easyJet unveils plans for hybrid aeroplanes

[captain cactus]

Source:http://www.discovery.com/dscovrd/tech/european-airline-unveils-plans-for-hybrid-jetliner/

 

 

Quote

 

An innovative fuel cell system could save British airline easyJet more than 55,000 tons of fuel each year, significantly cutting down the company's carbon footprint.

Earlier this week, the low-cost carrier unveiled its hybrid plane concept, which harnesses energy produced by the aircraft's braking system. Stored in lightweight hydrogen fuel cells, that energy is then used in place of the plane's jet engines during taxiing, which accounts for approximately 4% of the airline's fuel consumption.

 

 

 

So I suppose you have electric motors in the wheels connected to the fuel cells which provide the electricity needed so you can taxi around with them, and then disconnect the motors while taking off/landing. And the reason we haven't thought of that earlier is...

 

You basically have that Toyota Mirai hydrogen car but in airplane form. It looks way better too. The plane, that is.

[babadoctor]

yes

airplanes will be cheaper now to fly?

[Prysin]

making lightweight motors with extreme torque to push a airplane is damn hard. That is why this hasnt happened before.

 

not to mention the forces said motor must endure at touch-down. 300+ tonns of airplane hitting the ground at 250-300KM/H and having to reduce said speed to less then 20KM/H within 2000m of airstrip.

 

You can use hydraulic couplings to disconnect the motor and wheel hub, but that comes at the cost of weight and in the airline industry, every single KG matters to overall fuel efficiency.

[Dabombinable]

3 minutes ago, Prysin said:

making lightweight motors with extreme torque to push a airplane is damn hard. That is why this hasnt happened before.

 

not to mention the forces said motor must endure at touch-down. 300+ tonns of airplane hitting the ground at 250-300KM/H and having to reduce said speed to less then 20KM/H within 2000m of airstrip

All i can say is, if the Concorde's flaws had been fixed from the start, what they are attempting would have been even more difficult due to its take off and landing speeds. I could only see it working in small planes with low take off and landing speeds.

[Prysin]

1 minute ago, Dabombinable said:

All i can say is, if the Concorde's flaws had been fixed from the start, what they are attempting would have been even more difficult due to its take off and landing speeds. I could only see it working in small planes with low take off and landing speeds.

again, you CAN use hydraulic couplings to do this. But this adds weight as the coupling must be VERY robust.

By forcing hydraulic fluid between two plates, you can disconnect the motor from the actual wheel hub assembly. Thus the only force on the motor would be the rotational force of the hydraulic fluid. Which under no circumstance should overcome the inertia of a large electric motor.

[Dabombinable]

25 minutes ago, Prysin said:

again, you CAN use hydraulic couplings to do this. But this adds weight as the coupling must be VERY robust.

By forcing hydraulic fluid between two plates, you can disconnect the motor from the actual wheel hub assembly. Thus the only force on the motor would be the rotational force of the hydraulic fluid. Which under no circumstance should overcome the inertia of a large electric motor.

Working as in actually saving fuel while the system maintains reliability without the need for longer run ways. And thinking on it some more, what about a hydraulic motor with an electric pump?

[Prysin]

Just now, Dabombinable said:

Working as in actually saving fuel while the system maintains reliability without the need for longer run ways. And thinking on it some more, what about a hydraulic motor?

hydraulic engines are much heavier then electric. As they need to be machined with solid steel or aluminium channels with a impeller of various design inside. However this is incredibly heavy. And it would require the hydraulic pump inside the plane to be increased in capacity. There is also the issue of pipes. Every bendable pipe is a potential failure point. Condensation inside the lines could cause blockages. The wheel-wells are also not heated, so if it is -50C outside the plane at 30,000FT, which it is, then it is around -30 to -40 inside the wheel-well. However the decent to hotter parts of the atmosphere is rather quick, not to mention the hydraulic fluid itself becomes increadibly hot very fast once put to work. meaning material fatigue is a real danger due to repeated cycling of heating and cooling.

 

Then there is speed. Planes must be able to tax at around 20-50KPH, going slower will heavily impact airport schedules as taxi queues will wastly increase. Therefore, being able to taxi at the highest, safe, speed as possible is vital. In order to make a fast AND strong hydraulic motor, the hydraulic system in the plane, especially the pump, would need a capacity upgrade.

Either way, the issue with a hydraulic coupling, is the same as the motor. Redundancy.

You need extra hoses/pipes, killswitch and rerouting valves for every "motorized" wheel. Because if you do not, the whole plane could "bleed to death" if a hose ruptures.

Incase you didnt know, ALL the planes rudders are hydraulicly operated with three main "pipes" running to the back and to each wing. With a smaller assembly going to the landing gear. Although the landing gear CAN be "dropped" into place if emergency dictates it.

[Extrememining]

I have flown on easy jet. It is shit. They don't have screen! Let me repeat that THEY DON'T HAVE TV SCREENS!

[Dabombinable]

1 minute ago, Prysin said:

hydraulic engines are much heavier then electric. As they need to be machined with solid steel or aluminium channels with a impeller of various design inside. However this is incredibly heavy. And it would require the hydraulic pump inside the plane to be increased in capacity. There is also the issue of pipes. Every bendable pipe is a potential failure point. Condensation inside the lines could cause blockages. The wheel-wells are also not heated, so if it is -50C outside the plane at 30,000FT, which it is, then it is around -30 to -40 inside the wheel-well. However the decent to hotter parts of the atmosphere is rather quick, not to mention the hydraulic fluid itself becomes increadibly hot very fast once put to work. meaning material fatigue is a real danger due to repeated cycling of heating and cooling.

 

Then there is speed. Planes must be able to tax at around 20-50KPH, going slower will heavily impact airport schedules as taxi queues will wastly increase. Therefore, being able to taxi at the highest, safe, speed as possible is vital. In order to make a fast AND strong hydraulic motor, the hydraulic system in the plane, especially the pump, would need a capacity upgrade.

Either way, the issue with a hydraulic coupling, is the same as the motor. Redundancy.

You need extra hoses/pipes, killswitch and rerouting valves for every "motorized" wheel. Because if you do not, the whole plane could "bleed to death" if a hose ruptures.

Incase you didnt know, ALL the planes rudders are hydraulicly operated with three main "pipes" running to the back and to each wing. With a smaller assembly going to the landing gear. Although the landing gear CAN be "dropped" into place if emergency dictates it.

I know about the hydraulics already in use, but the main system could not be used to power multiple hydraulic motors without a serious re-design. I suppose another thing that could be used is some mechanism to disengage whichever motor is used completely from the wheel's. Though when the plane is landing the gears would need to be aligned correctly so it might not work.

[Prysin]

40 minutes ago, Extrememining said:

I have flown on easy jet. It is shit. They don't have screen! Let me repeat that THEY DON'T HAVE TV SCREENS!

who cares, its only shit on airplane TVs anyway. except KLM on trans-atlantic flights

 

[suicidalfranco]

1 hour ago, babadoctor said:

yes

airplanes will be cheaper now to fly?

nope, price stays the same, profit increases NUAHAHAHA

[SansVarnic]

The idea is intriguing but the practical and realistic application is flawed.

[Carde]

3 hours ago, Extrememining said:

I have flown on easy jet. It is shit. They don't have screen! Let me repeat that THEY DON'T HAVE TV SCREENS!

They are cheap and reliable and don't save money is stupid and perhaps dangerous ways like certain other budget carriers (Ryanair anyone?)

 

Beside all flights within Europe barely anything has screens and frankly does anyone still use those today? I put stuff on my phone, laptop or dig out the old tablet or heck even read a book before caring about IFE on short trips.

 

Back to the tech outside of the difficulty implementing such a system it is also weight, weight which has to be lugged around which costs fuel, which in turn reduces the savings and frankly with oil prices as they are airlines don't care about fuel savings that much anymore. This is clearly seen in how older designs sold at lower prices due discounts (737, A320 families) outsell new highly efficient planes like the Bombardier CS series which more expensive to buy on front, but burns a lot less fuel. However no airline really is all that bothered.

 

So nice idea, but I doubt it will happen within the next decade and I think before it will happen even after that we will figure out a better way to taxi planes which does not add extra weight

[demonix00]

On 06/02/2016 at 0:25 AM, Carde said:

They are cheap and reliable and don't save money is stupid and perhaps dangerous ways like certain other budget carriers (Ryanair anyone?)

Aren't Ryanair the ones that charge a low price for the flight, but forget to mention that there are a lot of extra charges to pay (and the boss did consider charging a pound so that passengers could spend a penny).

[Carde]

18 hours ago, demonix00 said:

Aren't Ryanair the ones that charge a low price for the flight, but forget to mention that there are a lot of extra charges to pay (and the boss did consider charging a pound so that passengers could spend a penny).

Likely, they are also the company that forbids it's employees from charging their mobiles at work because it saves them 40 pounds a year. They are also a company where a lot of smoke keeps rising from pilots and other staff regarding fuel policies (aka cutting it short) and well we can go on forever

 

But I will let it die, to much of topic.

[Watermelon Guy]

On 2/5/2016 at 7:47 PM, lots of unexplainable lag said:

 

Please change "Airplane" To "Aeroplane". It is plane of the air, not plane air.

[Tataffe]

Easyjet is an airline, not an airplane manufacturer. They do not build airplanes. All they do at max is publish a wish they have.

 

Speaking as an aerospace engineering student, there are plans to move more of the airplane's system away from hydraulic towards electric, a trend called "more electric aircraft" (MEA) or "all electric aircraft" (AEA). The Boeing 787 (also called the "Dreamliner" or "seven-late-seven") is a MEA, for instance. These planes need way larger batteries and more powerful electric generators in their engines than conventional planes.

 

There are plans to put electric motors to the undercarriage wheels in order to do the taxiing with electric energy provided by the batteries or the auxiliary power unit (APU), because jet engines are horribly inefficient in near-idle-mode (like during taxi). This makes sense especially on short- to middle-range airliners, where taxiing is a comparably large part of the flight cycle. Also these electric motors could help to accelerate the aircraft during takeoff, severely reducing takeoff distance.

 

Further information can be found in this research paper: http://www.dglr.de/publikationen/2013/301445.pdf

[Mihle]

On 5.2.2016 at 9:43 PM, Extrememining said:

I have flown on easy jet. It is shit. They don't have screen! Let me repeat that THEY DON'T HAVE TV SCREENS!

I dont care, because the company I use the most when flying (Norwegian (Air Shuttle)) they have a system where you connect your whone to their wifi, and you can watch some movies and series for free, and some for a cost. and you can use the web(isnt very fast tho) you can also watch live TV if those few channels have something I will watch when I am on the plane. You can aslo get more info on where you are on the map, speed, how far left and stuff. on your phone. the only thing you need to do is to connect to their wifi.

 

So the only screen I need on the plane, is the one I have in my pocket. (can use a Laptop too if you wich)