[Cad] [motors, power ee, & evs] (Siemens) Electric aircraft: World-record (50kg:260 kW contiunuous) electric motor makes first flight. also, electric dirigibles from 1885?!

Tue Jul 12 08:05:22 EDT 2016

Regardless of motor advances, batteries will still be primary issue due to
the mass fraction they need to take up. Even with a major improvement in
aero (co-flow airfoil
<http://www6.miami.edu/acfdlab/publications/AIAA-2015-0772.pdf>, or BLI
<http://web.mit.edu/drela/Public/N+3/Uranga2014_compressed.pdf>), the L/D
is still nowhere near what it needs to be for airliners, which are majority
of aviation emissions. This is where the whole Musk electric jet
<https://en.wikipedia.org/wiki/Musk_electric_jet> thing gets very dodgy, or
just beyond what we think is possible atm. To go cross country at 600
Wh/kg, you need a L/D of 30, for something that is *supersonic. *Play
around with the numbers <http://web.mit.edu/lochie/www/erange/main.html>,
and you'll hopefully see what I mean.

There's very little way of getting around the fact that batteries are
approximately 100x heavier than kerosene on energy basis.

On Tue, 12 Jul 2016 at 18:46 Nancy Ouyang <nancy.ouyang at gmail.com> wrote:

> sweet pdf, though lol loweffort response :p yes ofc batteries
>
> I believe the PDF is 2012 (why oh why don't people put date writtens or at
> least year written in their documents)
>
> The few electric motors available toda*y for aircraft propulsion *have a
>> power output of *less than 100 kW*. Large electric motors are also used
>> in trains, ships and submarines, but here the mass is less important. Today
>> it seems to be possible to build electric motors having a *specific mass
>> of about 2 to 4 kW/kg*. This compares favorably with the specific mass
>> of larger turboshaft and turbofan engines at cruise power (see Figure 13
>> and Figure 14). *Future developments* may extend the range of electric
>> motors to values of *up to 8 kW/kg*, but there is a strong need for the
>> development of lightweight electric motors, specifically designed for
>> application in aircraft.
>>
>
> so this gives context to why siemen's motor is cool.
>
> 260 kW / 50 kg =* 5.2 @ 260 kW* or roughly *orange* circle:
>
> [image: Inline image 1]
> pg 12
>
> *does anyone know what the comparable previous weight would be before this
> motor? *this one is 50kg &  if this is a lot less than before, it's just
> another notch in reducing weight to make weightspace for battery packs
> perhaps.
>
>
> Range sensitivities Equation 11 shows that in order to achieve maximum
>> range for a given aircraft mass A lightweight aircraft is more sensible to
>> a change in mass than a heavy aircraft.
>
>
> I love their *"let's think through how we'd make this work" thought
> experiment* section:
>
> Applying this simulation model to a specific aircraft allows determining
>> the possible performance and the technology improvements required to
>> achieve the desired results
>
>
> The range of the original aircraft with 32 passengers is about 1200 km.
>> With a reduced payload of 28 passengers the maximum range is approximately
>> 2200 km
>
>
> Using current (2012) technology this aircraft would reach a range of 202
>> km. The flight time would be about 40 minutes. Cruise speed would be about
>> 300 km/h. If an additional reserve of 30 minutes for holding at the
>> destination airport would have to be considered, the practical range would
>> drop to 50 km.
>
>
> The next modification would reduce the empty mass of the aircraft by 20%.
>> This would require introducing extreme lightweight design features
>
>
> This step improves the battery technology by doubling the mass specific
>> energy * E . *Such an improvement is quite well possible with future
>> development of Li-S battery systems within the next 15 years*. This
>> modification would double the range to 711 km so that it at least comes
>> into the order of the kerosene based aircraft. Nevertheless, there is still
>> a factor of 3 in range missing. In order to achieve the range of the
>> original aircraft, the battery technology would have to be improved by this
>> factor, i.e. a factor of 6 compared to todays (2012) technology.
>
>
> Furthermore new infrastructure to replace and recharge the batteries on
>> each airport would be required to make such an aircraft feasible
>
>
> Comparing the payload-range characteristics of the baseline turboprop
>> aircraft and the battery powered electric aircraft shows that trading
>> payload for fuel respectively battery has a very beneficial effect in case
>> of kerosene because of its high specific energy
>
>
>> If, on the other hand, the final extremely modified aircraft 328-LBME2
>> would be equipped with a current turbo-prop engine, its fuel consumption
>> would be as low as 1.5 liters per passenger per 100 km, which is about half
>> that of the baseline aircraft.
>
>
>
> (This last stat is mostly due to how light and dragless the author's
> thought-experiment is, I think.)
>
> Thanks,
> --Nancy
>
> ~~~
> my personal blog <http://www.orangenarwhals.com>, orangenarwhals
>
> On Tue, Jul 12, 2016 at 2:48 AM, Lochie Ferrier <lochieferrier at gmail.com>
> wrote:
>
>> The batteries though. The batteries are what makes it super hard
>> <http://www.mh-aerotools.de/company/paper_14/MP-AVT-209-09.pdf>.
>>
>> On Tue, 12 Jul 2016 at 16:31 Nancy Ouyang <nancy.ouyang at gmail.com> wrote:
>>
>>> www.siemens.com/press/electric-aircraft
>>>
>>> *"This is the first time that an electric aircraft in
>>>> the quarter-megawatt performance class has flown."*
>>>
>>>
>>> https://www.youtube.com/watch?v=fiu8TFnXYFY
>>>
>>> In a big leap for the electrification of aviation, an Extra Aircraft
>>>> aerobatic plane performed its maiden flight with an electric powertrain.
>>>> The crucial component was a world record motor from Siemens. Weighing a
>>>> mere 50 kilograms, the motor has an output of 260 kilowatts, resulting in
>>>> an unparalleled power-to-weight ratio.
>>>
>>>
>>> Datasheet:
>>> http://www.siemens.com/press/pool/de/feature/2015/corporate/2015-03-electromotor/factsheet-erstflug-weltrekordmotor-d.pdf
>>>
>>>
>>>
>>> https://transportevolved.com/2016/07/08/siemens-showcases-brand-new-electric-motor-thats-super-light-super-powerful-and-perfect-for-electric-airplanes/
>>>
>>>> Of course, electric motors have long been used in model planes, but
>>>> their use outside the 1:14th scale aeromodelling arena has been
>>>> somewhat limited due to the mechanics of making a sufficiently large,
>>>> powerful, & lightweight electric motor. And while we’ve seen some very
>>>> successful electric planes take to the sky, most have been custom-made,
>>>> super-lightweight affairs which while impressive, have yet to make their
>>>> mark on a wider scale.
>>>
>>>
>>> Many of the benefits of electric motive power for aircraft are ones that
>>>> any EV driver will be familiar with: quieter, lower maintenance, greater
>>>> efficiency. Benefits that are shared with the community too in this case –
>>>> as with increasing air travel areas around airports have become
>>>> increasingly polluted – both by noise and by noxious residues from burning
>>>> fossil fuels.
>>>>
>>>
>>>
>>>> But there are also other benefits that are deeply exciting for
>>>> aeronautical engineers and pilots.
>>>
>>>
>>>
>>>
>>>> Unlike fossil fuel powered engines, electric motors really don’t care
>>>> which way is up. They operate the same upside-down as they do the right way
>>>> up — they don’t stall and fuss with fuelling issues when you turn them
>>>> over. They also perform the same at 40,000 feet as they do at 4 feet.
>>>> Traditional engines require complex mixture and timing adjustments to keep
>>>> them performing well in the thin atmosphere in which they spend much of
>>>> their lives.
>>>
>>>
>>> about the airplane,
>>>
>>>> Based on a thoroughly modern, but not deeply exceptional structure –
>>>> with a mixture of a steel fuselage and carbon fibre wings, the Extra is
>>>> itself a popular aerobatic model
>>>
>>>
>>>
>>>> The Extra 330LE, which weighs nearly 1,000 kilograms, serves as a
>>>> flying test bed for the new propulsion system. As an aerobatic airplane,
>>>> it's particularly well suited for taking the components to their limits,
>>>> testing them and enhancing their design.
>>>
>>>
>>> the future
>>>
>>>> Electric drives are scalable, and Siemens and Airbus will be using the
>>>> record-setting motor as a basis for developing regional airliners powered
>>>> by hybrid-electric propulsion systems. "By 2030, we expect to see initial
>>>> aircraft with up to 100 passengers and a range of around 1,000 kilometers,"
>>>> explained Anton.
>>>
>>>
>>>
>>> I love this anecdote about intelligent analysis tools in CAD. (*hi
>>> cad-discuss, that's why you're cc'd :]* )
>>>
>>> The end-shield for the motor, for example, was analyzed using a *software
>>>> package* that divided the component into over 100,000 elements, each
>>>> of which was individually further stress-analyzed and subject to*
>>>> iterative improvement loops.* Eventually, the custom software spat out
>>>> a filigree structure that weighs 4.9kg instead of the 10.5kg from the
>>>> previous design.
>>>
>>>
>>> more about the motor
>>> http://phys.org/news/2015-04-world-record-electric-motor-aircraft.html
>>>
>>> Siemens researchers have developed a new type of electric motor that,
>>>> with a weight of just 50 kilograms, delivers a* continuous output of
>>>> about 260 kilowatts – five times more than comparable drive systems.*
>>>> The motor has been *specially designed* for use in aircraft. Thanks to
>>>> its record-setting power-to-weight ratio, larger aircraft with *takeoff
>>>> weights of up to two tons* will now be able to* use electric drives
>>>> for the first time.*
>>>>
>>>
>>>
>>>> New simulation techniques and sophisticated lightweight construction
>>>> enabled the drive system to achieve a unique weight-to-performance ratio of
>>>> five kilowatts (kW) per kilogram (kg). *The electric motors of
>>>> comparable strength that are used in industrial applications deliver less
>>>> than one kW per kg. The performance of the drive systems used in electric
>>>> vehicles is about two kW per kg.* Since the new motor delivers its
>>>> record-setting performance at rotational speeds of just* 2,500
>>>> revolutions per minute, it can drive propellers directly, without the use
>>>> of a transmission.*
>>>>
>>>> In the next step, the Siemens researchers will boost output further.
>>>> "We're convinced that the use of hybrid-electric drives in regional
>>>> airliners with 50 to 100 passengers is a real medium-term possibility,"
>>>> said Anton.
>>>
>>>
>>>
>>> this might be what the motor looks like? not sure
>>> https://youtu.be/j3cNLsN-eCM?t=31s
>>> [image: Inline image 1]
>>>
>>>
>>>
>>> about the Siemens and electric dirigibles (?!)
>>>
>>>>
>>>
>>> Siemens current motor is sufficient to power a small 4-seater aircraft
>>>> by itself. Indeed, it would be “quite racy” suggest Siemens in that
>>>> application. And Siemens is keen to point out that the motor is *nearing
>>>> the power requirements for small regional airliners. *Of course if
>>>> anyone would know about aeronautical electric motors it really ought to be
>>>> Siemens, given that it was its electric motor that (back in 1881) powered
>>>> the *first electric dirigible*
>>>> <https://archive.org/details/lesballonsdirig00tissgoog>*.*
>>>
>>>
>>> Also check out this amazing scan of an* 1885 book about electric
>>> dirigibles*. (archive.org's ebook software is on-point!)
>>> https://archive.org/details/lesballonsdirig00tissgoog
>>>
>>>> Dirigibles: application of electricity to air navigation
>>>
>>> by Gaston Tissandier
>>>> Published 1885
>>>> Book digitized by Google from the library of the University of Michigan
>>>> and uploaded to the Internet Archive by user tpb.
>>>
>>>
>>>
>>> Thanks,
>>> --Nancy
>>>
>>>    -
>>>
>>>
>
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