Shoulder wing unpopularity

Discussion in 'Hangar Flying' started by stanislavz, Nov 9, 2019.

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  1. Nov 17, 2019 #121

    Tom Nalevanko

    Tom Nalevanko

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    There was a very interesting geodesic structure, mid-wing design by Harry Thalman. The Thalman T-4 was ahead of its time and performed better than the Cessna and Piper of its class. I have extensive documentation on it but unfortunately on another computer. Unfortunately Mr. Thalman flew into a snow bank and did not survive. And that was effectively the end of the design.. Google around for better pix.

    4B7C6A56-0B72-4FBD-B7E1-38610BFB83F4.png

    Here’s a quick Google result.

    Best,

    Tom
     
  2. Nov 18, 2019 #122

    FritzW

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    That looks vaguely familiar...

    Flat wrap RL Mock Up.jpg

    Mine ended up with a bubble canopy and a Lysander style wing to solve the CG issue.
    Router Lark Cutaway 7.jpg
     
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  3. Nov 18, 2019 #123

    poormansairforce

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    Thats the 6 pack....err..keg version!:beer:
     
    Last edited: Nov 18, 2019
  4. Nov 18, 2019 #124

    Aerowerx

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    Do you have any idea how that shape affects the drag?
     
  5. Nov 18, 2019 #125

    Vigilant1

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    It must just be that photo, but the plane looks nose heavy.
     
  6. Nov 18, 2019 #126

    Riggerrob

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    No
    No, the Thalman mid-wing was not nose-heavy. It just had a bubble canopy that extended all the way to the propeller. Try to think of it as a Sonex with an even longer windshield.
    Thalami was following 1930s logic that believed that the sleekest (lowest drag) fuselage was a revolved body based on a known airfoil section. Since then we have learned a lot about streamlining wing roots.
     
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  7. Nov 18, 2019 #127

    stanislavz

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    Looks like "Noosphere" https://en.wikipedia.org/wiki/Noosphere is totally working :)

    Back to topic - Lysander (double tapered ?) wing, can be made symetrical - widest span at the middle of wing at strut attaching point ? Just how to make both parts join point nice to airflow.. (loud thinking, of how you can make it nice in one mold)

    Have you found any more info, on how it helps with inter reference drag ? Some low power/high performance had this kind of fuselage/wing join

    [​IMG]

    Morning coffee is working.

    Double tapered aka Lysander wing can be made using two half span mold with two type of closing ribs for required angle..
     
    Last edited: Nov 18, 2019
  8. Nov 18, 2019 #128

    berniematic

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    [​IMG]


    Don't know if its been mentioned but they've been there and done that -
    Bolkow Aircraft

    Also cygnet homebuilt (vikingaircraft.com)
     
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  9. Nov 18, 2019 #129

    BBerson

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    What is that neat C-4 airplane? Looks like a Dehavilland DH-53 without struts.
     
  10. Nov 18, 2019 #130

    stanislavz

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    "Буревестник" pre 2ww soviet buil high performance airplane. Info only in Russian. Wood only. Will add more info on structure later


    http://www.airwar.ru/enc/law1/s4burevestnik.html
     
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  11. Nov 18, 2019 #131

    FritzW

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    If you squint you can see how you could make a Lysander'ish wing with two straight spars. I don't know about mold's, I'd just make it a regular built up wing. The root rib would already have a short chord so there would be no need for a Zenith 701/750 or Fi-156 "cuff" at the root.

    Westland_Lysander-3-view.jpg
     
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  12. Nov 18, 2019 #132

    stanislavz

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    Roger. I can see it. Just - is it worth it ? Normal tapered wing - will need two different sets of molds. Or high quality craftmanship if done in wood.

    Composite - i doubt, but one mold for both parts. And it will kind of on high end side of builds.

    Plus nicer to un-tapered swept forward.

    How digged this compound tapered wing topic more ? Stall characteristic ? Interreference drag with fuselage ?

    From mine gut feeling - it loks like combination of two tapered wing, combined at fuselage - ie minium flushing via fuselage. And minimum end vorticles. Plus sound structure if strut braced..
     
  13. Nov 18, 2019 #133

    cluttonfred

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    stanislavz, I like the concept a lot but personally I would like to see some simplification for an easier build. I would use straight lines on the fuselage (top longeron, bottom longeron (two sections)). Since you're putting a fairing on the wing center section, why not put the wing on top of the fuselage and use the fairing to cover it for easy assembly/disassembly and inspection. The horizontal fuselage end would work well for an "H-tail" (twin rudders) or you could carry to a knife edge and use all-moving and possibly identical vertical and horizontal stabilizers and a short stub rudder like the Boulton Paul Phoenix. See https://www.homebuiltairplanes.com/forums/threads/midwing-musings.28651/page-3#post-406693

     
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  14. Nov 18, 2019 #134

    stanislavz

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    Hi. You are taking about volksplane, but with shoulder wing-spar to the back of seat ?

    As Wittmann proved you not have to round edges to go fast. And you do not have to scraf join plywood. And - you do not have to put plywood at 45 degree for wing torsional strenght.

    But - he showed us, how you can use best available tech of the day...

    So - i would be still up to foil covered foam female mold with no-sanding/minum sanding for fuselage and wings. Cheap fiberglass with pvc foam / cheap carbon fiber without foam for panels and extruded carbon rod where necessary - for stable and predicted result.

    And i do not believe, that cheap homebuild in materials and man hour total, should be ugly :) lets do it smart...
     
  15. Nov 18, 2019 #135

    BJC

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  16. Nov 18, 2019 #136

    stanislavz

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    And one question - how much taper can be used in compound tapered wing without using V struts ? I do not see it very torsional rigid with 50 % taper..
     
  17. Nov 18, 2019 #137

    cluttonfred

    cluttonfred

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    Not quite that simple, but I am flattered by the comparison. I *like* Volksplanes! ;-)
    Yes, that's the sort of wing position/canopy fairing I had in mind.
     
    Last edited: Nov 18, 2019
  18. Nov 18, 2019 #138

    Speedboat100

    Speedboat100

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    I tought this was about shoulder wing designs.
     
  19. Nov 18, 2019 #139

    Himat

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    Why shoulder wing designs are «unpopular»?

    Or why are shoulder wing designs rather less common than high and low wing light airplanes?

    It is down to packaging, structure, weight and balance. In a light airplane the largest part of the load is the pilot and passengers. This load differs a lot depending on the actual persons. The easiest way to accommodate both a light and heavy load without a large shift in airplane CG is to place the load at the design CG.

    Now, in an orthodox design with wing first and tail aft the wing spar is usually at where the CG resides too. Least frontal area and simple construction is to have a low wing with the passenger siting on or straight above the spar. Make the wing strutted and the carry through structure for a high wing is reasonable light and easy to design.

    Shoulder wing gets more complicated, expensive and or heavy. My take is then that most airplane designs are specification driven and the virtues of a shoulder wing airplane do make it the chosen configuration that often.
     
    Last edited: Nov 18, 2019
  20. Nov 18, 2019 #140

    BJC

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