single element rear wing vs multi element rear wing
single element rear wing vs multi element rear wing
(OP)
Hi can anyone tell me the difference between a single element rear wing vs a multi element rear wing.
Just want some brief info on the advantages and disadvantages. What happens with drag? Is there an ideal number of elements?
Just want some brief info on the advantages and disadvantages. What happens with drag? Is there an ideal number of elements?





RE: single element rear wing vs multi element rear wing
consider the aeroforce on the wing as the resultant of the lift and drag forces. so if you orient the aeroforce straight down you have zero drag, yes? note that the aeroforce is dependent on the AoA of the wing which'll change with speed (since the wing is fixed) so in reality ther'll be drag at some speeds (and thrust at others).
a multi-segment wing should generate more aeroforce than a single element. it is tricky to set up, you need the gap between the wings to be just right, the camber, etc need to be carefully designed.
RE: single element rear wing vs multi element rear wing
RE: single element rear wing vs multi element rear wing
RE: single element rear wing vs multi element rear wing
The reasons early aircraft had multi element wings was to reduce span due to the limited strength of construction materials.
Gliders are all very wide wingspan narrow section wings for a reason. Same applies to birds that live on the wing like an Albatross. Heck it even applies to sailing boats. A high aspect sail is more efficient and gives a better lift to drag ratio.
Regards
Pat
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RE: single element rear wing vs multi element rear wing
But you are ignoring the fact that Race cars using multi element foils have end plates that reduce the tip losses.
Think Boxkite.
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: single element rear wing vs multi element rear wing
The idea of a fence on a wing was controversially exploited by the design of the keel on the Aussie yacht, Australia 11 which won the Americas cup of the Americans after being held by them for something like 180 years.
http://en.wikipedia.org/wiki/Australia_II
I believe the advantage of the design was more lift per unit length of the keel. Draft was one of the measurements that was involved in the 12 metre formula, so more lift for depth gave a significant advantage under the 12 metre rule.
Also some model Boeing 747s had an upturned fence on the end of the wing so they could get more lift with a wingspan that still fitted within existing hangars I believe.
Regards
Pat
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RE: single element rear wing vs multi element rear wing
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: single element rear wing vs multi element rear wing
Failing that
http://ntrs.nasa.gov/search.jsp?R=20020060751&...
and other papers go into more detail than anyone could need.
Cheers
Greg Locock
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RE: single element rear wing vs multi element rear wing
I am very familiar with the winged keel design. In 1995 I was fabricating different sized wing cores for the New Zealand team so that they could change the size of the wings on their keel, based on what they thought the weather was doing.
With the multi element wing versus the glider/seagull wing ,you have two opposing ideals. With the glider/ seagull wing you are trying to produce within the limitations of the structure, an infinite wing span to reduce the tip losses and keep induced drag to a minimum thereby improving the lift to drag ratio. The max LD may not be the maximum coefficient of lift the wing can produce, but in a sailplane it does give you the most forward distance for the least loss of height .
The multi element short wing on a race car is striving for max CL( or downforce ) and does not care that much about lift drag ratio so is prepared to accept more drag in order to keep the wheels on the ground.
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: single element rear wing vs multi element rear wing
I am sure F1 would still rather have more down force for the same drag or the same down force for less drag or somewhere in between.
Regards
Pat
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RE: single element rear wing vs multi element rear wing
yes, end-plates are another design element that affect the aeroforce resultant from a wing (as Kenat says, by reducing the tip vortex), but the OP wasn't asking about them.
RE: single element rear wing vs multi element rear wing
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: single element rear wing vs multi element rear wing
I realise they adjust the wings for different circuits depending on if they want less drag or more down force.
My verbose fuddled comment above meant to say that they still want the best down force to drag ratio they can get while still delivering the required down force.
Regards
Pat
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RE: single element rear wing vs multi element rear wing
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: single element rear wing vs multi element rear wing