Do winglets produce thrust?

Anyone?
Bob

"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

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.

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Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA

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.

"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

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

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.

Bob Salvo wrote:

Anyone?
Bob

Yes

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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)


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Denis
Private replies: remove "moncourrielest" from my e-mail address
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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