Pescarolo's Wobbly Bobbly Wings

[wesley123]

that is possible though quite weird with the low AoA they run for Le Mans

[godsire]

Can anybody post a sample profile of its rear wing? I would like to make such wing and simulate it using CFDesign but I have no idea about its profile. Of course I will post all my results here

Btw. What does "AoA" means?

[Sawtooth-spike]

Angle of attack

[horse]

This paper here might shed some light. Inspired by dragonfly wings to create a less draggy Gurney flap.

Drag reduction of airfoils with miniflaps. Can we learn from dragonflies?

[Holm86]

http://www.gizmag.com/bumpy-whale-fins- ... mics/9020/

Here is an article on those whale fin bumps i was talking about. To me this seems as what they are trying to duplicate.

[Ciro Pabón]

I think they are vortex generators. You use them to increase energy in the air flow (twirl it) so the laminar flow on the surface doesn't detach at large angles of attack. They also have more benefits, if you believe the inventor. Read the link (or the one provided by Holm86).

I repost what we wrote here: viewtopic.php?f=6&t=5416

They are not legal.

I think this is similar enough to the idea you propose, taken from "A whale of a tale".

WhaleCorps turbine blade


Ginsu said in that thread that there was a third, previous thread on the subject, which I could not find (he did not provide a link to it). DaveKillens mentioned vortex generators, they all seem similar to a profane: eagles, sharks, tunas, whales, they all "taste like chicken" to me.

This is an image Dave provided that I think sums up the "principle" behind vortex generators. Maybe humpbacks humps (shouldn't they be called "humpfins"?) work in a similar way:



I think most of them (VGs) are used to avoid stall at extreme angles of attack, as Giblet mentions. In the earlier thread some people said they increase drag when the angle of attack is low.

Finally, on the subject of bionics, I smiled with these pictures: http://www.freakingnews.com/Insect-Airc ... --1133.asp

[DaveW]

... & I was convinced they had laid up bubble wrap by mistake....

[JMN]

Sounds remarkably similar in effect to the benefit from dimples:
[youtube]http://www.youtube.com/watch?v=-oHMEvZC ... BA4AAF1C81[/youtube]

[Giblet]

Woah, funny thing is I never looked at the title of that blog, I just skimmed the article and it did indeed go into detail like the one I had read years previous.

I would like to say that I neither endorse or promote anything to do with that blog.

Here seems to be a better article on the same study, without any strange slants.

While I am at it I would like to post an idea from the site halfbakery.com that I posted in 2005 here.

Still I find this wing very curious and one of the funniest looking things to see on a car in a long time.

[Formula None]

This thing looks great.

[Formula None]

[Formula None]

[xpensive]

How bizarre, but it shouldn't be to difficult to confirm with modern CFD or a windtunnel, no? But knowing the French and their ways, this piece has surely never been tested that way, it looks far too cool to be ruined that way...

[zgred]

Sounds remarkably similar in effect to the benefit from dimples:

Wind turbines inspired by Whales

Kat - (...) is this similar to the dimples on golf balls? Is it a similar function that’s going on?

Frank - It has similarities, but there are distinct differences. What a golf ball does by having the dimples on it is to turbulise the air over the surface of the golf ball. So normally air will move in nice, even layers over a surface, and that’s what we call laminar flow. The trouble with laminar flow is it’s not very stable. You can't maintain it at very high speeds or with very large entities. And so, by having the dimples that turbulise the flow over the golf ball, which means that the flow will continue over more of the surface, and as a result, there’s less resistance, and the ball travels further when it’s hit. With the tubercles, or these bumps along the leading edge, what they do is they do create a different flow regime, but not necessarily turbulising the flow. What they do is they produce large swirling masses of flow, what are called vortices. These vortices interact over parts of the wing to actually help to speed up the flow over say, the bump itself and keep that flow attached over the entire surface of the wing, so that again, you don't stall out.

Whale Fins Influence Wind Turbine Design

[djhache]

But there's a distinct difference between whale fins and this wing: namely the fact that whale fin bumps re-energize the flow over the low-pressure side and the bumps on the Pescarolo wing are on the high-pressure side, that and these bumps are quite smooth as oppose to the very small dimples on a golf ball that can induce turbulent flow.

By the way, I know the Pescarolo boys have plenty of smart guys who can handle CFD and wind-tunnel testing and there's enough aerodromes near Le Mans to run intelligent straight-line tests. If they put the bumps on the car it's likely they have a reason for it!