Fauvel musings

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by cluttonfred, May 13, 2017.

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  1. May 13, 2017 #1

    cluttonfred

    cluttonfred

    cluttonfred

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    Again and again over the years, when thinking about how to make a very simple, safe, affordable little airplane, I often return to the idea of a Fauvel-type unswept flying wing. Take a look at these images of the Fauvel AV-60 (3-view is actually the slightly later AV-61) from "Charles Fauvel and His Flying Wings" on the great Nurflugel site and Fraser Technology (near bottom of page).

    AV60w5.jpg av60_1.jpg planAV61.gif

    Fauvel AV-60
    Specifications

    Wing Span 7 m
    Length 4 m
    Empty Weight 220 kg
    Max Gross Weight 350 kg
    Maximum Speed 157 km/h
    Cruise speed 128 km/h
    Takeoff Distance 180 m

    There are some pros and cons to Fauvel's tapered wings with separate elevators and ailerons and a simple constant-chord Backstrom-style plank wing with tip elevons also has merit, but either way just look at the simplicity in that cutaway drawing. I know Mike Whittaker is working on his pusher design and I am really looking forward to that, but I also think that a modest, tractor-engined unswept flying wing would make a great low-cost fun flyer.
     
    Last edited: May 13, 2017
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  2. May 13, 2017 #2

    plncraze

    plncraze

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    If the plans were floating around online it would be fun to see what could be done if it was built today. Steal some ideas from the Skypup ultralight and put a cheap engine in it! Fun!
     
  3. May 13, 2017 #3

    Tiger Tim

    Tiger Tim

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    So this but in UL form?
    [​IMG]
     
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  4. May 13, 2017 #4

    cluttonfred

    cluttonfred

    cluttonfred

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    I don't know that I'd go high wing, though that might work with the upper surface above the cockpit covered in something transparent. I think a low wing works better, or maybe mid-wing like a shorter-span, trigear, powered Backstrom EPB-1.

    plank_3.jpg

    PS--This would be a great application for that one-piece Warren truss wing with the pilot sitting in one of the triangular bays that we discussed in another thread.
     
    Last edited: May 13, 2017
  5. May 13, 2017 #5

    FritzW

    FritzW

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    Didn't you (Matthew) buy a set of AV-60 plans a while back?
     
  6. May 13, 2017 #6

    cluttonfred

    cluttonfred

    cluttonfred

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    Nope, wasn't me, though I'd be interested if they were available.
     
  7. May 13, 2017 #7

    Sockmonkey

    Sockmonkey

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    I should elaborate on how I wanted the Warren truss to be.
    [​IMG]
    Loads would be carried by the hollow extrusions fore and aft with no central spar.
     
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  8. May 13, 2017 #8

    Battler Britton

    Battler Britton

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    Hi, Matthew,

    Fauvel AV-60
    Specifications
    Wing Span 7 m
    Length 4 m
    Empty Weight 220 kg
    Max Gross Weight 350 kg
    Maximum Speed 157 km/h
    Cruise speed 128 km/h
    Takeoff Distance 180 m

    I know an avalaible quite similar drawing,that is smaller, lighter, faster, folding, maybe easyer to built...

    ask me! :gig:
     
  9. May 14, 2017 #9

    plncraze

    plncraze

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    I'm asking! What is it? I hope you have pictures.
     
  10. May 14, 2017 #10

    Aerowerx

    Aerowerx

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    IIRC plans are available. On my smartphone here at work so it's clumsy to look it up and post at the same time.
     
  11. May 14, 2017 #11

    Aerowerx

    Aerowerx

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    Just looked. What I remembered was the AV36 glider plans on falconaravia.com.
     
  12. May 14, 2017 #12

    FritzW

    FritzW

    FritzW

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    It was Shawn (spduffee) who bought them, waaay back on this thread.

    I haven't seen him on the HBA lately. He came down with a bad case of TMK (Too Many Kids) so he's out of the airplane building game for a while. He might be willing to part with his copy of the plans.
     
  13. May 14, 2017 #13

    Turbine Aeronautics

    Turbine Aeronautics

    Turbine Aeronautics

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    Or update this little beauty...

    Stingray 1.jpg

    Stingray 2.jpg
     
  14. May 14, 2017 #14

    cluttonfred

    cluttonfred

    cluttonfred

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    Is it the Debreyer JCD 03 Pelican? If so, I would love to get my hands on the plans for the original wood proof-of-concept prototype rather than the later composite kit version. Don't keep us in suspense, I am sure lots of folks here would be interested! ;-)



    Is that a precursor to the Dyke Delta?

     
  15. May 14, 2017 #15

    Sockmonkey

    Sockmonkey

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    The stingray is neat but is it awkward to climb in and out of?
     
  16. May 14, 2017 #16

    plncraze

    plncraze

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    When you look at pictures with the builder remember that he is 5'9" and 210 pounds. It is a small airplane.
     
  17. May 14, 2017 #17

    Turbine Aeronautics

    Turbine Aeronautics

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    It is the Delta Stingray, by Lowell J Borchers. He designed it with the assistance of John Dyke after the Dyke Delta was available.

    Stingray 3.jpg

    Stingray 4.jpg
     
  18. May 14, 2017 #18

    WBNH

    WBNH

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    Wouldn't mind seeing a Fauvel design in person.

    The AV-61 as a taildragger you could predict could get squirrelly with the tailwheel so close coupled.

    Take a lower aspect ratio Fauvel taper, add rounded elevons, stir, and you'd have something akin to Milt Hatfield's Little Bird. A planform I entertained long and hard for a 103 UL...but eventually decided a Flea or Parasol would be preferable for better downward visibility/ultralight sight-seeing. Though the pics in post 1 do put the pilot's eyes close to the leading edge, so perhaps I have to revisit the idea.
     
  19. May 14, 2017 #19

    Riggerrob

    Riggerrob

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    Notice how the Fauvel wing is sharply tapered.
    This taper produces a long root chord, which produces a (comparatively) long tail moment arm. Long tail moment arms reduce sensitivity to variations in loads. Long tail moment arms improve pitch stability and pitch control authority.
    Long root chords also mount the rudder (comparatively) far aft, improving yaw stability.
    Long and deep wing roots also help streamline cockpits.
    Considering the tiny Reynolds numbers at the tips, I suspect that wing tips do little more than displace wing tip vortices farther outboard. I also suspect that wing roots generate the bulk of the lift on small, tapered flying wings.
     
  20. May 14, 2017 #20

    plncraze

    plncraze

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    Marske used very tapered wings for the same reason as listed above. He was not concerned about bad stall characteristics because the elevators in the wing root area would loose effectiveness before the tips would stall.
     

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