Four engine - Electric Cri Cri

Discussion in 'Firewall Forward / Props / Fuel system' started by Rienk, Sep 9, 2010.

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  1. Sep 9, 2010 #1

    Rienk

    Rienk

    Rienk

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    First Flight For Four-Engine Electric Airplane

    [​IMG]

    The tiny all-electric four-engine aerobatic aircraft known as Cri-Cri, which is "cricket" in French, has flown for the first time, EADS has announced. The company's Innovation Works developed the airplane together with Aero Composites Saintonge and the Green Cri-Cri Association. The first flight launched from Le Bourget airport near Paris last Thursday morning. "Take-off and climb were smooth, no vibrations could be felt and maneuverability was excellent," EADS said in a statement. The project may seem like pure fun, but it has a serious purpose, according to Jean Botti, EADS's chief technical officer. "The Cri-Cri is a low-cost test bed for system integration of electrical technologies in support of projects like our hybrid propulsion concept for helicopters," he said. "We hope to get a lot of useful information out of this project."

    The airplane is built of lightweight composite structures to compensate for the additional weight of the batteries, and four brushless electric motors with counter-rotating propellers deliver propulsion with zero CO2 emissions and significantly lower noise compared to thermal propulsion, EADS says. The system is powered by high-energy-density lithium batteries. The company aims for Cri-Cri to deliver 30 minutes of cruise flight at 60 knots, 15 minutes of aerobatics at speeds reaching up to 135 knots, and a climb rate of approximately 1,000 feet per minute. The aircraft was displayed in June at the Green Aviation Show at Le Bourget. It is based on a French homebuilt design from the 1970s.
     
  2. Sep 9, 2010 #2

    Topaz

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    They built an all-composite Cri-Cri? And redesigning all the structure like that is "low-cost"?

    Only in a typically corporate "reality" could both of those statements be true. :roll:
     
  3. Sep 10, 2010 #3

    MadRocketScientist

    MadRocketScientist

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    I think at a guess is that all they have done is make all the composite fairings out of carbon.

    I am not sure if you could get it much lighter than 0.020" alloy as it is.

    Shannon.
     
  4. Sep 10, 2010 #4

    Rienk

    Rienk

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    What is the weight of .020" AL?
    I figured it weighs about .28 lb/sf. Is that right?
    We get our fiberglass laminates (9oz - 2mm core - 9 oz) to come in at about .36 lb/sf. CF can be stronger and lighter, as would honeycomb. It wouldn't surprise me if a lightweight composite panel could be made for about the same weight as the AL, and exponentially stronger/stiffer.

    I think the CriCri is a neat little bird... I wonder what it would be like to fabricate it out of precut panels of composite it instead? Sure a lot less bonding time (compared to rivets). It would assuredly be a little heavier - but it would be built like a tank.

    I'm pondering what a composite paneled design would be like... maybe like the typical light wood planes, without all the extra bracing. Might be an interesting study. I know the Vision and Personal Cruiser use a sandwich approach, but that needs to be glassed up by hand.
    What if you used composite panels like plywood? Hmmmm.... something the size of the Cri Cri would be an inexpensive way to try it out.
     
  5. Sep 10, 2010 #5

    MadRocketScientist

    MadRocketScientist

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    The newer MC-30 Luciole is made using similar structural methods to the CriCri but in plywood.

    Most of the minimalist aircraft need to be pretty close to being optimized for their particular materials choice. Theres only so much weight you can remove off a 75kg aerobatic airframe and have anything left:gig:

    Shannon.
     
  6. Nov 17, 2010 #6

    Starflight

    Starflight

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    I like the multi engine concept, but didn't configure it like that.
    BTW- the Luciole has a 22 foot wing with a thinner turbulent
    profile; the original Wortmann 21+ % 16ft span wing had to
    work too hard(AOA)to overcome induced drag.
     
  7. Dec 22, 2010 #7

    topspeed100

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    IMHO the EADS Cri Cri actually doubled the engines compared to one of the previous attempts. Pics are at my blog. So making it composite wasn't necessarily lighter.
     
  8. Dec 22, 2010 #8

    Jan Carlsson

    Jan Carlsson

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    High AOA is inducing large induced drag, it has nothing to do with the airfoil. at cruise the induced drag is small, at best L/D speed the induced drag Di is just as big as the parasit drag Do.

    Jan
     

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