fly_tornado Posted April 17, 2015 Share Posted April 17, 2015 http://phys.org/news/2015-04-world-record-electric-motor-aircraft.html 1 Link to comment Share on other sites More sharing options...
kasper Posted April 17, 2015 Share Posted April 17, 2015 Now lets ask them to put that level of power to weight into a 50-70 kw engine and we are talking about an engine comparable in power to the 582-912 bracket at an motor mass of 15-20kg. The mass from 50L petrol plus 912 less the electric motor and for same overall mass you have an allowance for batteries of around 80kg ... energy density in the existing batteries would give you more than the hours that the first production electric two seater - Alpha Electro from Pipistrel ... Link to comment Share on other sites More sharing options...
fly_tornado Posted April 17, 2015 Author Share Posted April 17, 2015 It wont take long to scale down the technology for quad copter type drones Link to comment Share on other sites More sharing options...
facthunter Posted April 17, 2015 Share Posted April 17, 2015 The battery will be the problem. Power for mass and how safe from meltdown they are. I have even had big lead acid batteries cook themselves and they have nowhere near enough power density for practical endurance . Nev 1 Link to comment Share on other sites More sharing options...
kasper Posted April 17, 2015 Share Posted April 17, 2015 Well I can get an off the shelf direct drive electric motor in the 447 power range (30kw peak, 25 continuous) with controller for under 10kg ... its just the batteries that stump me ... price n weight ... oh and the personally required parachute just in case the LiPos go a little 'fire happy' in the air :-/ If it were not for the fact that I already have the F23 and the cost of the batteries/motor are so high I would be happy to give the old sapphire another make-over and turn her electric instead of just moving from 28hp to the 50 of the F23 conversion. As its a 95.10 low weight thick wing sapphire (just under 135kg with 28hp engine) it both has the lift to fly on really modest power and the depth within the wing to put the batteries but I just can't justify the spend so the electric sapphire is sitting in system drawings and specs with costings ... maybe one day. 2 Link to comment Share on other sites More sharing options...
fly_tornado Posted April 17, 2015 Author Share Posted April 17, 2015 I was reading about a new aluminium battery under development, sounds like a variation of a massive capacitor. Being aluminium it will be cheap as chips 1 Link to comment Share on other sites More sharing options...
facthunter Posted April 17, 2015 Share Posted April 17, 2015 Doesn't it run molten sodium?. Electro regenerative could work well in a glider. In a good thermal you could get some back. Nev Link to comment Share on other sites More sharing options...
kasper Posted April 17, 2015 Share Posted April 17, 2015 I was reading about a new aluminium battery under development, sounds like a variation of a massive capacitor. Being aluminium it will be cheap as chips Hmmm was that an ultracapacitor (Canadian) or the sacrificial aluminium/air 'batteries' that are really single life fuel cells (aluminium + electrolyte (water) + oxygen = electricity + aluminium hydroxide)? The ultra capacitors have been hyped and sold as just around the corner for decades while the aluminium/air battery/fuel cell has a shorter history ... but from a 'green' perspective the power that went into the aluminium to produce the battery/fuel cell and the fact its not rechargable makes it quite un-green at the moment ... though the aluminium hydroxide is able to be reprocessed into aluminium again ... but with the same high energy input that was needed to create it in the first place. 1 Link to comment Share on other sites More sharing options...
kasper Posted April 17, 2015 Share Posted April 17, 2015 Oh or you could scrape the hydroxide gel out of the case - wait for it to crystalise and then just consume when you have an upset tummy - its not every battery that produces as its byproduct Gaviscon :-) 1 Link to comment Share on other sites More sharing options...
Downunder Posted April 17, 2015 Share Posted April 17, 2015 Sounds like you're anti electric Nev? Those that worry about battery fires forget we currently and happily fly with tens of litres of a flammable, volatile liquid substance called petrol. We put procedures in place to limit our risks but sometimes sh*t happens. Not doubt in the future, electric flight will become common place and again, safety procedures will be in place to limit the risk. 1 1 Link to comment Share on other sites More sharing options...
kasper Posted April 17, 2015 Share Posted April 17, 2015 Sounds like you're anti electric Nev?Those that worry about battery fires forget we currently and happily fly with tens of litres of a flammable, volatile liquid substance called petrol. We put procedures in place to limit our risks but sometimes sh*t happens. Not doubt in the future, electric flight will become common place and again, safety procedures will be in place to limit the risk. Yeah but if I am putting LiPo batteries inside a fabric wing with a wooden spar ... ever seen lithium burn? It aint gonna blow out no matter how much I point the nose at the ground to get a bit more wind ... 1 Link to comment Share on other sites More sharing options...
spacesailor Posted April 17, 2015 Share Posted April 17, 2015 Li-fe-po Perhaps the newer lifepo batteries, would be better (for everything) as soon as the price reduces, to reasonable level. spacesailor Link to comment Share on other sites More sharing options...
503 Posted April 17, 2015 Share Posted April 17, 2015 Tesla had it sorted long ago , no battery's required Link to comment Share on other sites More sharing options...
Downunder Posted April 17, 2015 Share Posted April 17, 2015 Yeah but if I am putting LiPo batteries inside a fabric wing with a wooden spar ... ever seen lithium burn? It aint gonna blow out no matter how much I point the nose at the ground to get a bit more wind ... Part of the safety procedure may be "No wooden spars or fabric..." Link to comment Share on other sites More sharing options...
cooperplace Posted April 17, 2015 Share Posted April 17, 2015 no battery required: do you mean petrol? a glider? Link to comment Share on other sites More sharing options...
Marty_d Posted April 17, 2015 Share Posted April 17, 2015 Powered glider with solar panels on the wing. Only using the engine for takeoff and occasionally maintaining height so batteries don't need to be huge. It wouldn't be a particularly fast aircraft, but should be able to pootle around all day in the sunshine.... 1 1 Link to comment Share on other sites More sharing options...
facthunter Posted April 18, 2015 Share Posted April 18, 2015 Downunder. No I'm not anti electric. I don't believe we are there with batteries by a mile yet, except for interesting little fun stuff hybrid gliders etc. You just don't have the energy/weight equation right to go vast distances at any great speed and payload. Hydrocarbons stored aren't a serious threat, and you can even dump tonnes of fuel safely done properly, although a litre of it properly mixed with air would blow the average house apart.. Nev Link to comment Share on other sites More sharing options...
cooperplace Posted April 18, 2015 Share Posted April 18, 2015 Powered glider with solar panels on the wing. Only using the engine for takeoff and occasionally maintaining height so batteries don't need to be huge. It wouldn't be a particularly fast aircraft, but should be able to pootle around all day in the sunshine.... sounds fantastic, usually there's no shortage of sunshine here Link to comment Share on other sites More sharing options...
Marty_d Posted April 18, 2015 Share Posted April 18, 2015 I don't think we're supposed to fly at night or in IMC anyway... 1 Link to comment Share on other sites More sharing options...
spacesailor Posted April 18, 2015 Share Posted April 18, 2015 No wood or fabric?, Aluminium Burns brighter than a Hindenburg (Luftschiff Zeppelin #129; Registration: D-LZ 129), The English found this out in the Falcons war. Link to comment Share on other sites More sharing options...
Old Koreelah Posted April 18, 2015 Share Posted April 18, 2015 Part of the safety procedure may be "No wooden spars or fabric..." In the event of a battery fire wood is safer than metal. Wood chars and eventually burns. Aluminium rapidly heats, loses rigidity, folds up...then burns violently. Link to comment Share on other sites More sharing options...
kasper Posted April 18, 2015 Share Posted April 18, 2015 Part of the safety procedure may be "No wooden spars or fabric..." what safety process? this is 95.10 I'm saving paddle pop sticks for the new spars :-P 2 Link to comment Share on other sites More sharing options...
Downunder Posted April 18, 2015 Share Posted April 18, 2015 I think you're all taking me out of context (or winding me up?). What I'm saying is that there are measures to mitigate the risks of petrol and there would be measures to limit the risks for batteries....None perfect..... 1 Link to comment Share on other sites More sharing options...
Old Koreelah Posted April 18, 2015 Share Posted April 18, 2015 Electric power for aircraft frees up designers from the traditional constraints of heavy engine, liquid fuel. Being so light, engine, prop. and batteries can be put just about anywhere. Battery packs could be plugged into the rear of wings or fuselage for easy swapping...or ejection in the event of fire. Link to comment Share on other sites More sharing options...
facthunter Posted April 19, 2015 Share Posted April 19, 2015 It's never been legal to purposely dump bits from an aircraft. Batteries are a concern even with present usage and are monitored and often accessible in flight. Nev Link to comment Share on other sites More sharing options...
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