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Isnt this a sexy plane?

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by berridos, Dec 13, 2019.

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  1. Dec 14, 2019 #21

    Sockmonkey

    Sockmonkey

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    I was under the impression that most people just aren't good at explaining complicated things to the average person.
     
  2. Dec 14, 2019 #22

    Mad MAC

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    As for the orginal question regarding the fence position, one could possibly conclude that the end plates drive the initial stall location inboard (at the wing tip it behaves somewhere between an aft and forward swept wing) and they might actually be to slow the stalls progression outboard.
     
  3. Dec 14, 2019 #23

    berridos

    berridos

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    Horten wings are similar to deltas? I read the swirl location in fighter jets determined the stall behaviour. Thats why they use double deltas to control the swirl location in low speed maneuvers.
     
  4. Dec 14, 2019 #24

    Aesquire

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    The tip vertical stabilizer/drag rudders are a well proven way to help keep the pointy end in front and increase wing area available for roll & pitch control.

    Compare to the Northrop line of flying wings up through the B-2 Spirit.

    The Northrop clamshell drag "rudders" are at the wing tip to get maximum leverage to control yaw. A well designed swept wing has a lot of yaw stability, but adverse yaw from roll inputs calls for some kind of yaw control. The long wing Horten designs accomplish that progress has effect, but it costs in structural weight, hanger space, and drag.

    And the wing tips also are where you get the greatest leverage for roll, and in a swept wing, pitch. It's a competition for best "real estate" on a wing.

    Thus moving the yaw control surfaces out of the way of the pitch & roll surfaces should improve handling & drag. Even if you aren't getting optimized vortex use.


    The high aspect ratio wings on a sailplane still have the reduction in lift and increase in drag from the tip vortex as a Cub or Mustang, but the high aspect ratio reduces the percentage of wing affected. Not the effect completely.

    A flying wing, especially a swept wing, has that effect right where you want your roll & pitch leverage.

    it's a lovely plane. Looks like a Velocity that got a fortuitous copying error. ;)

    Please make a kit!
     
  5. Dec 14, 2019 #25

    Johan Fleischer

    Johan Fleischer

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    2.jpg [QUOTE="And yes, it's a sexy danged airplane. ;)[/QUOTE]
    Horten Aircraft hopes to make a 4-seat version also. It could be even more sexy :) Maybe it could look a bit like my own sexy dream, here: (not finished yet, I yet have to model View attachment 91223 position lights, antennas etc.)
     
  6. Dec 15, 2019 #26

    Doggzilla

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    Unfortunately its willing arrogance.

    Go try and clarify any scientific topic on Wikipedia and it almost always results in an argument because certain members demand that their over complicated explanations be the current revision.
     
  7. Dec 15, 2019 #27

    gtae07

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    Sounds like almost every book I've ever tried to read regarding structural analysis. Lots of derivation, no real-world relations.

    The problem is that serious texts are almost universally written in a deductive style. And that's a great (and natural) way to present something when you already know the material. The problem is, humans naturally learn about the world inductively and a sizeable chunk (dare I say, a majority) of the population prefers to learn that way in academic settings, too.

    I loved my high school physics teacher because he taught inductively. We started with very simple everyday stuff and figured out equations for things like time vs. distance at constant speeds. Then we built on all those things to get to the complicated stuff. Unfortunately, almost all of my engineering classes in college went the other way--they pounded derivations and first principles into your head with lots of big, nasty equations and little to no real-world relation.

    I've long dreamed of a "structural analysis for real people" book, written in plain English, with real-world examples you can replicate. For example, stack a few thin strips of wood together and bend them as a beam to demonstrate compression, tension, and shear. Then, show each equation and how it relates to the stacked wood. And so on. Not "consider arbitrary body B with generalized forces R, S, and T..." and lots of "it can be shown that...". In my headier days I thought about writing it.

    It's less explicit focus on verbosity, and more focus on "rigor" and formality and the unwritten style of academic papers. If anything, they're space-limited so they need to pack as much into the space as possible--hence lots of big words and dense writing.

    I'd say that's a side effect of a very utilitarian company culture. I think where those companies--and especially SpaceX--have really stood out has been in the "hardware-rich" development process that Western aerospace has generally gotten away from. Risk tolerance in the industry has gone way down--and I'm not talking about life and safety risk, but risk in the financial, program, technical, and PR sense. Failure--any failure, even of prototypes where nobody's at risk--is unacceptable; shareholders don't like RUDs, government doesn't like them, and the general public is horrified and cheerfully entertained at the same time. The attitude has thus become "you'd better get it right the first time, because that thing's expensive"... and because everyone's trying to get it right the first time, it's expensive.

    SpaceX succeeded in economically recovering and reusing boosters because it was willing to blow up a few rockets along the way, until things got figured out. Traditional aerospace would spend 10 times the money on design and manufacturing (and paperwork, and audits, and component testing, and analysis, and more analysis, and inspection, and....) because they can't afford to lose the thing they're spending billions to make.

    Chinese aerospace (especially fighter development) seems to take to that lesson as well. The US expects/demands that the first airframes be as close to finished designs as we can get them and starts serial production early in the test phase. China, meanwhile, builds a prototype or two, flies them, builds another couple with tweaks and changes, flies that, tweaks some more and builds a few more, flies those... and while they may have run through several generations before their fully-capable airplane is ready to go, they've been learning along the way. Of course, they don't have shareholders and congresscritters to appease...

    And whoops, way off-topic now...


    Back on topic, yes indeed, it's a pretty airplane. Looks like the guy's trying to fly it from the back seat, though. And what a huge glareshield! It's even bigger than the dash on a hybrid car...
     
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  8. Dec 15, 2019 #28

    Aesquire

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    progress has effect,.... i meant proverse yaw

    autocorrect. and hasty proof reading. iirc you collide with Mars for that last sin
     
  9. Dec 15, 2019 #29

    autopilot

    autopilot

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    It is really nice, pity about the visibility. It,s almost like they designed the wing and then fit the pilot where he wouldn't effect the balance.
     
  10. Dec 15, 2019 #30

    Aerowerx

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    Exactly!

    I have been trying to advocate this for several years! It puts to rest one of the complaints about tailless aircraft.
     
  11. Dec 15, 2019 #31

    Aesquire

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    It's a good idea on any light plane to put the variable pilot mass at the C.G.

    The trouble is the tendency for wing spar to be close to that locatuon, too. If you want to sit on top of it, the wing blocks downward vision.

    On a pusher, especially a flying wing, I like planes that have Windows in the leading edge and floor. A scale B-35 cockpit would be great.

    Johan's lovely wing above looks reasonable for visibility. Better than many light tractor normal planes.

    The Horton here looks like a fairly blocked down view.

    If ground visibility is your mission, you probably want a high wing, and other features. Search & rescue, etc.

    In WW1, the German Army adopted the Fokker D VIII "Flying Razor" parasol wing monoplane fighter. It won over an arguably more advanced mid wing prototype, because the Army thought it important to be able to look straight down. For a observation plane that's vital. On a fighter? Not so you'd notice since WW2.

    I question how important straight down vision is to flying? How important is it to you?
     
  12. Dec 15, 2019 #32

    aeromomentum

    aeromomentum

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    Do not think of it as "wing tip" vortexes. This is incorrect thinking and will lead to incorrect solutions. In reality it is finite wing trailing edge vorticity. In general the center of the energy is not at the tips but about 2/3 of the way from the center to the tips. There is vorticity starting with zero at the aircraft center line and growing as you go outboard.
    Many people have heard of the NASA study that showed winglets could reduce induced drag. Few have heard of the follow on sturdy that determined the best angle. That study showed horizontal was optimum. In other words longer wings have less induced drag. But this is obvious using Newton's laws. F=M*a, v=a*t and KE=1/2*M*v^2. There is no way to cheat physics. People that say they can are cheating you. This is also called marketing.
    Of course there is some synergy by using winglets for vertical stabs but this normally more than offset by other factors.
     
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  13. Dec 15, 2019 #33

    berridos

    berridos

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    Would those fences at two thirds of the span also make sense on a delta?
     
  14. Dec 15, 2019 #34

    Hot Wings

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    Lots to this. Such a book would probably sell well - IMHO
    The Circuits text I have on the shelf starts out in the first paragraph defining voltage as a differential and then moves on to Coulombs etc.
    Lots of people would learn much faster if the concepts were presented as a bunch of penguins on a water slide and how fast the pool at the bottom fills up and how far they slide relative to their launch height. It is all the same math.

    What this leads to is situations like the fill in teacher we had a few years ago at the local college. He had a fresh doctorate and knew his math. If I needed a widget analyzed he might get the job. If I needed a widget designed and developed he would still be looking for a job. His students didn't get their money's worth the year he was there.

    That is one of the things I like about this group. We get/give a fairly balanced way of discussing the concepts, both mathematically and by example.
     

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  15. Dec 15, 2019 #35

    Dillpickle

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  16. Dec 15, 2019 #36

    Vigilant1

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    All true. I have two more modest requests:
    1) A glossary in the book for every term, constant, labelled variable, etc in the book. Give me the name, definition, and what page it is first discussed/derived/used in this textbook.
    2) Include a tangible example for every formula and concept in the book. And, if it isn't too much trouble, include brief examples that tie newly introduced concepts to the real world. The folks reading these texts are hoping to be engineers in the physical world, not theoretical physicists.
     
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  17. Dec 15, 2019 #37

    BJC

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    I was sitting in the office of the Chairman of the Physics Department at Georgia Tech, petitioning for credit for a Sophomore Physics course. After an extensive technical interview, the Chairman asked, “What do you think about the text book?” I told him that I thought that it was poorly written; the author’s way of explaining things was overly complex, and, at times, confusing.

    He slapped the desk, and shouted, “Yes, that is exactly what I told him when I reviewed the draft book for him.” It turned out that they we good friends. I got the credit.


    BJC
     
  18. Dec 15, 2019 #38

    Topaz

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    By way of committing reasonableness and getting back on-topic, yes, the downward visibility of this new Horten design is gong to be a bit of a challenge.

    Then again, a lot of "cruising" cross-country airplanes "suffer" from some form of this. Small windows, especially for pressurized models, poor over-nose view angles, etc. For some kinds of flying, seeing horizontally (traffic avoidance) and only having enough downward visibility to safely land is "good enough." And you can always bank the airplane if you need to see "down" more.

    Flying wings (tailless aircraft in general) have a really tough time with cockpit and cockpit-area design. Especially for swept-wing designs like this one, it's tough. Because of the limited pitch authority inherent to discarding the tail, a narrow CG range means all the variable-load items (occupants, fuel, baggage) need to be as close to the CG as possible, and then the wing spar always seems to want to go right through the people.

    For the kind of airplane this seems to be, I wouldn't worry terribly about downward visibility. And I'm impressed by the fact that they were able to package two people side-by-side in a small swept flying wing.
     
  19. Dec 15, 2019 #39

    Hephaestus

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    A 20$ ebay/amazon backup camera can solve a lot of downward visibility issues...
     
  20. Dec 15, 2019 #40

    BJC

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    I keep reading that. Have you flown with one? Does it really work well?


    BJC
     

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