takingmessages

China used to build your rubber duckies.
Now the they lead research...
Or do they?

https://inews.co.uk/news/scientists-...-flying-424978

Scientists in China target emissions-free flight with air plasma jet engine

The prototype engine uses compressed air and electricity to create enough power to lift a plane in the air

By Madeleine Cuff
May 5, 2020 4:00 pm
Updated May 6, 2020 9:06 amPlanes powered by plasma could usher in a new era of guilt-free flying (Photo: Stuart Franklin/Getty)Scientists have designed a new kind of jet engine that could fly planes halfway around the world without emitting fossil fuels.

The prototype, dreamed up by engineers at Wuhan University in China, relies on thrusters powered by compressed air and electricity to create zero carbon flight.

Green aviation

Flying is one of the fastest-growing sources of greenhouse gas emissions. Researchers have spent years hunting for low-carbon technologies to cut flying’s carbon footprint, but finding a fuel source that is powerful enough to carry a full-sized passenger jet has proved elusive.
“Although electric motors are used in electric cars or small drones to power their motion, they are unpractical to power large aircrafts,” author Dr Jau Tang told i.

Dr Tang and his colleagues believe the answer to low carbon flight lies in something called microwave air plasmas. Their research is published in the journal AIP Advances.

Plasma thrusters

Beyond solid, liquid and gas, plasma is the fourth state of matter. It’s a form of electrically charged gas, which when activated can cause surges of energy.

Plasma jet thrusters have been used before to power NASA probes in outer space, but they were not powerful enough to fuel flight within the earth’s atmosphere.

The team believes it has solved this problem by designing a thruster that creates plasma mid-air, by compressing air into high pressures and using a microwave to charge it. If scaled up, it can create enough thrust to match a commercial jet engine, the scientists claim.

“Unlike fossil fuels, air is free and is clean with no carbon emissions,” Dr Tang said. “Air is present in the atmosphere and there is no need to carry large and heavy fuel tanks as in the conventional airplanes.”
The plasma would be created in the thruster (Photo: JAU TANG AND JUN LI)“Our results demonstrated that such a jet engine based on microwave air plasma can be a potentially viable alternative to the conventional fossil fuel jet engine,” he concluded.
More work is needed to improve the prototype’s efficiency before it can be tried in a full-sized jet, and getting enough electricity to the engine to create plasma could also be a challenge. But if it can work on a large scale, it could usher in an era of guilt-free flying.

tallpilot

Looks good if it didn’t need a nuclear reactor to make enough electricity for it to be viable in anything big enough to be considered a transport.

rickair7777

That's the issue. It may be a more efficient way to USE electricity than motors, power converters, and associated hardware but it's still limited by the specific energy of batteries...

Right now they get to about 250 Wh/Kg on battery packs. Absolute chemical limit for batteries is about 1,000 Wh/Kg (cell level, not pack level) and that's driven by fundamental chemistry and therefore fundamental physics. So don't talk about "breakthroughs" because there won't be any unless you're talking about diluthium crystals and warp drive :rolleyes"

Kerosene has an energy density of about 12,000 Wh/Kg. So best case batteries fall short by over an order of magnitude.

Long term solution for air transport will be low-carbon liquid fuels, basically fuels we manufacture by one means or another by using carbon from the atmosphere (directly or through plant feedstock). Such liquid fuels release the same carbon as jet A but that carbon was previously extracted from the atmosphere, vice being pumped out of deep wells. Green liquid fuels work, and already in very low quantity use by airlines. They just need to scale it up to get costs down. Cost will likely never be as low as petroleum fuels on average, but should be low enough to be economically sustainable.

UAL T38 Phlyer

Spot-on, Rick.

It’s strikingly convenient that their illustration of “RF Power Supply” and “Air Compressor”....require no power source!

Excargodog

That, and repealing the Second Law of Thermodynamics. That too would be helpful...

firefighterplt

Seriously. Neat idea, but not practical, IMO.

You could maybe argue that a ramjet/scramjet could provide the compressed air for this high tech plasma cutter...? Just spitballing.

Hetman

Leakytanks

A potential compromise would be a conventional engine with air driven turbines (big RATs) to supply electrics. The concept would be like ram jet - use conventional to achieve cruise, the air turbines supply power to the plasma engine.

rickair7777

Sounds like a free lunch to me. NSTAAFL.

JamesNoBrakes

Seriously? Have you actually thought this through? Did you pass your systems exam?