W06 Influenced CFD Study

[bhall II]

Fair warning: my inability to be brief is becoming more and more pronounced.

Enter at your own risk!

I think it pulls up because it is the upwash of the wing, it follows the general trend here. I don't understand how a low pressure under the nose would pull the y250 up. I'm not saying it's not happening, i don't understand.

Vortical flow tends to move from high-pressure areas to low-pressure areas just like any other stream. That's how you direct it from point-A to point-B (to point-C, etc).



On the nature of upwash: I don't know if the high-pressure areas in front of the wheels make it strictly impossible for any part of the front wing to create an upwash, but do I think it's mostly undesirable, as any flow that's not outwash subtracts from the strength of outwash.

That said, without proper end plates to entrain flow and increase dynamic pressure, I'm fairly certain that it's impossible for the inner-most sections of the wing to create an upwash, because local pressure adjacent to those areas will always be lower than the local pressure directly above them.



Bonus: the rationale behind certain mounting points for the camera pods is to keep air flow down. The horizontal portions, i.e. the actual camera housings, act upon freestream flow, and the stalks act upon flow over the nose, even though they've been somewhat neutered by the FIA. (We'll soon get to why I think such action is important.)

Mercedes pylons don't bend inward...

It's very subtle, evidenced only by the curve of the trailing edge, but the pylons do form a narrowing constriction nearest to the underside of the nose.



Feel like tearing down another baseless myth that's nonetheless widely accepted as fact?

There is absolutely no good reason for air flow underneath the chassis.

It's a pointless side effect of raised noses that are themselves designed to improve the quality of air flow to the bargeboard areas in order to generate strong "sealing" vortices under the flanks of the floor. Everything else is detrimental and should be avoided.

I don't want to bogart all the fun by spelling it out. So, let's see if others can put the pieces together.

What will happen to air flow through a "partial venturi" like the one formed by the W06 wing pylons? (The short-nosed F2012 sometimes featured an exaggerated version of the same.)


F2012

What effect will the turning vanes and "batwing" have on air flow under the chassis? (Click to enlarge)


W05


W06

What do the streamlines shown by the FloVis suggest? (Click to enlarge)


W06

In general, how does it all correlate to what's seen in this velocity field? (Click to enlarge)


(This image is --- great, by the way.)

Ok so you think that's what they do. That's amazing, how this thing reattach almost instantly at corner entry is quit an achievement. I can see how all the mess is diverted outside following the extrados of wing and flap but whoa. Maybe that's why they lift and coast, pure hard braking wouldn't allow this thing to work
W've seen lewis being caught quit a few times in qualifying last year (austria for example).

I'm not sure about Mercedes. My comment only concerns Red Bull's bendy-wings.

While I don't want to say pulling it off was easy, I think it was nonetheless pretty straightforward: they used specific carbon fiber layups to fashion the front wings into anisotropic structures, which means the wings required a combination of forces in order to flex. That property made for more consistent downforce/drag variability, because they more or less responded to the dynamic pressure of the air flow over them, regardless of the pressure underneath.

In other words, the flexing action was tied to the car's speed and essentially nothing else (which also foiled the FIA's old flex test, because it only measured vertical deflection).

The trick was tailoring the effect to suit a given circuit. I imagine the idea was to stall the wing at a threshold speed just beyond the highest cornering speed the car would be expected to encounter. Upon deceleration, the wing would resume creating downforce at the same speed, providing a decent chunk of time for air flow to stabilize prior to a corner.

If you go back to the McCabism article...

...downforce increases exponentially as the height of the wing is reduced. Beneath a certain critical height, however, the strength of the vortex reduces. Beneath this height, the downforce will continue to increase due to the venturi effect, but the rate of increase will be more linear.

...downforce variability on either side of the stall speed is comparatively gradual, which means changes weren't likely to be especially abrupt.

(I can't remember where I saw it, but it was rumored Red Bull brought unique wings to each circuit in 2011.)

[astracrazy]

Can i just say, bhall the time you put in to somewhat educating people especially in this thread is remarkable. Thank you.

[chuckdanny]

The acceleration of the flow under the nose tip has nothing to do with the pylons bending inward, the pylons are just allowing a better streamwise expansion by stoping a spanwise expansion, sealing effect, the main reason for wing car skirt, but it is more complicated than that with vortices forming in the nostril of the beast. That's where maybe, because i can't be as affirmativ as he is, the slight inward bending help the vortices to form.
I don't know why you take all what he says for granted, it looks like a guru without any opposition, that's ridiculous.
People always need a messiah, i don't, i'm the antechrist ahahahahahahaha

[bhall II]

Can i just say, bhall the time you put in to somewhat educating people especially in this thread is remarkable. Thank you.

I've had waaaay too much idle time lately.

But, I appreciate the sentiment.

[...]

Is that your way of saying you can't answer my question?

Hey, that's fair enough. We'll just go with your explanation.

The purpose of the constriction formed by the wing pylons is to stop spanwise expansion three inches before the turning vanes promote spanwise expansion.



Any resemblance to a venturi tube is purely coincidental.



Works for me!

(By the way, you totally missed the point.)

[chuckdanny]

What you call a turning vane, i already called it with a more appropriate name, a venturi vane, i learned nothing here!
I agree with your point of view converning the misconception of what high nose achieve.
And why is there a bird behind the elephant and his long trunk? (tusks could be vortex generating pylon)

The purpose of the constriction formed by the wing pylons is to stop spanwise expansion three inches before the turning vanes promote spanwise expansion.

Nop! the 1st part of the venturi vane is a convergent. The w06 nose is quit different especially at the inlet and with its pelican throat, yes there is a pelican also, it's the real Noah's Ark this w06

And i have already model this part, how could i possibly not know? i see an hammerhead shark here!

[bhall II]

The purpose of the constriction formed by the wing pylons is to stop spanwise expansion three inches before the turning vanes promote spanwise expansion.

Nop! the 1st part of the venturi vane is a convergent. The w06 nose is quit different especially at the inlet and with its pelican throat, yes there is a pelican also, it's the real Noah's Ark this w06

Funny stuff, huh?

It's nothing more than a deliberate rephrasing of your asinine suggestion, written in a way to highlight and contextualize the bizarre implications of your thought process.

The acceleration of the flow under the nose tip has nothing to do with the pylons bending inward, the pylons are just allowing a better streamwise expansion by stoping a spanwise expansion...

Still laughing?

Since I don't think you have a snowball's chance in hell of ever figuring out this stuff on your own, let me do the work for you.

Whenever you see wing pylons that are longer and/or more pinched at the top than they are at the bottom, a characteristic I've previously likened to "partial venturis," the idea is to ensure that the path of least resistance offered to incoming air flow is kept reasonably low.

This results in more favorable interactions between the air flow and the leading edge of the floor, because it increases mass flow to that area and reduces interference drag virtually everywhere between the front wheels.



It also reduces the size of the car's wake, albeit somewhat obliquely, which means form drag is decreased and the efficiency of downstream elements is increased. In that regard, the effect is very similar to what is/was achieved with the following elements...



And last, but certainly not least, with a little ingenuity and know-how, you can even create pure, unadulterated downforce on the spot.

i learned nothing here!

That's the problem!

Arguing with you is like arguing wih a brick wall, except mortar tends to be a bit more reasonable.

In any case, it's not fun, and I'm not going to do it anymore. So, I wish you the best of luck in your continued pursuit of knowledge.

[chuckdanny]

That's interesting but it is absolutly not what you were talking about, its typically of second or third order and this interference drag can be resolve by appropriate fillet and... and... nostril vortices mind you! Which create downforce so improve efficiency also. It's not dog's tail that moves the dog! (except some vortices that pretty much look like a dog tail )
I basically knew that also, pretty obvious, two frictions surfaces instead of just one will decelerate the flow create boundary growth and vorticity shedding, that's why they trigger vortices where this things happend as long as it is beneficial.
So no on this also you could be wrong they trigger streamwise vorticity.
You feel superior but you are not, just more time to read aero litterature, you didn't invent one of those thing, you can't even make the difference between tiny little details and main flow caracteristics, you are losing the big picture in tiny details in an evasive reply and in a ridiculous acting superior way.
And still are insulting but with me in front of you, you would shut up like a coward.

Bonus: the rationale behind certain mounting points for the camera pods is to keep air flow down.

Do you really feel like a genius on that? That's pretty obvious and why ? maybe because the wing create some upwash hm?
No, no upwash... ok!

[bhall II]

It's not your ideas that make you impossible; it's your peculiar willingness to argue vociferously despite...

the problem and i'm speaking about me is that although i know somes basics i tend to forget, i've got no reason to make memo of it or something.

Your post are long and well documented, i don't always spend the time needed to get what you try to explain i must admit. And sometimes i'm pretty stubborn and stop reading because i'm fealing that one part of the argument is wrong

That you seem to think upwash is the only reason for flow conditioners is the latest example of the former, and your apparent incapacity to recognize the subject of the conversation speaks volumes to the latter.

Now, I'm fully aware of my inability to suffer fools lightly and how my reactions to it constitute a character flaw. All the same, I still can't think of too many people who wouldn't eventually get really pissed off by a conversation that alternated between fiction and a complete disregard for opposing views.

That's why I'm done. I've shown my ass on this forum quite a few times, but it's been a while, and I'd like to keep that streak alive.

All the best.

[chuckdanny]

You seems to dislike any opposition, would like to be a dictator ?

I could act as you do and show you some thing and saying at the same time how stupid you are but i'm not an animal i don't feel the need to humiliate any opposition to piss everywhere to mark my territory. You know, some people have a life apart from the electronic forum. I accept other opinion but not insult, how many years you have been here? time to live maybe?

I will explain to you in the same manner as you do, the tip of the 2 flaps of front wing bend downward is it an aesthetic feature?
The start of the nostril of the redbull has been pushed backward, the nose tip is particularly close to the wing tip because there nose is a low but large one. How can this reduce the interaction between an upwash generating device and an upper face of the nose from which you would like the flow to go around and downward instead of over ?

Yes despite spending not 1% of the time you spend on aerodynamic i still can challenge, that's about intellectual efficiency
You would be perhaps interesting without this unfounded arrogance (are you french?) but...

[garygph]

You seems to dislike any opposition, would like to be a dictator ?

I could act as you do and show you some thing and saying at the same time how stupid you are but i'm not an animal i don't feel the need to humiliate any opposition to piss everywhere to mark my territory. You know, some people have a life apart from the electronic forum. I accept other opinion but not insult, how many years you have been here? time to live maybe?

I will explain to you in the same manner as you do, the tip of the 2 flaps of front wing bend downward is it an aesthetic feature?
The start of the nostril of the redbull has been pushed backward, the nose tip is particularly close to the wing tip because there nose is a low but large one. How can this reduce the interaction between an upwash generating device and an upper face of the nose from which you would like the flow to go around and downward instead of over ?

Yes despite spending not 1% of the time you spend on aerodynamic i still can challenge, that's about intellectual efficiency
You would be perhaps interesting without this unfounded arrogance (are you french?) but...

Gees dude give it a rest already! He has already stated that enough is enough and does not want this back and forth to continue on this destructive path you seem to be determined on continuing. I for one like his approach and explanations which he takes time to explain so well that even I can "get it". The way you reply is not necessary or productive and possibly if you enjoy this forum so much you should have a look at so that we can all enjoy constructive discussion.

[CBeck113]

You seems to dislike any opposition, would like to be a dictator ?

I could act as you do and show you some thing and saying at the same time how stupid you are but i'm not an animal i don't feel the need to humiliate any opposition to piss everywhere to mark my territory. You know, some people have a life apart from the electronic forum. I accept other opinion but not insult, how many years you have been here? time to live maybe?

I will explain to you in the same manner as you do, the tip of the 2 flaps of front wing bend downward is it an aesthetic feature?
The start of the nostril of the redbull has been pushed backward, the nose tip is particularly close to the wing tip because there nose is a low but large one. How can this reduce the interaction between an upwash generating device and an upper face of the nose from which you would like the flow to go around and downward instead of over ?

Yes despite spending not 1% of the time you spend on aerodynamic i still can challenge, that's about intellectual efficiency
You would be perhaps interesting without this unfounded arrogance (are you french?) but...

You've admitted that you "play" with cdf and are learning in the process, and get a free course from an experienced aero engineer, and you want to tell him a) he's wrong and b) you can't learn anything here?!? I cannot believe your arrogance - you've been pissed off with him since he told you that your "Mercedes W06 Front Wing" won't be the W06 front wing, which was correct from him - another free lesson - and you continuously show that you are the one who is arrogant. Your intellectual efficiency is on par with flushing a toilet; no matter what goes in it is all handled like ---.

Do yourself a favor: listen to the people who have been around for years here; they have lives outside of this forum, but also have direct or indirect professional practice with the theories being discussed here...and most of them know more than you.

[bhall II]

...a free course from an experienced aero engineer...

You're not referring to me, are you? 'Cause I'm not an engineer.

In any case, it appears chuckdanny and I were talking about two different things, and the conversation went off the rails thanks to a couple of misconceptions/misstatements.

His line of thought concerned the use of the wing pylons as partitions to separate the outer wing from the neutral center section, and I think he was probably correct to point out why that's beneficial.

That said, it's not at all what I was talking about, and I believe it may very well be impossible for an explanation to miss its intended target by a wider margin than the one offered here. Had it been a recipe for cake, we would have ended up baking a bicycle.

To start, talk of convergence/divergence immediately shifted my focus to venturi tubes...



...since I don't often see those words used in this context for anything else. Plus, my theory that front wing pylons create "partial venturis" was the last thought I conveyed prior to that response. So, it never occurred to me that the conversation was elsewhere, which then made subsequent comments about "spanwise expansion" or "sealing effects" seem downright absurd.

The acceleration of the flow under the nose tip has nothing to do with the pylons bending inward, the pylons are just allowing a better streamwise expansion by stoping a spanwise expansion, sealing effect, the main reason for wing car skirt...

Even in the proper context, I'm still not sure I agree with the above assessment. But, it is indeed a helluva lot more appropriate, if not more plausible, in a conversation about pylons-as-partitions than it is for one about pylons-as-venturi. That's just madness. (Hence my reaction.)

[Just_a_fan]

A useful image to help see what part of the air flow behind the front wheels is doing on the W06. Bear in mind the tyre is locked so the usual rotation isn't there but the way the wake flows outward and doesn't come back towards the car until the coke bottle tucks in is quite clear.



This must result in relatively "clean" air impinging on the front of the floor below the side pods.Also, if the air flow is being directed outwards then there must be air pushing it that way (or at least being able to replace it) from the space between the tyre and the monocoque. This suggests that the air coming from the front wing is being used - the turning vanes below the nose are presumably involved in this overall pattern. The shape of the side pod undercut will have a turning effect too, of course, but the smoke is moving outwards long before it might be expected to "feel" that effect. A really interesting image.

Shame we can't see some smoke from a leading car going through the front wing / below the nose...

[chuckdanny]

I think the sidepod undercut is the main turning force actually, like the bow of a boat, the frontal area is the biggest of all aero part, major influence. It's like a leading edge of a massive wing without stagnation point but not very thin, the equivalent thickness of the f1 width... ***
What i didn't see first is the front wheel inner cover, it is the main reason for the clear air inside, it clears the wake that arise from the leading edge let's say of the tire, the Y250 also plays its role and the so called wheel nut blowing.
The front wing vertical elements (3rd element plus 2 flaps) allow the very clear (laminar) airflow passing underneath the wing a big clear vertical space to expand, creating a big diffuser with a big aspect ratio.

***
Do we know another animal for noah's arc (god's sake) that similarly cut the stagnation point? Yes the swordfish!
Well there is this study about it
http://journals.plos.org/plosone/articl ... ne.0081323

Excerp :
" Aleyev [7] compared the static pressure distributions along the dorsal, ventral and lateral midlines on swordfish models with and without bill, and showed that the bill prevents high pressure near the anterior part of head and shoulder, indicating possible reduction in the form drag by the bill. However, this result alone is again insufficient to determine whether or not the total drag is indeed reduced by the bill because of possible changes in the skin friction distribution."

Morality : if you pay your bill you still have friction

F1technical and lucas art present : THe w06 front wing vortex system

[chuckdanny]

Talking about animals, this thing is between deer and moose horn



I've got at least this y250 area streamwise acceleration, remember that toro rosso screen picture


And quit interestingly i had a gap too small for my mesh resolution between the 1st flap, the lowest one and the 3rd wing element which affected the Y250 and... this 3rd element partially stalled till the slot near the arches.
Maybe it's an hallucination but i like the idea...



Another interesting feature, the vortices shed by the turning winglet are merging and like captured by the V section between the arches and the end of the wing where gurneys are trimmed. Maybe it controls precisely the position of this vortex downstream? maybe not, don't know, just an idea.