Honda's conditioner wing?

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100cc
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Honda's conditioner wing?

Post by 100cc » Fri Jun 04, 2004 5:18 pm

Does anybody know what effect this wing has on the airflow to the rear wing?

West
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Post by West » Fri Jun 04, 2004 7:57 pm

It should smooth the flow into something more laminar; something more useful.
Bring back wider rear wings, V10s, and tobacco advertisements

Asphodel
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Post by Asphodel » Sat Jun 05, 2004 10:05 am

Any surface is going to create vorticity and I doubt it could make the flow more laminar. I think the wings are there to provide extra downforce for the car. However, they don't want to disturb the flow going onto the rear wing too much so that is why it has a low Angle of Attack. If it was only there for conditioning the flow, then why is it not symmetric? Eventhough the wing might have a low lift to drag ratio, it is still providing downforce closer to the vehicles centre of pressure without affecting the rear wing too much.

Monstrobolaxa
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Post by Monstrobolaxa » Sat Jun 05, 2004 11:22 am

Asphodel is correct.

Irvingthien
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Post by Irvingthien » Sat Jun 05, 2004 12:06 pm

Any pictures???

Asphodel
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Post by Asphodel » Sat Jun 05, 2004 1:48 pm

I think it is strange that the mid mounted wing on the Ferrari doesn't have endplates. Wouldn't it make the wing more efficient by stopping the air spilling around the end of the wing. I am open to any ideas of why they don't do it. Is there something in the rules?

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Post by Monstrobolaxa » Sat Jun 05, 2004 2:14 pm

Once again you are correct Asphodel that is why most airliners now have winglets on the end of the wing...and there is another device that is being developed called Minix, these parts that are adapted on the end of the wings reduce the voticity (which increases drag) caused at the tip of the wings.

Asphodel
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Post by Asphodel » Sat Jun 05, 2004 4:17 pm

That Minix is a very interesting conceopt. I was having a think about the idea of putting end plates on the wing and I think it the problem could be due to yaw. When the car is turning into the corner, that is where you need the downforce. if the flow isnt normal to the flow and it had end plates, it could have a large effect on the downforce. The downforce might not be consistent and make it hard for the drivers judge the correct braking force.

seymour
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no endplates

Post by seymour » Sat Jun 05, 2004 5:34 pm

I think the mid mounted wings don't have endplates on purpose. I can't back up my suspicions with any cfd, but I wouldn't be surprised to learn that the tip vortex created by the mid mounted wing increases pressure over the rear wing at lower speeds (turning) increasing downforce and decreases pressure at higher speeds (straightline) reducing drag. Furthermore, the speed of transition and location of the pressure change would be tunable by altering the length and shape of the wing. This would explain why Ferrari has brought different length wings to different circuits.

It also might explain why the wing has not been adopted by everyone: it is likely an extremely complex system to model and build properly and possibly beyond the resources and abilities of some teams.

Reca
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Post by Reca » Sat Jun 05, 2004 5:55 pm

An airfoil optimised to work at low AoA hence low Cl (like the midwing) is way more efficient than an airfoil with a very curved camberline designed to obtain very high CL (like in the rear wing). So if you are able to generate even a small amount of the total downforce of the car from the midwing (I wouldn’t be surprised if it was in the order of 1-2%), you can reduce by the same amount the downforce from the rear wing, increasing its efficiency and the overall efficiency of the car. Then there are further details to analyse, like the downforce distribution Asphodel was referring to and the pitching moment, clearly lower for airfoils with a small curvature of the camberline.

Apparently Ferrari is using the midwing to improve the overall efficiency also on low downforce configuration, this week in Monza Badoer was testing with it and the overall package was undoubtedly for low downforce.
B.A.R. and Williams on the contrary weren’t using it so probably for them it’s mainly an additional device to reach an higher level of downforce, that could be confirmed also from the fact that the one on the B.A.R. has a span apparently as wide as rules allow in that area (max 60 cm).
Asphodel wrote: I think it is strange that the mid mounted wing on the Ferrari doesn't have endplates. Wouldn't it make the wing more efficient by stopping the air spilling around the end of the wing. I am open to any ideas of why they don't do it. Is there something in the rules?
Maybe the gain would be minimal and probably the increased surface would cause bigger drag and maybe more disturbance to the flow downstream. Consider also that the effect of the endplate is a redistribution of the lift on the span, basically a virtual increment of the aspect ratio, hence of the span. As I’ve said above F1 rules actually impose a maximum width in that area but only BAR is apparently using the full span, others could easily increase it if required. Ferrari did the opposite, reducing the span in Imola compared with the previous model and keeping the same short span also in Monaco. That suggests that the increment of span would carry little benefit if any. Then I’ve a little voice in my head saying that it’s no coincidence that the width is about the same of the camera housing just above it ;-)
Monstrobolaxa wrote: that is why most airliners now have winglets on the end of the wing...
The usual motivations to use the winglets at the tip on airlines are :
1. A new model of the same airplane with increased maximum take off weight and payload (usually thanks to a longer fuselage). The wing is one of the most complex things to design and it’s cheaper to use a bit more AoA in cruise limiting the increment of drag thanks to the winglets instead of a complete redesign of the wing aerodynamics and structure, many airplanes of the same manufacturer share the same wing.
2. Airports requires to pay a tax that is related with the size of the airplane and based usually on the span of the wing. The winglets allows to mimic an higher aspect ratio (larger span) without actually increasing it.

In absence of these limitations (or similar) it’s usually preferred not to use the winglets at the tip but to increase the aspect ratio instead.

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Post by Monstrobolaxa » Sat Jun 05, 2004 7:04 pm

2. Airports requires to pay a tax that is related with the size of the airplane and based usually on the span of the wing. The winglets allows to mimic an higher aspect ratio (larger span) without actually increasing it.
- Reca

(I don't really know how the quote works :lol: )

Humm...well I've had a Airliner Mangment class (I'm in aeronautical engineering) according to what we studied the airport taxes are not based on wingspan they are based on weight to be more precise the maximum take-off weight x $$$$per ton. In certain cases when the airport is close to its capacity in terms of handling and/or "parking spots" it will apply a special fee for wide bodied aircrafts. (prices for the weight (average) up to 25 tons - 5 euros/ton, 25 to 75 - 5euros/ton, over 75 - 7euros/ton...this is only for the aircraft airliners also have to pay an extra feww for each passenger carried)


About the wings....with the introduction of the winglets Boeing was able to to reduce the wing area by 20% due to the lift gained, in the 747. In the previous post I also forgot to mention that the winglets also prevent the airflows from the top of the wing and bottom from mixing thus producing a reduction in the lift and increasing the drag. In some plans in the A320 family the winglets produce an average 1,7% reduction in drag.

And yes some planes have the same wings.....in Airbus especially Airbus is divided into families: A320/18/19/21, A330/40, A300/310 and A380. In the families the wings tend to be the same from aircraft to aircraft. In Boeings case they tend to design a new wing for each family like Airbus but in Boeings case they also design new wings for old models.....the 747 has 5 or 6 diferent wings (like mentioned preivously the first 747's flying had bigger wings) and the 737 family has also quite a few diferente wings (but in any case these 2 are planes that have 40 years and the newer models have new wings)

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Post by inspectah » Sat Jun 05, 2004 11:15 pm

It also might explain why the wing has not been adopted by everyone: it is likely an extremely complex system to model and build properly and possibly beyond the resources and abilities of some teams.
You mean teams like mclaren? :lol:

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Post by Monstrobolaxa » Sun Jun 06, 2004 1:40 am

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

Reca
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Post by Reca » Sun Jun 06, 2004 7:54 am

About the taxes, that was what my Aerodynamics lecturer said to us while talking about the winglets, it was a few years ago. Maybe it was an old rule or maybe it works this way only in some countries/ for some categories of airplanes, I never verified cause I’m not really interested in that kind of problems. Maybe he was simply wrong.
Monstrobolaxa wrote: with the introduction of the winglets Boeing was able to to reduce the wing area by 20% due to the lift gained, in the 747
20% less area means a 20% higher Cl, that can’t be due to the winglet alone, that’s the effect of an overall new design. Manufacturers always work to reduce the area of the wing or, better said, to increase the wing load (weight / wing area) one of the reasons being that it reduces the sensitivity to the turbulence but obviously also the reduced dimensions of the wing (hence of its weight) is a pro. Then you have just to find room for the fuel...
The figure you mentioned later about the A320 (1.7%) is a more plausible indication of the effect of the winglet alone.
Monstrobolaxa wrote: In the previous post I also forgot to mention that the winglets also prevent the airflows from the top of the wing and bottom from mixing thus producing a reduction in the lift and increasing the drag.
That’s indeed the effect of the winglet, the reduction of the vorticity you previously mentioned is just the same thing, an effect of the reduced mixing. And clearly that’s the same effect you have increasing the aspect ratio of the wing, a reduction of the induced drag and a modification of the distribution of lift across the span. I didn’t say that the winglet doesn’t work, I just said that it’s the solution used mainly if there are limitations to the span.

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Post by Monstrobolaxa » Sun Jun 06, 2004 2:42 pm

Well the figure I mentioned about the 20% area due to the winglets I read it in one place....and heard it in a discovery channel dcumentary.

the book:
"Boeing Aircraft Cutaways" (Osprey Aviation), Mike Badrocke (Illustrator), Bill Gunston, 1999