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A team of engineers has created plasma engines that work at ground level, with the hope of eventually enabling plasma propulsion for airplanes:
Plasma engines have been stuck in the lab for the past decade or so. And research on them has largely been limited to the idea of propelling satellites once in space.
[...] Plasma jet engines tend to be designed to work in a vacuum or the low pressures found high in the atmosphere, where they would need to carry a gas supply. But now Göksel's team has tested one that can operate on air at a pressure of one atmosphere (Journal of Physics Conference Series, doi.org/b66g). "We are the first to produce fast and powerful plasma jets at ground level," says Göksel. "These jets of plasma can reach speeds of up to 20 kilometres a second."
[...] But there are several hurdles to overcome before the technology can propel an actual plane. For a start, the team tested mini thrusters 80 millimetres long, and a commercial airliner would need some 10,000 of them to fly, which makes the current design too complex for aircraft of that size. Göksel's team plans to target smaller planes and airships for now. Between 100 and 1000 thrusters would be enough for a small plane, which the team thinks is feasible.
[...] Göksel is hoping for a breakthrough in compact fusion reactors to power his system. Other possible options could be solar panels or beaming power wirelessly to the engines, he says.
Similar concepts: VASIMR and SABRE.
(Score: 2) by JoeMerchant on Monday May 22 2017, @02:33PM (1 child)
It's basically the next step past turbo-jet engines. Turbines aren't terribly efficient when compared to internal combustion, but there's only so fast that a piston (or Wankel or...) engine can spin a shaft.
I looked at the idea (similar to the https://en.wikipedia.org/wiki/Jaguar_C-X75 [wikipedia.org] ) of a turbine driven generator for electric vehicle... you can get "surplus" APU turbines fairly cheap, but you can't afford to feed them. It would work, it would work well, but initial fuel economy would be sub 10-mpg. Jaguar made million euro+ prototypes with more refined micro turbines, and they did claim less than 99g/km CO2 emissions (less than half of a "typical car" https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle-0 [epa.gov] ), but who knows what kind of spec-puffery was involved to get that number?
So, what's the turbine really good at? Going fast. What's the plasma engine really good at? Going faster.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Monday May 22 2017, @07:18PM
You can make a fuel-efficient turbine. The problem is that it will be absurdly expensive. You'll need to 3D-print the blades in wax, then use a lost-wax process to cast single-crystal superalloy metal. Normally you'd only bother for commercial jets.
The other issue is NO2 emmissions. Bragging about CO2 is a distraction from NO2. The more efficient the engine, the higher the pressure and temperature must be, and that creates NO2.