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Siemens and Airbus To Push Electric Aviation Engines (networkworld.com)
coondoggie quotes a report from Networkworld: Siemens and Airbus teamed up today to develop electric and hybrid electric/combustion engines for commercial and private aircraft. The companies said they would amass a joint development team of about 200 employees that would jointly develop prototypes for various propulsion systems with power classes ranging from a few 100 kilowatts up to 10 and more megawatts, for short, local trips with aircraft below 100 seats, helicopters or unmanned aircraft up to classic short and medium-range flights. Hybrid-electric propulsion systems can significantly reduce fuel consumption of aircraft and reduce noise. European emissions targets aim for a 75% reduction of CO2 emissions by 2050. These ambitious goals cannot be achieved by conventional technologies, the companies stated. Airbus has developed a 2-seat electrically powered aircraft, known as the E-Fan. Siemens too has been developing an electric aircraft engine.
I would imagine not. On the other hand, there are other ways of storing energy than batteries (like hydrogen fuel cells).
Get the electric airplane engine working. Let someone else worry about storing the electricity to power it.
If they will reduce CO2 output, it will come at significant cost, significant expense.
Significant expense for consumer is, at the same time, significant revenue to the counter party. Extracting revenues is the main point of all the initiatives.
I'm sure this is all new information to them.
"Old man yells at systemd"
There has not been the R&D to make those "safer modern designs" into physical objects and ensure that a prototype works as designed and can be altered to produce something good enough to go into production.
Software models don't quite match up to reality in a lot of areas guys. The real world has turbulent flow and other stuff that doesn't model well.
Due to traction limitations of steel-on-steel, locomotives are heavy by design and the diesel-electric weight is not a disadvantage. The same does not apply to airplanes.
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The engine is the easy part. We already have plenty options for efficient electric engines on any power range you'd like. I recall a group called "Bye Electric" fitting a C172 with a 200hp electric engine with little issues.
Power storage is everything. Every single option to store electric energy onboard an aircraft is orders of magniture less power-density efficient than gas.
It has a much poorer energy density by weight and volume than jet fuel.
Volume yes, weight no. There's a reason why hydrogen was used in the first stage of the Saturn V.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Wow, all the comments on this article have completely missed the point of this. IDIOTS are not pushing this - the concept offers very real efficiency improvements.
The primary constraint in modern jet aircraft efficiency is the propulsive efficiency - turning the mechanical shaft power into forward thrust. This is fundamentally limited by the size of your fan for a given airspeed. If you make the fan swept area a little bit bigger, you can get major improvements in the overall efficiency of the aircraft. This is why newer airplanes always have bigger and bigger engines (787 vs 767, 737NG, A320NEO).
However there are limits to how big you can go. One problem is physically fitting a large diameter engine into existing airframe designs. On the 737NG they had to raise the nose landing gear to accommodate the new engines. There are practical limits to how much you can keep doing this sort of thing without having to create a completely new airframe (the 737 is a 1960s airframe). The other problem with larger fan blades is that the tip speed increases with diameter, which means the fan RPM must reduce to prevent supersonic airflow. This then creates a compromise on the turbine section of the engine. The newest generation of engines are now using gearboxes so that the turbine can run at a higher speed than the fan, which lets them go to larger bypass ratios. The cost, however, is in weight and complexity.
The big benefit that hybrid electric could offer is being able to effectively increase the fan area by distributing fans along the wing. This could create massive efficiency gains, and bring jet aircraft closer to the efficiency of turboprops. Imagine a 737 with two large electric fans next to each other. This could double the swept area on the same fuselage. Further, the concpept could make boundary layer ingestion designs practical, and these also offer big advantages in terms of efficiency for future airframe designs.
This is not about making battery powered aircraft. It is about re-arrangement of the aircraft systems to provide better propulsive efficiency.
Hydrogen eats steel and aluminum.
I noticed there is a strong groupthink on Slashdot that is against hydrogen fuel cell technology. And one of the (blatantly incorrect) statements is that hydrogen is impossible to store. And yet, there are multiple car manufacturers that make viable hydrogen-powered cars, and the hydrogen storage is not the problem at all. The problem is the current common methods of producing hydrogen, and the (non) availability of gas stations.
I swear that the collective Slashdot IQ falls through the floor when fuel cells, especially hydrogen fuel cells, are the topic. The dumbest, least researched statements, get the most upvotes. It's embarrassing to watch.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
I assumed they meant to say "wasn't" ;)
Indeed, to sum up:
Mass density: excellent
Volumetric density: horrible
Thrust: poor (though probably not an issue for passenger jets)
Ease of ignition: easy. Burns aggressively in almost any fuel-air mixture, requires only a trivial spark to ignite, and burns can accelerate from deflagrations to detonations in many circumstances.
Ease of accidental ignition: likewise, easy.
Liquid storage: very difficult. High boiloff rate (liquefies air outside its tank), lots of energy goes into creation (incl. ortho/para conversion), entrained air freezes out as a highly explosive ice, subpar compatibility with composites, metal embrittlement over long periods. Boiloff gases pool under overhangs / enters pipes & follow them to their destinations.
Gas storage: difficult. Requires very high pressures for even low densities; high leakage rate and metal embrittlement over long periods. Leaked gas pools under overhangs / enters pipes & follows them to their destinations.
Airflow required for stoichiometric burn: high (~17kg air per kg kerosene, ~40kg air per kg H2)
Basically: as a fuel, hydrogen is both wonderful and terrible.
If I ever become wealthy and mad, I'll leave Companion Cubes on desert islands for shipwreck survivors.