Reducing the drag of a two element wing through stall

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Reducing the drag of a two element wing through stall

Post

I did over a new wing, this time i used one of the twitpics of a Williams wing section to guide me in making my main element. I used the regulations to set the wing size, width, bridge wing, diffuser and end plates.
I have come to realize that F1 wings have some separated flow towards the center of the wing.
A third element or "hole" has to be put in between the area 75mm from the center line.
Regulations only allow 2 sections beyond that distance.

Regulations also state that the slot gap should not exceed 15 mm at the closest distance between the 2 wing sections. That is a major difference between what i had before and what slim jim has, my gap being too small and his gap seemily greater than 15mm.

The hole in the wing really helped out, but the center still has a small separated area above the hole slot.
I will post some pics up soon. With that i think the major difference with the current F1 wing is that some separation exists, and this is why stalling doesn't change much of the numbers .
gimme a sec I'll have some pics up after i run back the tests.
For Sure!!

User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Reducing the drag of a two element wing through stall

Post

Image

here's an example of what i was saying earlier, there needs to be a slot or hole on the main element towards the center. It's difficult for the air to crawl up that steep incline on the back. My first wing failed because of the lack of slots and too much camber. Looking at the Ferrari wing, it's not as cambered as the Mclaren.

Image
For Sure!!

User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Vodafone Mclaren Mercedes MP4/25

Post

outer_bongolia wrote:
ringo wrote:About the snorkel, i think it's just there to cool the drivers for Bahrain.
Remember what happened to Alonso last year?

There was a pic with Button getting out of the car. I think i saw his shin through the snorkel hole. So it's just a little vent for extra cooling. Driver comfort is very important if you want to get 100% out of them.
Hey Ringo, if you remember where you saw the picture, would you mind posting it? That would be cool.
can't find it, it was from Thursday's test. #-o
He was climbing out in the garage, could have sworn i saw his shin (white wrinkled material) through the hole.
I am still looking for it, can't remember if i saw it on this site or elsewhere.
For Sure!!

User avatar
outer_bongolia
5
Joined: 13 Feb 2009, 19:17

Re: Vodafone Mclaren Mercedes MP4/25

Post

ringo wrote: can't find it, it was from Thursday's test. #-o
He was climbing out in the garage, could have sworn i saw his shin (white wrinkled material) through the hole.
I am still looking for it, can't remember if i saw it on this site or elsewhere.
Cheers, don't worry... I just thought it would end discussion on the knee-control of the rear wing blower. Thanks for looking for that!
Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.
Carl Sagan

Giblet
Giblet
5
Joined: 19 Mar 2007, 01:47
Location: Canada

Re: Vodafone Mclaren Mercedes MP4/25

Post

ringo wrote:About the snorkel, i think it's just there to cool the drivers for Bahrain.
Remember what happened to Alonso last year?

There was a pic with Button getting out of the car. I think i saw his shin through the snorkel hole. So it's just a little vent for extra cooling. Driver comfort is very important if you want to get 100% out of them.
What happened to Alonso had nothing to do with heat directly. His drink system broke, and he became extremely dehydrated.
Before I do anything I ask myself “Would an idiot do that?” And if the answer is yes, I do not do that thing. - Dwight Schrute

tok-tokkie
tok-tokkie
36
Joined: 08 Jun 2009, 16:21
Location: Cape Town

Re: Reducing the drag of a two element wing through stall

Post

horse wrote: I'm not sure a moment about the rear wheels is that desirable anyway. If you push the back down then you will lift the front at the same time.
Whether it is desirable or not it is the reality.

User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Reducing the drag of a two element wing through stall

Post

It has to be ballanced by the floor and the front wing. But it isn't really a big problem because the wing is pretty close to the rear wheel, so the moments aren't a task to balance.

Anyway, here's the wing, added a little ferrari inspiration to the central hole.

Image

Image

diffuser is basic, not DDD.

Image

flow is attached to the sides more than the centre of the wing. Upper element's flow is attached throughout because of the slot. Much better improvement than my first attempt which was just a 2D wing which doesn't tell the whole story.
Lift to drag ratio is 1.834 with down-force of 136 lb. on the wing alone :lol:
the last one i did was 0.7 L/D. :oops:
For Sure!!

User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Reducing the drag of a two element wing through stall

Post

Will put up the rest later.
For Sure!!

User avatar
ringo
227
Joined: 29 Mar 2009, 10:57

Re: Vodafone Mclaren Mercedes MP4/25

Post

Giblet wrote:
ringo wrote:About the snorkel, i think it's just there to cool the drivers for Bahrain.
Remember what happened to Alonso last year?

There was a pic with Button getting out of the car. I think i saw his shin through the snorkel hole. So it's just a little vent for extra cooling. Driver comfort is very important if you want to get 100% out of them.
What happened to Alonso had nothing to do with heat directly. His drink system broke, and he became extremely dehydrated.
Yes his drink system failed, but it was critical because of the cockpit temperatures. Which has to do with heat directly. :wink:
Barichello didn't do so well either because he was being burned on his hip by the tub.
The extra cooling from the snorkel would have the drivers feeling less miserable and able to focus on the driving.
If i could only find the pic showing Jenson's feet through the snorkel. ](*,)
For Sure!!

Just_a_fan
Just_a_fan
591
Joined: 31 Jan 2010, 20:37

Re: Reducing the drag of a two element wing through stall

Post

ringo wrote:It has to be ballanced by the floor and the front wing. But it isn't really a big problem because the wing is pretty close to the rear wheel, so the moments aren't a task to balance.

Anyway, here's the wing, added a little ferrari inspiration to the central hole.

Image

Image

diffuser is basic, not DDD.

Image

flow is attached to the sides more than the centre of the wing. Upper element's flow is attached throughout because of the slot. Much better improvement than my first attempt which was just a 2D wing which doesn't tell the whole story.
Lift to drag ratio is 1.834 with down-force of 136 lb. on the wing alone :lol:
the last one i did was 0.7 L/D. :oops:
Be interesting to see if a central support pillar makes a big difference. Also a straight comparison of the wing with and without the additional central hole. Lots of work to run though, I guess.

What software are using to make and test these models?
If you are more fortunate than others, build a larger table not a taller fence.

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: Reducing the drag of a two element wing through stall

Post

horse wrote:
autogyro wrote:If the wing only worked to produce lift (negative) there would be no reason to have such a steep angle of attack
I think you're forgetting that the flap element also effects the main element. Having the flap element improves the down force generated by the main element.

I'm not sure a moment about the rear wheels is that desirable anyway. If you push the back down then you will lift the front at the same time.
autogyro wrote:Useless on an aircraft.
Flap angles get pretty steep, but the wings are not stalling.

Image
Correct but on an aircraft it is a compromise. The flap is moveable and the wing has GOT to revert to a sensible lift drag condition for main flight conditions.
Also consider how much of the 'u2' extended flap form factor drag contributes to lift? It certainly acts as an airbrake augmented by the fuselage airbrakes shown which are a copy of the Hawker Hunter brakes.

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: Reducing the drag of a two element wing through stall

Post

Sorry but the U2 flaps shown also make the aircraft adopt a nose down attitude for landing to give better pilot vision and a steeper more acurate approach angle in the glide path.
the actual flap angle to decent angle is less than the flap to chord line angle.
On an aircraft the pitch angle of the whole aircraft is a factor.
This is not the case for a car.

autogyro
autogyro
53
Joined: 04 Oct 2009, 15:03

Re: Reducing the drag of a two element wing through stall

Post

Nice work ringo.
What is the range of vehicle speeds you are using?

jason.parker.86
jason.parker.86
1
Joined: 29 Mar 2009, 21:57

Re: Vodafone Mclaren Mercedes MP4/25

Post

I think the snorkel is a long term mod, why else would they insist on running it on 90% of the test?

Out of interest, what was that vent on the nose that Ferrari had a few years back for? Cooling or aero?

greenall
greenall
0
Joined: 27 Feb 2010, 23:02

Re: Vodafone Mclaren Mercedes MP4/25

Post

jason.parker.86 wrote:I think the snorkel is a long term mod, why else would they insist on running it on 90% of the test?

Out of interest, what was that vent on the nose that Ferrari had a few years back for? Cooling or aero?
Must be closable then, if we have rain heavy again (was it bahrain or malasia?) jenson and lewis will be needing armbands in the cockpit :wtf: