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

[Lochie Ferrier]

Couple of notes:

   - Hydrogen is hard, because the drag of the large tanks is enough to
   drop L/D down by enough to make the benefit questionable.
   - It's not the desire to fly 500 miles, it's the need as given by
   city-pair distances and the tight competition of the airline market (the
   cost of layovers is very significant, and electric can only get out in
   front economically if you don't have them)
   - The gallium aluminum system is definitely encouraging, according to
   someone I know who has worked on it it can reach specific energy of order
   of mag higher than Li-ion (~31 MJ/kg vs 0.72 MJ/kg). Current Jet A-1 comes
   in at 42.8 MJ/kg. Studying whether the fuel cell conversion system
   diminishes this benefit in the airliner environment would be a super good
   idea.
   - On the oil cooling thing, NASA has tried out cryogenically cooled
   motors and achieved good but not insane energy densities that I think were
   shown on Nancy's plot.
   - To be clear, the climate change impact of aviation is not that great.
   Likely not higher than 5% of transportation (science is not in on what H2O
   emissions do at altitude), let alone everything. So the motivation should
   really be building a better plane, not reducing emissions, in which case
   you want range, low cost and all the other things.

Cool to see that people are thinking about this, because quiet,
low-maintenance, cheap-to-run planes will shake things up.

On Wed, 13 Jul 2016 at 10:27 damon vanderlind <damonvl at gmail.com> wrote:

> The approach is to have a closed shell around the stator such that the oil
> does not enter the airgap. This increases the airgap by a portion of a
> millimeter. This will have some variable effect based on the type of magnet
> and the machine design.
>
> Usually something akin to a transformer oil is good to use. I have used
> synthetic transformer oils to good effect. Just don't light your engine on
> fire...
>
> --damon
>
> On Tue, Jul 12, 2016 at 5:16 PM, nk <nkirkby.nk at gmail.com> wrote:
>
>> Damon,
>> direct oil cooling on the motors you worked on - is the rotor floating in
>> oil and making viscous losses in the air gap?
>> or oil mist?
>>
>> Nkirkby
>> On Jul 12, 2016 2:43 PM, "damon vanderlind" <damonvl at gmail.com> wrote:
>>
>>> Sorry 'bout that.
>>>
>>> GA: general aviation
>>>
>>> Cheating: just a matter of price. If it's really expensive to use these
>>> materials maybe you don't want them for your electric aircraft. Like, why
>>> aren't airliners 100% titanium? It's a great material, but expensive to buy
>>> and machine
>>>
>>> 4 kW: just to point out you can do OK with avoiding the rare materials.
>>> I worked on some 120 kW 32 kg motors (~4 kW/kg), that also did 1000 N*m
>>> torque, without using anything particularly exotic. They were also direct
>>> oil cooled, which the Siemens motors are.
>>>
>>> On Tue, Jul 12, 2016 at 11:39 AM, Nancy Ouyang <nancy.ouyang at gmail.com>
>>> wrote:
>>>
>>>> wtf is GA
>>>> why is it cheating to use crazy materials / power for first-in-class
>>>> motor, &
>>>> are you giving the example of 4 kw to contrast with their 5.2 kw
>>>> techiniques, or to ...?
>>>>
>>>> if people write lengthier emails, it will help silly me understand what
>>>> you are talking about <3
>>>>
>>>>
>>>> ~~~
>>>> my personal blog <http://www.orangenarwhals.com>, orangenarwhals
>>>>
>>>> On Tue, Jul 12, 2016 at 2:33 PM, damon vanderlind <damonvl at gmail.com>
>>>> wrote:
>>>>
>>>>> The batteries aren't that bad... people just need to stop caring if
>>>>> they can fly 500 miles.
>>>>>
>>>>> Siemens kind of cheats for their motors, though I think they are very
>>>>> nice. They use hyperco 50 steel and really high switching frequencies. For
>>>>> now, it prices the devices outside of GA even.  4 kw/kg can be built very
>>>>> cheap, without rare materials and 1000 hours of wire edm time.
>>>>>
>>>>> Cheers
>>>>> --damon
>>>>>
>>>>> On Tue, Jul 12, 2016 at 7:16 AM, Josh Vekhter <vekhterjr at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hmm, perhaps electric planes would actually be a reasonable
>>>>>> application of that crazy aluminum galium thang the Marines are working on?
>>>>>>
>>>>>> Certianly makes more sense on an infrastructure level than fuel cell
>>>>>> cars.
>>>>>>
>>>>>> Energy density of the fuel is supposed to be very good, idk anything
>>>>>> about how much a 100 kw hydrogen fuel cell would weigh.
>>>>>>
>>>>>> Could always make hindenburg 2.0 :P.  Fuel could generate lift!
>>>>>> On Jul 12, 2016 8:05 AM, "Lochie Ferrier" <lochieferrier at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> 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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