<p dir="ltr">Hmm, perhaps electric planes would actually be a reasonable application of that crazy aluminum galium thang the Marines are working on?</p>
<p dir="ltr">Certianly makes more sense on an infrastructure level than fuel cell cars.</p>
<p dir="ltr">Energy density of the fuel is supposed to be very good, idk anything about how much a 100 kw hydrogen fuel cell would weigh.</p>
<p dir="ltr">Could always make hindenburg 2.0 :P. Fuel could generate lift!</p>
<div class="gmail_quote">On Jul 12, 2016 8:05 AM, "Lochie Ferrier" <<a href="mailto:lochieferrier@gmail.com">lochieferrier@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">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 (<a href="http://www6.miami.edu/acfdlab/publications/AIAA-2015-0772.pdf" target="_blank">co-flow airfoil</a>, or <a href="http://web.mit.edu/drela/Public/N+3/Uranga2014_compressed.pdf" target="_blank">BLI</a>), 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 <a href="https://en.wikipedia.org/wiki/Musk_electric_jet" target="_blank">Musk electric jet</a> 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 <i>supersonic. </i><font size="2"><a href="http://web.mit.edu/lochie/www/erange/main.html" target="_blank">Play around with the numbers</a>, and you'll hopefully see what I mean.</font><div><i><br></i></div><div><font size="2">There's very little way of getting around the fact that batteries are approximately 100x heavier than kerosene on energy basis.</font></div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, 12 Jul 2016 at 18:46 Nancy Ouyang <<a href="mailto:nancy.ouyang@gmail.com" target="_blank">nancy.ouyang@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>sweet pdf, though lol loweffort response :p yes ofc batteries</div><div><br></div><div>I believe the PDF is 2012 (why oh why don't people put date writtens or at least year written in their documents)</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">The few electric motors available toda<b>y for aircraft propulsion
</b>have a power output of <b>less than 100 kW</b>. 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 <b>specific mass of about 2 to 4 kW/kg</b>. This compares favorably with the specific mass of larger
turboshaft and turbofan engines at cruise power (see Figure 13 and Figure 14). <b>Future developments</b> may
extend the range of electric motors to values of <b>up to 8 kW/kg</b>, but there is a strong need for the
development of lightweight electric motors, specifically designed for application in aircraft.<br></blockquote><div><br></div><div>so this gives context to why siemen's motor is cool.</div><div><br></div><div>260 kW / 50 kg =<b> 5.2 @ 260 kW</b> or roughly <b>orange</b> circle:</div><div><br></div><div><img src="cid:ii_155de3f48294af4d" alt="Inline image 1" width="563" height="242"><br></div><div>pg 12<br></div><div><br></div><b>does anyone know what the comparable previous weight would be before this motor? </b>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.<div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">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. </blockquote><div><br></div><div>I love their <b>"let's think through how we'd make this work" thought experiment</b> section:</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Applying this simulation model to a specific aircraft allows determining the possible performance and the
technology improvements required to achieve the desired results </blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">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 </blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">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.</blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">The next modification would reduce the empty
mass of the aircraft by 20%. This would require
introducing extreme lightweight design features </blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">This step improves the battery technology by
doubling the mass specific energy * E . <b>Such an
improvement is quite well possible with future
development of Li-S battery systems within the
next 15 years</b>.
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. </blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Furthermore new
infrastructure to replace and recharge the batteries
on each airport would be required to make such an
aircraft feasible </blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">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</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br>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. </blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"> </blockquote><div>(This last stat is mostly due to how light and dragless the author's thought-experiment is, I think.)</div><div><br></div><div>Thanks,</div><div>--Nancy</div></div><div class="gmail_extra"><br clear="all"><div><div data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><font size="2"><font color="#666666">~~~<br></font></font><a href="http://www.orangenarwhals.com" style="font-size:12.8000001907349px" target="_blank">my personal blog</a><span style="color:rgb(102,102,102);font-size:12.8000001907349px">, orangenarwhals</span></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><div class="gmail_extra">
<br><div class="gmail_quote">On Tue, Jul 12, 2016 at 2:48 AM, Lochie Ferrier <span dir="ltr"><<a href="mailto:lochieferrier@gmail.com" target="_blank">lochieferrier@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">The batteries though. The batteries are what makes it <a href="http://www.mh-aerotools.de/company/paper_14/MP-AVT-209-09.pdf" target="_blank">super hard</a>.</div><div><div><br><div class="gmail_quote"><div dir="ltr">On Tue, 12 Jul 2016 at 16:31 Nancy Ouyang <<a href="mailto:nancy.ouyang@gmail.com" target="_blank">nancy.ouyang@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><p style="font-size:13px;color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;line-height:17px;margin:0px;padding:0px;border:0px;background-image:initial;background-color:transparent;background-repeat:initial"><a href="http://www.siemens.com/press/electric-aircraft" target="_blank">www.siemens.com/press/electric-aircraft</a></p><p style="font-size:13px;color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;line-height:17px;margin:0px;padding:0px;border:0px;background-image:initial;background-color:transparent;background-repeat:initial"></p><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="font-family:Arial,Geneva,Helvetica,sans-serif;font-size:11px;line-height:16px"><b>"This is the first time that an electric aircraft in the quarter-megawatt performance class has flown."</b></span></blockquote><p></p></div><div><br></div><a href="https://www.youtube.com/watch?v=fiu8TFnXYFY" target="_blank">https://www.youtube.com/watch?v=fiu8TFnXYFY</a><div><br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;font-size:13px;line-height:17px">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.</span></blockquote>
<div><div style="margin:0px;padding:0px;border:0px;background-image:initial;background-repeat:initial"><p style="color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;font-size:13px;line-height:17px;margin:0px;padding:0px;border:0px;background-image:initial;background-color:transparent;background-repeat:initial"></p><div> </div><div>Datasheet: <a href="http://www.siemens.com/press/pool/de/feature/2015/corporate/2015-03-electromotor/factsheet-erstflug-weltrekordmotor-d.pdf" target="_blank">http://www.siemens.com/press/pool/de/feature/2015/corporate/2015-03-electromotor/factsheet-erstflug-weltrekordmotor-d.pdf</a><br></div><p></p><div style="color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;font-size:13px;line-height:17px"><br></div><div><font color="#333333" face="Roboto, arial, sans-serif"><span style="line-height:17px"><a href="https://transportevolved.com/2016/07/08/siemens-showcases-brand-new-electric-motor-thats-super-light-super-powerful-and-perfect-for-electric-airplanes/" target="_blank">https://transportevolved.com/2016/07/08/siemens-showcases-brand-new-electric-motor-thats-super-light-super-powerful-and-perfect-for-electric-airplanes/</a></span></font><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px">Of course, electric motors have long been used in model planes, but their use outside the 1:14</span><sup style="color:rgb(59,59,59);font-family:Ubuntu">th</sup><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px"> 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.</span></blockquote><div><br></div><blockquote style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex" class="gmail_quote">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.<br></blockquote><div> </div><blockquote style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex" class="gmail_quote">But there are also other benefits that are deeply exciting for aeronautical engineers and pilots.</blockquote><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:1.6">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.</span></blockquote><div> </div><div>about the airplane,</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px">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</span></blockquote><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(51,51,51);font-family:Arial,Geneva,Helvetica,sans-serif;font-size:11px;line-height:16px">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.</span> </blockquote><div><br></div><div>the future</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(51,51,51);font-family:Arial,Geneva,Helvetica,sans-serif;font-size:11px;line-height:16px">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.</span></blockquote><div><br></div><div><br></div><div>I love this anecdote about intelligent analysis tools in CAD. (<b>hi cad-discuss, that's why you're cc'd :]</b> )</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px">The end-shield for the motor, for example, was analyzed using a <b>software package</b> that divided the component into over 100,000 elements, each of which was individually further stress-analyzed and subject to<b> iterative improvement loops.</b> Eventually, the custom software spat out a filigree structure that weighs 4.9kg instead of the 10.5kg from the previous design.</span><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px"> </span> </blockquote><div> </div><div>more about the motor <a href="http://phys.org/news/2015-04-world-record-electric-motor-aircraft.html" target="_blank">http://phys.org/news/2015-04-world-record-electric-motor-aircraft.html</a></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(0,0,0);font-family:Arial,Helvetica,sans-serif;font-size:14px">Siemens researchers have developed a new type of electric motor that, with a weight of just 50 kilograms, delivers a<b> continuous output of about 260 kilowatts – five times more than comparable drive systems.</b> The motor has been <b>specially designed</b> for use in aircraft. Thanks to its record-setting power-to-weight ratio, larger aircraft with <b>takeoff weights of up to two tons</b> will now be able to<b> use electric drives for the first time.</b></span><br></blockquote><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(0,0,0);font-family:Arial,Helvetica,sans-serif;font-size:14px">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). <b>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.</b> Since the new motor delivers its record-setting performance at rotational speeds of just<b> 2,500 revolutions per minute, it can drive propellers directly, without the use of a transmission.</b></span><br style="color:rgb(0,0,0);font-family:Arial,Helvetica,sans-serif;font-size:14px"><br style="color:rgb(0,0,0);font-family:Arial,Helvetica,sans-serif;font-size:14px"><span style="color:rgb(0,0,0);font-family:Arial,Helvetica,sans-serif;font-size:14px">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.</span></blockquote><div><br></div><div><br></div><div>this might be what the motor looks like? not sure</div><div><a href="https://youtu.be/j3cNLsN-eCM?t=31s" target="_blank">https://youtu.be/j3cNLsN-eCM?t=31s</a><br></div><div><img src="cid:ii_155ddcc59ed56c5c" alt="Inline image 1" width="413" height="263"><br></div><div><br></div><div> </div><div><div> </div><div><font size="4">about the Siemens and electric dirigibles (?!)</font></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"> </blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px">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 <b>nearing the power requirements for small regional airliners. </b>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) </span><a href="https://archive.org/details/lesballonsdirig00tissgoog" style="color:rgb(33,58,122);text-decoration:none;line-height:22.4px;font-family:Ubuntu;font-size:14px" target="_blank">powered the <b>first electric dirigible</b></a><span style="color:rgb(59,59,59);font-family:Ubuntu;font-size:14px;line-height:22.4px"><b>.</b></span></blockquote><div> </div></div><div style="color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;font-size:13px;line-height:17px">Also check out this amazing scan of an<b> 1885 book about electric dirigibles</b>. (<a href="http://archive.org" target="_blank">archive.org</a>'s ebook software is on-point!)</div><div><font color="#333333" face="Roboto, arial, sans-serif"><span style="line-height:17px"><a href="https://archive.org/details/lesballonsdirig00tissgoog" target="_blank">https://archive.org/details/lesballonsdirig00tissgoog</a></span></font><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><font color="#333333" face="Roboto, arial, sans-serif"><span style="line-height:17px">Dirigibles: application of electricity to air navigation</span></font></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">by Gaston Tissandier <br>Published 1885 <br>Book digitized by Google from the library of the University of Michigan and uploaded to the Internet Archive by user tpb.</blockquote><div><br></div><div><br></div><div>Thanks,</div><div>--Nancy </div></div><div style="margin-top:8px;margin-right:0px;margin-left:0px;padding:0px;border:0px;font-size:13px;color:rgb(51,51,51);font-family:Roboto,arial,sans-serif;line-height:17px;margin-bottom:0px!important;background-image:initial;background-repeat:initial"><ul style="list-style:none;margin:0px;padding:0px;border:0px;background:transparent"><li style="margin:0px;padding:0px;border:0px;clear:both;background:transparent"></li></ul></div></div></div></div>
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