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#1
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Do winglets produce thrust?
Anyone?
Bob |
#2
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"Bob Salvo" wrote in message ... Anyone? Bob That's against the laws of thermodynamics. If you can make a passive device produce thrust you should rule the world with your new perpetual motion machine! At best it reduces losses. Keith |
#3
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Keith W wrote:
"Bob Salvo" wrote in message ... Anyone? Bob That's against the laws of thermodynamics. If you can make a passive device produce thrust you should rule the world with your new perpetual motion machine! At best it reduces losses. In my country, our gliders move forward because the wing produces thrust, and our sailboats move over the water because the sail produces thrust. Whether we should rule the world is causing much controversy. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA |
#4
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Don't think so.
Gravity provides the thrust. Quite noticeably when fuselage is pointed vertically. None at all when fuselage/wing is horizontal. In article , Eric Greenwell wrote: Keith W wrote: "Bob Salvo" wrote in message ... Anyone? Bob That's against the laws of thermodynamics. If you can make a passive device produce thrust you should rule the world with your new perpetual motion machine! At best it reduces losses. In my country, our gliders move forward because the wing produces thrust, and our sailboats move over the water because the sail produces thrust. Whether we should rule the world is causing much controversy. |
#5
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"Eric Greenwell" wrote in message ... Keith W wrote: "Bob Salvo" wrote in message ... Anyone? Bob That's against the laws of thermodynamics. If you can make a passive device produce thrust you should rule the world with your new perpetual motion machine! At best it reduces losses. In my country, our gliders move forward because the wing produces thrust, and our sailboats move over the water because the sail produces thrust. Whether we should rule the world is causing much controversy. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA Yep - I was thinking of thrust as a primary force rather than that due to 'tobogganing' (ie a change of supporting force forward of the vertical). Away I go to the sackcloth and ashes 8-). As to whether the US should rule the world - I will duck out of that to prevent a repetition of the reams of vehement verbiage which has already filled the bit stream 8-)) Keith |
#6
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I don't think it was that "US" rules the world.. but more the line that.. he
who masters the air above us.. (glider pilots) .. rule the world.. BT "Keith W" wrote in message ... "Eric Greenwell" wrote in message ... Keith W wrote: "Bob Salvo" wrote in message ... Anyone? Bob That's against the laws of thermodynamics. If you can make a passive device produce thrust you should rule the world with your new perpetual motion machine! At best it reduces losses. In my country, our gliders move forward because the wing produces thrust, and our sailboats move over the water because the sail produces thrust. Whether we should rule the world is causing much controversy. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA Yep - I was thinking of thrust as a primary force rather than that due to 'tobogganing' (ie a change of supporting force forward of the vertical). Away I go to the sackcloth and ashes 8-). As to whether the US should rule the world - I will duck out of that to prevent a repetition of the reams of vehement verbiage which has already filled the bit stream 8-)) Keith |
#7
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Winglets produce lift, with a vector. The vector direction
can be perpendicular to the winglet surface, fwd or aft. That is dependant on how it is shaped and mounted. A lift vector facing the nose (fwd) being called thrust might be a mishmash of terms, but it happens. I usually think of thrust as a motive force acting on the vehicle. Winglet vectors are recovery of lost energy by reshaping flow to our advantage. Good idea, yes, thrust...... probably not a really good description of what is happening........ Scott. |
#8
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Bob Salvo wrote:
Anyone? Bob Yes -- Denis Private replies: remove "moncourrielest" from my e-mail address Pour me répondre utiliser l'adresse courriel figurant après moncourrielest" dans mon adresse courriel... |
#9
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Keith W wrote:
That's against the laws of thermodynamics. No. Provided the thrust of the winglets is not higher than the drag of the other part of the glider, that's not (and of course the winglet thrust is only a few % of the glider drag) -- Denis Private replies: remove "moncourrielest" from my e-mail address Pour me répondre utiliser l'adresse courriel figurant après moncourrielest" dans mon adresse courriel... |
#10
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Not thrust in the same way as a propulsion system,
but winglets generally do produce a lift vector that has a spanwise and a chordwise component. Since the flowfield at the wingtip is angled inward, the winglet has an incidence angle that is slightly outward-facing -- while still producing a positive angle of attack (look at your winglets from straight ahead to see that this is true). This means that the 'lift' produced by the winglet is directed mostly inwards towards the fuselage, but also forwards. I don't know what lift coefficients winglets fly at, but I suspect the actual magnitude of the 'thrust' is very small. 9B At 19:54 28 November 2003, Bob Salvo wrote: Anyone? Bob |
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