MartinW 0 Posted June 26, 2015 Report Share Posted June 26, 2015 NASA has made some expansive claims about the high efficiency, low noise and emissions and overall transformative potential of electric aircraft propulsion. Now its engineers are being given the chance to show whether those claims are supportable.The research agency has approved a three-year, $15 million project to fly a distributed electric propulsion (DEP) X-plane. The demonstrator will be based on a light general-aviation aircraft but, if the technology proves out, NASA has aggressive plans to follow up with a nine-seat commuter demonstrator that could pave the way for a 60-90-seat hybrid-electric regional airliner. The project will convert an Italian Tecnam P2600T piston-powered light twin to distributed electric propulsion, where batteries will power 10-12 small electrically driven propellers arrayed along the leading edge of the wing. These props will induce higher airflow velocity over the wing, increasing lift at lower airspeeds and enabling wing area to be reduced dramatically, for higher efficiency in cruise. The program is a four-phase effort that will lead to flight tests of the X-plane in 2017. The primary goal is to demonstrate a five-fold reduction in energy use in cruise, thanks to the smaller wing and other features. “The minimum threshold is 3.5 times,” says Mark Moore, NASA principal investigator on the project.Those savings come from two things. The shift from hydrocarbon combustion to electric propulsion will increase energy conversion efficiency to 92% from 28%. “That’s a 2.9-3.3-times improvement simply from the electric motors,” said Moore, speaking at the AIAA Aviation 2015 forum in Dallas on June 23. Another 1.2-1.5-times improvement in energy consumption will come from the integration of DEP and the synergistic coupling of aerodynamics and propulsion, he says. http://aviationweek.com/technology/nasa-electric-propulsion-x-plane-just-first-step Link to post Share on other sites
MartinW 0 Posted June 26, 2015 Author Report Share Posted June 26, 2015 The X-plane demonstrator will be a Tecnam P2600T light piston twin modified with a distributed electric propulsion wing. Credit: NASA Link to post Share on other sites
wain 879 Posted June 26, 2015 Report Share Posted June 26, 2015 Right...but whats the weight of any battery pack required? Whats the expected range? I am not convince by this tech yet... I know someone posted about batteries the other week but that is still in developement....battery tech is the one thing holding everything back including cars...phones...pc....etc.... Oh and please dont give me all the less pollution stuf..electric comes from somewhere and quite often its ceation is as bad as the engine etc... Will be good if it ever works but I wouldnt want to try it..... Wayne Link to post Share on other sites
MartinW 0 Posted June 26, 2015 Author Report Share Posted June 26, 2015 Right...but whats the weight of any battery pack required? Whats the expected range? I am not convince by this tech yet... I know someone posted about batteries the other week but that is still in developement....battery tech is the one thing holding everything back including cars...phones...pc....etc.... You are right not to be convinced yet. It's early days, these aircraft are merely concept demonstrators. The batteries weigh something yes, minus the weight of a couple of hefty internal combustion engines and fuel tanks. And if direct drive, minus the weight of a transmission. It's the advent of improved lithium-polymer batteries that's making hybrid and electric aircraft viable. Oh and please dont give me all the less pollution stuf..electric comes from somewhere and quite often its ceation is as bad as the engine etc... True, an electric car or aircraft charged from the mains will probably derive it's power from coal fired power stations. Even so, that's still more efficient, as internal combustion engines are very inefficient. Obviously if your power is generated from renewables or nuclear that's a better option. This will be a prototype though, so the intention is to demonstrate that NASA's claims regarding the technologies capabilities are valid. Primarily at this stage it's the DEP system they will be validating I suspect, the capability of DEP to generate more lift and be more efficient. Ultimately, the intention is for the final product to be a hybrid, a small IC generator plus electric motors. So your concerns regarding where the electricity comes from won't be relevant. There are many manufacturers exploring hybrid technology at the moment. And it's already been demonstrated last year, that such technology can render an aircraft 30% more efficient. Last years test aircraft was developed in a calboration between Cambridge University and Boeing. http://www.dailymail.co.uk/news/article-2888494/Is-world-s-green-aircraft-New-hybrid-plane-electric-motor-successfully-tested-stay-airborne-minutes.html It's an area that's developing fast. Jaguar have a super small light weight IC generator in development to charge aircraft batteries. Siemens have achieved a world record with their electric motor designed for aircraft. It weighs just 50KG and generates 350hp. They say the new electric motor has enough grunt for aircraft with a takeoff weight up to two tons. It's direct drive, so it doesn't require a heavy transmission. http://www.gizmag.com/siemens-world-record-electric-motor-aircraft/37048/ "This innovation will make it possible to build series hybrid-electric aircraft with four or more seats," said Frank Anton, Head of eAircraft at Siemens Corporate Technology, the company's central research unit. "We're convinced that the use of hybrid-electric drives in regional airliners with 50 to 100 passengers is a real medium-term possibility." If you doubt this technology is going somewhere, then you might be interested to learn, that regarding the Airbus E-Fan... Construction of the E-Fan assembly line is expected to begin next year. The first E-Fan 2.0 is set to make its maiden flight in late 2017, followed by the series aircraft rolling out to customers the year after. An initial production rate of 10 aircraft per year has been targeted, with the facility capable of growth depending on market demand. http://www.gizmag.com/airbus-e-fan-2-paris-air-show-2015/38068/ Link to post Share on other sites
wain 879 Posted June 26, 2015 Report Share Posted June 26, 2015 I have to agree these are indeed changing times..I believe once developed fully and tested thoroughly we may gain in confidence with regards to trusting these...I think it will come eventually but in who's lifetime I am not sure... It wouldnt be the same though seeing a Chinook without hearing the fantastic engine noise, that was always a great sound, it meant pickup or reinforcements.. Wayne Link to post Share on other sites
dodgy-alan 1,587 Posted June 26, 2015 Report Share Posted June 26, 2015 That first aircraft reminds me of one of those kids toy planes that we used to throw around in the park! I had some elecrtic powered RC aircraft including helicopters,(still got a couple somewhere). They were powered by simply charging them up for a few hours and then flying them. Now if they can scale up that tech to a full sized aircraft it could be interesting. I'm assuming it would need a big accumulator on board to take the charge but hey, it may work though i'm very sceptical. Link to post Share on other sites
MartinW 0 Posted June 26, 2015 Author Report Share Posted June 26, 2015 I have to agree these are indeed changing times..I believe once developed fully and tested thoroughly we may gain in confidence with regards to trusting these...I think it will come eventually but in who's lifetime I am not sure... It wouldnt be the same though seeing a Chinook without hearing the fantastic engine noise, that was always a great sound, it meant pickup or reinforcements.. Wayne A few years Wayne. The E-Fan is 2017. E-Fan 4.0 hybrid electric 2019. E-Thrust, a Proposed 90-seat regional jet based on the principles of the E-Fan after that. https://en.wikipedia.org/wiki/Airbus_E-Fan The Diamond DA-36 E-Star 2 isn't far off either. Link to post Share on other sites
Captain Coffee 2,030 Posted June 26, 2015 Report Share Posted June 26, 2015 I like the part about lots of small props forcing high velocity airflow over the wings...this sound like an Incredibly Good idea on a couple levels. Smaller props mean less weight spinning/reduced vibration/less catastrophic results if one fails/cheaper to produce/replace. And for the forced AOA improvement at any speed due to the forced airflow generated by the bank of motors arrayed along the length of the wing. I am looking forward to finding out how those factors play out in this. Link to post Share on other sites
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