[ChrisRowland]

Yep, best we avoid any and all investigation into innovation, really.
It'll only end in tears and the introduction of the Spinning Jenny.

I bet quite a few people lost their fingers in that contraption, until the innovation developed to a point to include interlocked guarding.

If it had been an aircraft all that would have been done was to put a notice up. After that it would be the operator's problem.

[John Bennet]

That actually sparks my imagination on how a plane would fly on hydro power

[T67M]

:scratch: 2MW energy store gives me the mental image a 787 battery...



...but a whole lot worse

A "2MW store" gives me the image of a dimensional instability. Watts measure the rate of energy used. Joules measure the amount of energy stored.

[neilld]

I have to say I am completely baffled by this concept.
For a start, the 2MW generator will require a greater than 2MW gas turbine (due to generator efficiency being less than 100%) in order to drive the 2MW electric motor which will have an electrical input of greater than 2MW (due to the motor efficiency being less than 100%).
The aircraft will have to carry sufficient fuel for the gas turbine.
It is not clear what the energy store of (I assume 2 MWh - not 2MW) will be but if it's batteries then, assuming the current projected best energy density of 0.4 kWh/kg (for LiPo), then the 2MWh store will have a mass of c. 5 tonnes (per engine), this in addition to the mass of fuel required for the above mentioned gas turbine.
Electrical hybrid solutions work in the automotive world where range extender functionality is required but the mission profile in aviation (either GA or commercial) is totally different requiring continuous high power for most of the mission.
I can only assume that the joint resources of Airbus, Siemens and RR have something special up their combined sleeves. (Although committing the schoolboy error of quoting Energy storage in units of Power doesn't inspire much confidence)

[ChrisRowland]

People in the 19th Century were, I believe, reacting in this way to the idea of steam ships. With all the coal that you have to carry there's no capacity for cargo, better stick with sail.

[Straight Level]

(Although committing the schoolboy error of quoting Energy storage in units of Power doesn't inspire much confidence)

One can only assume that the output of the 'energy store' and gas turbine combined is sufficient to power the 4 x 2MW motors for a temporary period during takeoff and climb.
Would the 2MW gas turbine then be sufficient to supply the 4 x "engines" in the cruise? What is the ratio of take off to cruise power of a normal bypass jet engine for comparison.
During descent, excess capacity of the turbine is used to charge the battery store ready for the next take off.
Would regenerative braking effect also charge the battery in a descent i.e 4 x 'engines' are used as generators?

This could work if the total weight of the system is similar to the weight of 4 x conventional bypass engines, but would have noise advantages and I would guess the purchase cost and maintenance overhead of an electric motor being significantly less than a GE or RR turbine???
The batteries would still be a significant cost, but battery technology is advancing very quickly. I can remember, not such a long time ago, when I could only buy zinc carbon batteries for my torch.
SL.

[neilld]

We can only assume that Airbus & co have done their simulations of mission profiles and believe it can be done perhaps along the lines suggested above. I don't know enough about the operating parameters of commercial jets to comment .
However Airbus have form in the field of electric propulsion through the original eFan light aircraft project with many optimistic claims including crossing the channel and even identifying a manufacturing facility only to abandon it, presumably when the penny (or Euro cent) finally dropped.
The recent RAeS GA conference on propulsion contained several thought provoking presentations and would be worth a read once the proceedings are published on their website.

[kanga]

.. (Although committing the schoolboy error of quoting Energy storage in units of Power doesn't inspire much confidence)

Press Release was written for journalists, who cannot be expected to understand that MW is not the same as MWH ..

[skydriller]

.
However Airbus have form in the field of electric propulsion through the original eFan light aircraft project with many optimistic claims including crossing the channel and even identifying a manufacturing facility only to abandon it, presumably when the penny (or Euro cent) finally dropped.

Did they cross the channel? I seem to recall a french homebuilder in a CriCri was the one that did this, Non?
Or was he "just" the first?

Regards, SD..

[neilld]

.. (Although committing the schoolboy error of quoting Energy storage in units of Power doesn't inspire much confidence)

Press Release was written for journalists, who cannot be expected to understand that MW is not the same as MWH ..

Maybe so but wouldn't you expect the likes of Airbus, Siemens & RR to have a vetting process before any technical info was released to the press? After all this will be seen by competitors such as Boeing etc.

[neilld]

.
However Airbus have form in the field of electric propulsion through the original eFan light aircraft project with many optimistic claims including crossing the channel and even identifying a manufacturing facility only to abandon it, presumably when the penny (or Euro cent) finally dropped.

Did they cross the channel? I seem to recall a french homebuilder in a CriCri was the one that did this, Non?
Or was he "just" the first?

Regards, SD..

They did

I think the CriCri may have been first but I seem to recall it was launched piggy back style from a Broussard but not sure. Someone on here will know.

[Paul_Sengupta]

People in the 19th Century were, I believe, reacting in this way to the idea of steam ships. With all the coal that you have to carry there's no capacity for cargo, better stick with sail.

Yeah, but where are the coal powered ships now though? Eh? Eh?

[neilld]

I understand there are ongoing marine projects which utilise sail powered (or assisted) ships.
What goes around comes around.

[kanga]

.. and Mr Trump assured voters in West Virginia that there was a bright future in coal ..

[Dave W]

I think the CriCri may have been first but I seem to recall it was launched piggy back style from a Broussard but not sure. Someone on here will know.

Yes, they scooped Airbus the night before the e-Fan flight and yes, it was a piggyback launch.

Pipistrel were planning to be first, but...

Originally, Pipistrel intended to make the first such Channel crossing using its Alpha Electro two-seat trainer, which is powered by a Siemens 80-hp electric motor. However, at the last minute Siemens demanded that the flight not be made, citing safety concerns. Siemens then banned Pipistrel from any further use of the motor, and asked for its return.