Flying wing for high efficiency

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by karoliina.t.salminen, Jun 14, 2011.

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  1. Sep 9, 2012 #161

    Aircar

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    Keep at it -- the vortex lift tests with the oscillating flap looks most immediately promising to me and seemingly easy to test cheaply on a car mounted rig --and any side effects like noise or flutter can be assessed early on. Keep us posted if you can please.

    BTW - I can't help but notice that I now have the "Royal Flush" on this part of HBA - six in a row !! Do I get a gold star or something ? (or should I get a life instead - or some more sleep even -hmmm, internet addiction ..? :ponder:
     
  2. Sep 9, 2012 #162

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  3. Sep 11, 2012 #163

    Aircar

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    Many thanks for the video Henryk -- the frequency of the oscillation is in the hundreds of cps range and clearly audible so raises questions about acceptability for use in manned aircraft --it may be possible to suppress noise or by anti noise and the actuation system would be needing careful design for reliability and fatigue (exactly how the flap is stopped and reacclerated each time is not obvious -- some aerodynamic 'rebound' seems likely although the other video on it (not in a wind tunnel) refutes the possibility of any flutter or self excited flow mechanism --the 'fan' effect apparent from the tufts is also clear so speeding up of the air is involved as well as greater deflection --in that case the comparison to slipstream deflection by a propeller needs to be made (the oscillating flap would seem to keep the air closest to the wing surface but can it also give enough thrust for flight ? I had presumed that the slat would be stopped for cruise and thrust provided by a propeller or jet --also the slat could be used for control I suppose. (when moving and when stopped even ?) This is definitely something worth further research .
     
  4. Sep 11, 2012 #164

    topspeed100

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    Isn't that then the Synergy ?

    I have been studying two concepts for HPA/solar powered hybrid and I am inclined to think "normal" wing in lifting body with tails...featured more less into manta ray direction might be effective. I hate the low cl wings on flying wings that we have seen so far. I assume the electric power will make the more efficient plane possible just because the weight distribution can be handled differently due to the free placing of the accus/batteries.
     
  5. Sep 11, 2012 #165

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    Topspeed - I had presumed you were off 'pumping iron' to get those biceps in shape for some aerial 'thrust augmentation' --and don't forget that we ARE taking swabs for drug use after the flight ....

    I just came across a reference to the Icarus cup in some magazine --apparently it is about reviving the idea of human powered or power assisted aircraft and came about after someone thought of the man powered aircraft in connection with the recent London Olympics (and the eccentric English did revive the whole man powered aircraft thing with the Kremer prize and most of the attempts through the sixties and seventies ) Must look for a link .

    What # posting by Orion did you refer to ? must have been a fair way back .

    And aren't we banned from mentioning the Syner ...thing ? ;) ("open thermodynamic systems" and free energy are in fact banned topics on some journals along with cold fusion )- a recent book launch "Physics on the fringe' by Margaret Wertheim, might appeal to you and the organization for those whose ideas are deemed heretical or unscientific - 'peer rejected' in effect - is covered in it also ; the title is like "Natural Sciences Association' NSA

    You cannot have a very high Cl on your MPA to avoid excessive induced power -the minimum power speed Clcubed/CLsquared max sets the wing area if you just want to stay in the air at least power (the HIGH Cl Kasperwing -tailless design is probably not suitable on that basis but even then there is a controversy over the airfoil Cl/Cd at high Cls with detached vortex flow '"flying wing for high efficiency" can mean high possible CL for landing (without much concern for lowest drag) and therefore minimum sized wing that then gives high maximum speed - with everything retracted (Karoliina's objective I think ) but poor mid range performance . Trim drag does not need to be high for a tailless aircraft in cruise as you seem to imply.
     
  6. Sep 11, 2012 #166

    Aircar

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    Topspeed, - fellow man powered enthusiasts apparently had their inaugral meeting in July --the Icarus cup Royal Aeronautical Society | Event | Icarus Cup for Human Powered Aircraft (rules allow up to three seats ....)

    And the off mainstream physics community - www.worldnpa.org or the

    enwikipedia.org --they have had to exclude some of the more outlandish of the 'fringe' and the article I saw specifically listed 'open thermodynamic systems' -purporting to extract free energy from somewhere, as excluded.
     
  7. Sep 11, 2012 #167

    Norman

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    That phrase "extract free energy from somewhere" is to limiting. A Stirling engine is physically closed but open to the flow of energy. That energy often comes from a waste supply from some other system and therefore can be called "free energy from somewhere". I remember one design of night vision goggles that used a small Stirling cycle engine running on heat of the solder's forehead to pump coolant through the photomultiplier. This wasn't fringe it was a creative use of what is otherwise just a toy to do useful work
     
  8. Sep 12, 2012 #168

    Aircar

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    G'day Norman - your example is a closed system if you stick said soldier in an insulated box and prevent any flow into or out of the system -- it will require a sink somewhere to maintain the temperature drop needed so to that extent is open . Some of the more way out ideas involve extracting the zero point energy and 'stealing' energy from other dimensions as the less bizarre ideas.

    We have had claims of zero drag bodies,'self propelling' (in the literal sense), non increasing drag with speed and 'open thermodynamic system' mysterious and miraculous aerodynamic acheivements being claimed (and send money to PO Box .... after a while )

    I attended the Australian launch of the book by Margaret Wertheim and spoke to her about some aspects of the psychology behind such proponents (her book is more about the milleu of the field and the psychology of the adherents rather than the physics as such. The esoteric nature of fundamental physics makes telling the BS from the plausible but mind bending too hard for anyone but the deeply immersed and experienced in the field . Making up terminology to confuse the issue and being unable to explain their great insights to the plebs in any intelligible fashion is part of the genre and what are ostensibly earth shattering breakthroughs never seem to work 'as advertised' -- the ratio of charlatans to the deluded or just baffled onlookers is very high but the demand for ever more arcane theories is insatiable (and the 'emperor's clothes' technique is used to shup up dissidents --or to appeal to the right of speech free of questioning or adopting the mantle of misunderstood visionary or wounded heretic --whichever works to avoid scrutiny and justify collecting money for promises.

    It turned out that even the 'outsiders' who set up their own organization had to censure and even ex communicate those of their own who started to embarrass the less radical elements -- ie even the peer rejected amateur physicists got rejected ... Freeman Dyson wrote a very interesting foreword and book review --and mentioned his contact with several maverick scientists (he himself is a highly respected but also dissident scientist when it comes to the climate change issue as one example --the pressure to conform to a consensus is a powerful force against new ideas or contesting claims and he pin points the problem of sorting out the physically wrong from the observable and provable by test .

    At the nearby university lecture (monday night) on the 'century of observations on the red shift' and galaxy structure etc someone asked how we can measure red shifts of whole galaxies at 95% of the speed of light and the principle that the amount of energy needed to get that close to the speed of light become nearly infinite -- the answer is that "the speed of light is a local phenomenon and it is the expansion of space ,"nothing" that is carrying the galaxies apart without there being any relative velocity --the usual 'explanation' without anything explaining where all this extra space comes from (and maybe even spacetime ) --the squashing of all the mass of the universe into a single atom is hard enough to swallow but that volume is but a microscopic amount compared to the space between the specks of mass . How anything 'makes sense' in this field is beyond me but fascinating to ponder (the book "Great Mambo chicken and the transhuman condition' subtitled "science slightly over the edge" is another looking at the sort of people and things 'pushing the envelope' of technology and believability --it is a great read and plenty of laughs --one chapter deals with Bob Truax and his rocketry work -- I was stunned to read that Evel Knievel conceived his famous rocket bike canyon jump (using Truax's rocket design) in,-- Kalispell, Montana . (in the bar of "Moose's Place ...) what do they drink there ?


    On this forum we have been exposed to some non -mainstream aerodynamic type claims --the Synergy is the best known and the oscillating vortex lift principle from Henryk is another --contentious, different in details and basis but also responded to differently and in any case moving towards the proof stage before too much longer. (homebuilding itself is split between the conventional even traditional and the leading edge stuff so the reaction to unconventional design is just as polarized . The flying wing adherents and those who are non believers (or rather trusters in their own case) is a good example on a more nuts and bolts level --and the flying car an even more stark divide .

    I think we also see aspects of the psychological motivations in this field similar to the fringes of physical science (and the borderlines of hard enginering versus intuition --the case of Isaac Newton as alchemist,occultist, biblical fanatic and also great scientist is probably a good example. Light Aircraft design might have reached a plateau of possible performance (even close to the top by the thirties based on the comparison between say the Me 108 and Today's equivalent --or the Bonanza v Cirrus ) and innovation has not been conspicuously successful in the market yet we still plug away on new designs. How much of this activity is strictly logical?
     
  9. Sep 12, 2012 #169

    Norman

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    Well, yes, if you take the external source and sink away from an open system then it's a closed system. An external source is what makes a system open. Just as the Earth is an open system that draws energy from the sun, uses it while it's here, and then releases it into space. I'm not really interested in disusing this stuff and I'm very disappointed in what this thread has degraded into. Topspeed has been on my ignore list since shortly after he joined because of his nonsense and you may follow soon. Not that your posts are nonsense but you're very verbose, tend to go off on tangents (interesting though they may be) and seem to actually enjoy arguing with crackpots. Your youthful exuberance is exhausting! I'm unsubscribing from this thread
     
  10. Sep 12, 2012 #170

    Aircar

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    I didn't set out to annoy you Norman --the thread is indeed a long way from "flying wing for high efficiency ' (and respecting your expertise in flying wing design I can see the reason for feeling that it is off topic --but so is the stirling engine on a nose - I don't find that irritating but interesting) Tease apart the topic a bit though and maybe the discussion is not so far off track after all -- What is MEANT by "high efficiency" in this context ?

    If I recall correctly the starting point was wanting to cruise for extremely long distances across featureless and hostile oceans like the North atlantic -- given that efficiency has a meaning of gaining an output of some kind for the minimum input then isn't it fair to ask WHAT is the output we are going to measure ? (and next the INPUTS)

    If the object is to convey a human being from Europe to America then we have various ways of doing that available --mainly by commercial airliner but also ship (you COULD even row a small boat as has been done or sail ) -the known cost of the airline ticket is FAR below the best possible fuel only cost for a small personal aircraft of one to four seats , the time SAVED by flying at 600MPH and 30 000 ft has also some value --and you do not need to buy the aircraft or invest in the flying training to use it -nor pay any other taxes or costs like landing fees ATC, search and rescue ,emergency gear etc etc
    (and any real EFFICIENCY analysis will take account of headwinds which might be one third of the small aircraft's cruising speed but even assist the stratospheric jet by jetstream ) -- the RELATIVE diseconomy of travel of this kind by small aircraft is SO bad that there is no rational or EFFICIENCY based reason for even thinking of doing it --by flying wing or anything else . (this is far more practical stuff than theorizing about open thermodynamic systems or multiverses with energy connections to ours -the zero point thing (mentioned by Burt Rutan at his Oshkosh lecture so maybe not so unacceptable on a forum like this --the 'finding' that an unseen,undetectable 'stuff' called Dark Matter and the equally nebulous (pun) "Dark Energy" makes up OVER 95% of the ACTUAL Universe might be of some interest to even a 'practical' engineer .

    Why would anybody immerse themselves in the considerable task (monumental more like) of conceiving designing and building a specific intercontinental aircraft when the most simple analysis shows that it is the most IN efficient way to do the task ? -we don't argue over the best type of stone axe to make but this BASIC proposition is little different . Like as not the aircraft will only be used for the ONE or a handful of such marathon tasks at best --amortizing the cost of the aircraft in dollars and manhours over those few flights takes the relative cost of the airline ticket versus handmade long range homebuilt to the hundreds to one range .

    If there is no RATIONAL reason for undertaking the whole exercise or continuing to discuss it then what is the reason ? Maybe re thinking the raison de etre' is NOT somehow ridiculous . Topspeed seems to have placed a higher value in his version of "EFFICIENCY" on saving out of pocket expenses by using solar energy and human power --to that extent the basic thinking is understandable --it is not ludicrous in principle (others with some sort of fixation on personal abuse or some abstract goal HAVE rowed across the Atlantic --they expended nothing in fuel in one sense and didn't cost in their time at all --a different view of what constitutes efficiency by reducing the INPUTS and valuing them differently )

    You can be sure though that the mention of the words "flying car" or suburban flight,air commutting etc will attract a barrage of dismissive put down or avuncular advice that it is ridiculous --and no one will likely demure or defend the notion (even when the EFFICIENCY in this case involves the saving of millions of lost productive man hours in a real economic environment --a real measurable and useful output that compares more than well with the existing alternatives . If someone posts "need help with making dummy machine guns for my Sopwith Pup" there will be no lecture about how stupid the idea is or worthless,not as good as ( ) or doomed to fail, not worthy of being entertained etc etc. My point was simply to be honest about technical enthusiasms that might in fact have no real engineering justification --and not to pretend otherwise , if I boiled it down. I tried to inject a little humour with Topspeed's man power high altitude flight musings and didn't get offended by them in the least --if a picture can be worth a thousand words then that little video clip saved you much reading as well:)
     
  11. Sep 12, 2012 #171

    topspeed100

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    Norman I did start a thread of her own for the solar/HPA powered kite. I understand 100% your aggrivation of my input in this spesific thread. This is not about high AR plane with non fossil fuel...I am sorry for ruining your day sir ( it was not the intention ) !

    Aircar and Norman..I am not under any drugs. I might get some endorfins every now and then for playing frisbee golf and cycling, but that is all.
     
  12. Sep 13, 2012 #172

    Aircar

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  13. Apr 29, 2013 #173

    Norman

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    The X48c made its final flight a few days ago. This was contract work for Boeing so it's not certain if there will be publicly available reports with professional analysis but some of the raw data may be available in a year or two.
    [video=youtube_share;Em8WzIcDiCs]http://youtu.be/Em8WzIcDiCs[/video]
     
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  14. Apr 29, 2013 #174

    Norman

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    Geez that was harsh. Who was that cranky old geezer?
     
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  15. Apr 30, 2013 #175

    BBerson

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    I miss Aircar ( the sensible, verbose tangents)

    But my free time is not infinite, one post per day would be nice, I think.
     
  16. Apr 30, 2013 #176

    Aircar

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    Hmmm.... missed am I? having suffered complete disconnection from the cyberverse thanks to my intransigent telco my 'verbose and sometimes interesting' rants have of neccesity been curtailed. Maybe it is karma. To split some more hairs (Norman) I wonder whether we can really include the blended wing body with huge beavertail elevator and dual fin/rudders as a 'flying wing' -- that should start another debate if nothing else.
     
  17. Apr 30, 2013 #177

    John Newton

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    Why did they get rid of the winglets on the BWB and move back to conventional fins, I've often wondered but couldn't see a reason stated in the literature I have read, noise reduction? handling? effieciency? Not sure.
     
  18. Apr 30, 2013 #178

    Norman

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    A little bit. Surprised?

    That sucks! Hope you can get whatever kinks there are in the system hammered out. You're a fascinating person and share a lot of good and hard to find information. My soggy little brain just has a hard time keeping up with your exuberant writing style.

    It's always interesting. I just find it hard to stay on topic when you go off on a tangent. I have a case of ADHD from hell and some injuries have rendered my right hand useless so writing is a bit of a chore

    I don't believe in karma. Nobody gets what they deserve out of life. It's a stream of random crap, if you're lucky you get a little more than you worked for, if not, it can be really disappointing.

    Although you may have heard otherwise I'm not devoted to any particular school of thought on this. In fact I was actually called a heretic once although I consider myself a philistine. The most common definition of a flying wing, a wing that does not rely on an auxiliary wing for pitch trim, allows vertical fins and even a fuselage but not a horizontal tail or canard. At the opposite end of the spectrum you have the Only the Wing crowd who believe that any vertical surface, even the sides of a cockpit bubble, is anathema. In my little camp wetted aspect ratio rules but makes allowances for practicality because you just can't squeeze two people and an engine into an efficient wing. Vertical fins are acceptable but they should be no larger than absolutely necessary and not detract from the function of the wing
     
  19. Apr 30, 2013 #179

    clanon

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    "Try to go Zen , young Padawan"

    PS: In other words what goes around comes around ; nothing can escape the second Law of Thermodynamics.

    (in a closed system like this one ,anyway)
     
  20. May 1, 2013 #180

    Aircar

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    Nice thoughts Norman ( I hope your particular circumstances are trending upward deserved or not -I've had my share of 'misfortune' as well so concurr with your heretrical phillistinism. ) and Clanon I DO hope you have excluded Mr Mc Ginnis from the inexorability of the second law of thermodynamics ;) --the latest Australian Popular Mechanics features the Synergy on the cover and relates how John had an 'epiphany' after scouring the web and coming across Greene's paper --no longer will drag increase as the square of speed for him ... I was a little tongue in cheek regarding the 'pure' definition of a flying wing (or the somewhat similar 'tailless aircraft' --this definitional dispute is matched in the flying car world with those who go for 'flying car' vs the 'roadable aircraft' --I like "flyable vehicle" actually --when on the ground a "flying car" cannot be ['flying' that is ;- ditto for a 'flying wing' ] The deletion of a tailcone and isolated tail is of some considerable import to a flyable vehicle actually and tailless types are quite common in this area . High efficiency is but one reason for considering a 'tailess' /flying wing config. - it might be that some other factor like say gaseous or low temp fuel storage favours the blended wing body type --I'd like to see it actually.
     

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