with the primary lesson being the principles of propulsion. The jet engine developed rapidly from this point on.
Continue reading “Retrotechtacular: The Jet Story”
Meet [Alex Spiride]. He’s one of the fifteen finalists of the 2013 Google Science Fair. A native of Plano, Texas, [Alex] entered his squid-inspired underwater propulsion system in the 13-14 year old category.
The red cylinder shown in the image inlay is his test rig. It is covered well on his project site linked above. You just need to click around the different pages using the navigation tiles in the upper right to get the whole picture. The propulsion module uses water sprayed out the nozzle to push the enclosure forward. The hull is made of PVC, with a bladder inside which is connected to the nozzle. The bladder is full of water, but the cavity between it and the hull is full of air. Notice the plastic hose which is used to inject pressurized air, squeezing the bladder to propel the water out the nozzle. Pretty neat huh?
We think [Alex’s] work stands on its own. But we can’t help thinking what the next iteration could look like. We wonder what would happen if you wrapped that bladder in muscle wire? Would it be strong enough to squeeze the bladder?
You can see all fifteen finalists at the GSF announcement page. Just don’t be surprised if you see some of those other projects on our front page in the coming days.
Continue reading “Google Science Fair finalist explains squid-inspired underwater propulsion”
One advantage that skiers have always had over snowboarders is the ability to move through flat sections with ease. [Matt Gardner] built this prototype to help even the playing field. When he would normally need to kick, hop, or remove the board and walk he can now engage his snowboard battery propulsion system.
The rig works much like a paddle boat. The two wheels sticking out to either side of the board push against the slow to move the board forward. The drive train is built from an RC plane speed controller and battery, a motor and gearbox from an 18V drill from Harbor Freight, and a couple of 3D printed gears and mounting brackets. He used a 3D printer to make one drive wheel, then used that to make a silicone mold to cast the wheels used above. The entire assembly is attached to the board with a door hinge. This way the rig can be rotated out of the way (and we assume strapped to his boot) when he’s shredding down the mountain. When paired with an in-goggle HUD this will take snowboarding to the next level!
Unfortunately since it’s already April there’s no snow left to test it on, which means no demo video. But he does tell us that a test run on both grass and carpet went well.