What's the logic/science behind the massive end plates?
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Originally Posted by Dr Pooface
(Post 962003)
What's the logic/science behind the massive end plates?
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Originally Posted by Dr Pooface
(Post 962003)
What's the logic/science behind the massive end plates?
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The wing works by creating a higher pressure on top than on bottom. Without end plates, the pressure would "spill" over the edge creating a vortex, decreasing the downforce created and increasing the drag. Endplates prevent this. In general, the bigger the better.
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I thought the end plates were supposed to have equal height above and below or biased towards being above the wing rather than below it.
I flew yesterday and the end plate on that wing was interesting. May just flip that design upside down and look fannccyyy. |
Originally Posted by ericwh
(Post 962051)
I thought the end plates were supposed to have equal height above and below or biased towards being above the wing rather than below it.
There is a Racecar Engineering article I have at home that had a lot of data on wing end plate depth. I'll scan it when I'm back there after Christmas. |
Originally Posted by ericwh
(Post 962051)
I thought the end plates were supposed to have equal height above and below or biased towards being above the wing rather than below it.
I flew yesterday and the end plate on that wing was interesting. May just flip that design upside down and look fannccyyy. |
Sooo many of the wings on the market have terrible endplate designs. I have to assume it's just a trade-off decision; they assume the wing won't sell with a big form>function monstrosity of an endplate ;)
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Another reason end plates tend to be larger on bottom is because regulations often require that no part of the wing protrudes higher than the roof line of the car... and since you want the wing itself placed up high to get into the cleaner airstream, it doesn't leave much room for a large end plate above the wing.
A really good design would use uprights as end plates. |
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Originally Posted by Dr Pooface
(Post 962003)
What's the logic/science behind the massive end plates?
Large endplates seen on open wheel race cars do serve a purpose. It is intended to reduce the effect of the "dirty" air disrupting the airflow to the wing.
Originally Posted by NiklasFalk
(Post 962024)
Aerodynamic Yaw-angle stabilizers ... :)
Originally Posted by Handy Man
(Post 962040)
The wing works by creating a higher pressure on top than on bottom. Without end plates, the pressure would "spill" over the edge creating a vortex, decreasing the downforce created and increasing the drag. Endplates prevent this. In general, the bigger the better.
Originally Posted by ericwh
(Post 962051)
I thought the end plates were supposed to have equal height above and below or biased towards being above the wing rather than below it.
I flew yesterday and the end plate on that wing was interesting. May just flip that design upside down and look fannccyyy.
Originally Posted by Leafy
(Post 962055)
Nope, you want it biased to the bottom. Because an efficient wing should create the majority of its force from the low pressure at the bottom of the wing, so you're going to have a lower pressure under the wing so air is going to want to flow into there from the sides more.
Originally Posted by ThePass
(Post 962066)
Sooo many of the wings on the market have terrible endplate designs. I have to assume it's just a trade-off decision; they assume the wing won't sell with a big form>function monstrosity of an endplate ;)
The much greater low pressure at the bottom can be seen in this cfd pressure plot below. This is of a wing I currently in the process of designing (except now it uses my own airfoils that I designed instead of one available). The current iteration performs much better ;) Attachment 185686 This is a cfd pressure plot across the wing to show how endplates interact with the airfoil. This is my current single element design (endplates still being optimized). Also this is one tested on a Miata so this is not seeing all free-stream air. Attachment 185687 |
Awesome!
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Originally Posted by ThePass
(Post 961956)
Hmm I see what you are saying. But, don't know how you figure there is more frontal area. Same number of bolts, same thicknesses of materials, in fact using the same exact hardware too. If you mean the frontal area shifted because the bolt locations moved, that I agree on.
As for the rear hole, as great as it is in theory, the carbon was already F'ed up from mounting/dismounting in its previous life because that hole is so close to the airfoil. I knew if I used that hole, through just tool contact, mounting/dismounting, etc. it would get a lot worse. I'd like to avoid causing a weak point in the airfoil over time. The other thing I took into consideration was that the front holes stuck wayyy down low - this meant the angle of the uprights would have to be more severe because they would have less height in which to make the transition. I wanted to minimize the angles of the bends to keep the aluminum as strong as possible. As it is, they are only 7* and 9*. |
Endplates cause vortices also. Also without an endplate, drag would most likely be reduced since the induced drag would be decreased. Bigger isn't always better. Proper analysis and testing is better. For some great info on the subject check out these articles from Racecar Engineering: http://www.rightwheeldrive.com/Aero_articles.zip |
Originally Posted by Handy Man
(Post 962388)
Surprisingly not. Adding end plates to most automotive style wings actually decreases drag while increasing downforce. Free Lunch! woohoo!
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Originally Posted by plucas
(Post 962118)
Originally Posted by NiklasFalk
(Post 962024)
Aerodynamic Yaw-angle stabilizers ... :)
It's based on the logic when the center of aerodynamic pressure (seen from the side) is behind the center of mass the car will straighten when it gets sideways. This was one of the design objectives with the COT body design and it apparently worked since the COTs could drift a lot longer when the old style spinned. Usure if the Miata (with normal HT) is aerodynamically unstable or stabilized this way. F1-style dorsal fin? :D |
The big difference is that COT's are going 200+ mph and we are going a LOT slower.
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Hustler likes wings with balls.
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What's with the balls?
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