Red Bull RB10 Renault

[timbo]

I would not say that. The only really useful meaning is, that they have done 60% of the work they had on their plan until now.
And this sounds very reasonable: Now they have their first full race simulation...so they are where they wanted to be at the beginning of the first Bahrain test.

It looks like a new definition for potential But yeah, it's plausible.
Anyway, even if it's true it is impossible to quantify performance improvement from it.

[simieski]

That was rhetorical. Problems with statesments like "engine is at 60% potential" is that it can mean anything. Say engine is capable of producing 700hp, but produces only 699hp 60% of the time. It is clearly at 60% of its potential. But in terms of laptimes it translates to very small difference. Same can apply to any metric -- incl. torque, consumption, reliability etc.

I'm not sure I agree with these statements. I don't think power and time can be interchanged quite this simply. If you assume the potential power to be 700 bhp, 699bhp in comparison is 99.857% of this. Time spent at this is a separate, and not an interchangeable value when discussing potential.

[timbo]

That was rhetorical. Problems with statesments like "engine is at 60% potential" is that it can mean anything. Say engine is capable of producing 700hp, but produces only 699hp 60% of the time. It is clearly at 60% of its potential. But in terms of laptimes it translates to very small difference. Same can apply to any metric -- incl. torque, consumption, reliability etc.

I'm not sure I agree with these statements. I don't think power and time can be interchanged quite this simply. If you assume the potential power to be 700 bhp, 699bhp in comparison is 99.857% of this. Time spent at this is a separate, and not an interchangeable value when discussing potential.

Of course, but as a press speech anything goes. What Horner said is simply not a technical term or definition and we can deduce whatever we like. That is my point.

[shelly]

I think that the new slots in the rear are not for reducing drag, but to aid downforce of the rw.

They are placed below the wing profile - pressure is highr outside the endplates than inside in that zone

Rbr have had to fit the rw into the new legality box, so if the wing is aggressive the rear of it is steep, it needs slot bleeding from outside of rw not to stall. same as on the ouside of front wing endplate on most cars (for example f14t)

I think Scarbs is probably right on this one.

http://i.imgur.com/soWgpNk.jpg
2014 (top), 2013

To minimize the loss of downforce caused by the new wing regulations, I think Red Bull have chosen to increase pressure over the wing through the omission of the usual slots featured in end plate designs seen up and down the grid. Such a slot-less layout softens the impact of the new restrictions, because it essentially exchanges pressure for pressure.

Be it from a comparatively large wing with slots, like before, or from a smaller wing without slots, like now, it's all the same, yanno?

At least, I think so...

The downside would be drag caused by strong tip vortices shed from a system no longer equipped with a mechanism to bleed high pressure from the top of the wing. Left alone, the increased pressure differential compared to air flow on the underside of the wing would likely cause very strong vorticity at the wing tips, and the car would then be penalized by the high drag such a condition tends to create. The new slots appear to be a means to combat that problem, but in a reversal of the way end plate slots are normally used.

Here, they actually increase local pressure under the wing at a point just prior to vortex formation in order to minimize the pressure differential when that stream combines with its high-pressure counterpart from above. This subsequently weakens the vortices formed as a result of that interaction.

The slots will cost a bit of downforce relative to the entirely slot-free end plates the team used throughout winter testing, but not by much, and the drag reduction will make it worthwhile. In the end, I think the wing will still provide a net gain in downforce compared to more conventional designs.

Or not. I dunno.

This could very well explain why Red Bull uses a monkey seat to help drive the diffuser instead of the rear wing. If they feel their rear wing is good enough on its own, they get the flexibility to augment something else instead. That's just a guess, though.

Thoughts?

Also diggin' the new dihedral-like front wing. I wonder how much wider it gets when it flexes.

http://i.imgur.com/zPGdvOQ.jpg

It could be like you say. There are some things that laed me to think differently:

-we know from user Imanengineer that till last year the main function of the monkey seat was help stabilising the main rw - rbr does not run a monkey seat, but a beam wing slice instead, so may want to stabilise the flow with different tricks

-the slots on the lower side of the wing are very similar to what we have seen in the last year on the front wings - in that case the slot help energise the vortex that runs underneath the wing - I think ther could be something similar going on here

-I think drag reduction is not a priority for thsi years cars in Melbourne (nor sepang)

[bhall]

it could be like you say. There are some things that laed me to think differently

[...]

"monkey seat to help drive the diffuser" = "beam wing slice"



We just referred to it in different ways. (I like yours better.)

That it's not installed to assist boundary layer flow on the underside of the rear wing, as monkey seats tend to do, suggests the rear wing doesn't need the help. Ergo, the rear wing's AoA isn't that extreme.

That means it can be positioned to help drive the diffuser instead, which is a much more efficient way to create downforce.

Additionally, the orientation of the end plate slots, each positioned adjacent to the surface of the wing, doesn't suggest an intent to energize flow. Rather, it points to a desire to "stall" the wing. Such was the case for Lotus' DDRS in 2012.


RB10 and E20

To energize flow, the slots would need to be positioned more parallel to the boundary layer, just like wing slots.

(Incidentally, it's for that very reason I sometimes think McLaren's F-duct did not function the way we were led to believe. Transfer your idea about the current Red Bull slots to McLaren's F-duct, and see if it results in the same epiphany I had. But, that's neither here nor there...)


"My, what a steep angle of attack you developed!"

So, yeah, that's why I'm more inclined think Red Bull's end plate slots serve to increase local pressure at the wing tips instead. With added pressure on top of the wing due to the lack of "normal" end plate slots, it's vital to minimize the pressure differential at the wing tips in order to reduce the strength of the vortices they shed.


A larger slot-gap helps, too.

Broadly speaking, a vortex occurs wherever two streams flowing in the same direction, but at different pressures, meet. High-pressure air is literally pulled into the low-pressure stream, and then it's pulled right back into the high-pressure stream, and then it's pulled yet again into the low-pressure stream....and so on and so forth until the pressures equalize, dissipating the vortex. That's the "tumbling" or swirling action we witness when we can actually see them.



The bigger the pressure differential between the streams, the stronger the vortex it creates. The stronger the vortex created, the bigger the (induced) drag penalty, and the longer it will take to equalize. The longer it takes to equalize, the bigger the (far-field) drag penalty imposed.

If you "stall" a portion of the underside of a wing, then by definition you've raised local pressure, which amounts to a reduction in the pressure differential between that area and its higher pressure counterpart. The result: a little bit less downforce, but significantly weakened vortices for less drag.

And with limited fuel this year, reduced drag means a reduced need to run in a fuel-saving mode. Even a seemingly small reduction can be important, because drag squares with speed.

Oh, and this can be tuned as well. Larger slots will "stall" the wing tips at lower speeds than smaller slots. Their positions can also help determine the degree to which they "stall." Red Bull can customize that response for each track, or at least for each type of track. It's even theoretically possible for the team to tune the wing tips to "stall" at any speed higher than that needed for the fastest corner on a given circuit.

It wouldn't come as a surprise to see this all developed into a full-blown DDRS-type system at some point this season. (That's obviously just speculation, though.)



Sold?

[jagunx51]

Yes, that's what I think regarding the silver "thing". I think the silver material is an exhaust heatshield.

This might be the proof that the exhaust pipes are placed horizontal and low... (the golden heatschield)
They lie below the intercooler. The sidepod air duct is inbetween
http://www.servimg.com/image_preview.ph ... u=14795526

http://www.servimg.com/image_preview.ph ... u=14795526

is this possible (or allowed) to use square exhaust pipe ? so redbull engineers could freely designing the exhaust in less roomy sidepod

[jagunx51]

it could be like you say. There are some things that laed me to think differently

[...]

"monkey seat to help drive the diffuser" = "beam wing slice"

http://i.imgur.com/0ux55eh.jpg

We just referred to it in different ways. (I like yours better.)

....

Sold?

http://www.f1technical.net/forum/viewto ... 15#p491315

[timbo]

Yes, that's what I think regarding the silver "thing". I think the silver material is an exhaust heatshield.

This might be the proof that the exhaust pipes are placed horizontal and low... (the golden heatschield)
They lie below the intercooler. The sidepod air duct is inbetween
http://www.servimg.com/image_preview.ph ... u=14795526

http://www.servimg.com/image_preview.ph ... u=14795526

is this possible (or allowed) to use square exhaust pipe ? so redbull engineers could freely designing the exhaust in less roomy sidepod
http://elezzsteel.com/sites/default/fil ... 0pipe3.gif

The final part of exhaust must be circular.

[Kiril Varbanov]

According to Horner himself:

"90 per cent of the issues are software-related - how the energy recovery system is working with the combustion engine," Horner said. "We're tremendously restricted in the driveability of the car - how the torque is delivered - which obviously affects straightline speeds. I think there is room for an awful lot of improvement, but it's working between the engineers in Milton Keynes and [at Renault's base at] Viry-Chatillon to make sure we get the most out of it."

Horner also estimates that Australia winners Mercedes has a second per lap advantage over the opposition.

"I think Mercedes is definitely extremely quick and I should think they were driving to a pace rather than being stretched," he added. "They've probably got more up their sleeve, so we've got quite a lot of work to do. What's encouraging is compared to the rest of the field, we well exceeded our expectations.

"To be racing McLarens and Ferraris after the pre-season that we've had; by the 20th lap we were into new territory in terms of distance completed by the car. I'm sure they didn't fully extend themselves and it looks like they have at least a second in the pocket."

[bhall]

http://www.f1technical.net/forum/viewto ... 15#p491315

Yeah, I think that's probably the general idea.

It makes more sense, at least to me, when we recognize the device as a "beam wing slice," as shelly put it, because we already know about the functionality of beam wings.

[henra]

The slots will cost a bit of downforce relative to the entirely slot-free end plates the team used throughout winter testing, but not by much, and the drag reduction will make it worthwhile. In the end, I think the wing will still provide a net gain in downforce compared to more conventional designs.
...
Thoughts?

The way they designed them with the increasing upward angle I'm not even sure it will cost much DF.

The low pressure on the outside will not only suck air to the inside of the endplates thereby slightly reducing risk of flow separation on the lower side of the rear wing but also accelerate the airflow on the outside upwards to some extent due to the staggered and angled arrangement of these three slots.
It will also slightly increase upwards mass flow at the exit of the wing compensating at least partially for the slight increase of static pressure on the underside of the wing. (Think Newtonian Lift theory).
The upward flow on the outside of the endplate in combination with the cut-out at the upper side of the endplate would also counter to some extent the rotation of the endplate vortex.

So probably a combination of preventing separation on the lower side of the wing enabling low Monkey Seat to help the central diffuser + slight reduction of induced drag with very little if any DF loss. Surely not a huge gain but looks overall like a neat detail solution.

[bhall]

The slots will cost a bit of downforce relative to the entirely slot-free end plates the team used throughout winter testing, but not by much, and the drag reduction will make it worthwhile. In the end, I think the wing will still provide a net gain in downforce compared to more conventional designs.
...
Thoughts?

The way they designed them with the increasing upward angle I'm not even sure it will cost much DF.

The low pressure on the outside will not only suck air to the inside of the endplates thereby slightly reducing risk of flow separation on the lower side of the rear wing but also accelerate the airflow on the outside upwards to some extent due to the staggered and angled arrangement of these three slots.
It will also slightly increase upwards mass flow at the exit of the wing compensating at least partially for the slight increase of static pressure on the underside of the wing. (Think Newtonian Lift theory).
The upward flow on the outside of the endplate in combination with the cut-out at the upper side of the endplate would also counter to some extent the rotation of the endplate vortex.

So probably a combination of preventing separation on the lower side of the wing enabling low Monkey Seat to help the central diffuser + slight reduction of induced drag with very little if any DF loss. Surely not a huge gain but looks overall like a neat detail solution.

I just don't see any risk for flow separation at all. The AoA on the RB10's rear wing is not as steep as that found on the RB8, for instance, and that wing was fine.


(Ignore the circle and arrow.)

Also, if you look at the orientation of the slots on the outside, it would appear to suggest that air flow is not so much pushed through by high pressure flow outside (blue arrow) as much as its pulled in by the lower pressure between the end plates. Otherwise, you'd expect the indentations leading to the slots to be more horizontally aligned in order to focus a ram-air effect.

The current layout gives the slots a scalable effect based upon pressure under the wing instead of the vehicle's speed. Though the two often correlate, they don't always match.


(Don't ignore the blue arrow.)

When teams want to align air flow outside the end plates to follow air flow from the wings, or to go anywhere really, they generally have to do so with tiny winglets or whatever the hell those things are called.


(There's no arrow here to notice or ignore.)

Without them, air just tends to flow straight across, only joining with air flow from the wings when it comes into direct contact with it.

(I don't know what it is with me and pictures lately.)

[shelly]

To me there is similarity with fornt wings like this:



Also note taht in the slotted endplate version rbr uses the 50mm thickenss loophole to have more than two elements, and that the slots in the endplate match with the slots btw the profiles.
If the intention was to induce stall they would have not used the multielement 50mm trick.

Tis type of slots on the endplate would also be useful in yaw, for better downforce again.

Pushed to an extreme, they could try to have the rw ride its own tip vortex like the fw does for increased downforce - if we would see them aplling a small cutout undernesth the leading edge of the rw to let the vortex better roll on the inside that would be a hint ( but I do not think it likely, I am just dreaming a bit).

As for drag reduction: Mclaren using butterfly suspension, even if they are not as inefficient as they may seem, might tell us that in this beginning of new regs aero development is focused more on downforce than on drag reduction than usual

[bhall]

When I use the word stall, I always put it within quotation marks because F1 wings rarely truly stall; they just lose efficiency. So, for me, that's what "stall" means. It's an old habit I picked up when talking about intentional reductions in efficiency with a macro term most folks can easily understand. Perhaps it's time for me to drop that habit.

If it's led to any confusion here, I apologize.

My idea is that the slots reduce the efficiency of the wing tips in order to reduce the strength of the resultant vortices and thus reduce the drag penalty such vortices impose.

They're basically an effort to achieve this...



...without reducing wing area.

With regard to the effect of yaw on the efficiency of the front wing, I absolutely agree it has a dramatic impact. In fact, I tend to think front wings create peak downforce only in yaw, because that's generally when downforce is needed most. So, it only makes sense for front wing development to follow along those lines.

I think that's clearly demonstrated in current-generation wings whose most-downforce-producing elements are clustered toward the outside, where uninhibited flow (read: no downstream blockages) can only be achieved when the wheel behind it is turned. (The narrower wings this season have reduced the effectiveness of this philosophy.)


RB9

This isn't really possible for rear wings, though, for two reasons. First: the front wing passes through naked air. That is, it passes through air that has not been conditioned in any way by any aerodynamic devices on the car. That means it can take advantage of any change in direction it imparts on that flow. After all, it is precisely that change of direction that results in the ability of the outside edge of the wing to produce more downforce.

In fact, it's only by changing the direction of air flow that any wing can create any downforce at any time, yanno?

Because rear wings never really encounter naked air flow, at least not in abundance, they tend to be optimized to pass through air flow already conditioned by the front wing and other devices to travel straight back.

And second: rear wing designs created to enhance performance in yaw, like whatever the hell that thing was on the back of the RA108, are banned. So are the devices formerly used to condition air flow over it, e.g "Viking horns."


Honda RA108

And really, those devices didn't "enhance" downforce as much as they attempted to mitigate downforce losses in yaw, because, again, rear wings create peak downforce in straight air flow. All other conditions result in lost efficiency.

And think twice about why McLaren might be willing to suffer a slight increase in drag with aerodynamically-shaped suspension members. If that results in increased efficiency from the diffuser, it's a pretty big net gain, because ground-effect downforce is the single-most efficient form of downforce. The more downforce you get from a diffuser, the less you need to get it from wings. That's a pretty big deal in a fuel-limited formula when drag squares with speed, and the power needed to overcome that drag is cubed at the same time.

Sorry if I'm droning on and on and on... Brevity is a virtue I do not possess. (And it appears I've developed a compulsion to illustrate. Great, just what I needed.)

[trinidefender]

When I use the word stall, I always put it within quotation marks because F1 wings rarely truly stall; they just lose efficiency. So, for me, that's what "stall" means. It's an old habit I picked up when talking about intentional reductions in efficiency with a macro term most folks can easily understand. Perhaps it's time for me to drop that habit.

If it's led to any confusion here, I apologize.

My idea is that the slots reduce the efficiency of the wing tips in order to reduce the strength of the resultant vortices and thus reduce the drag penalty such vortices impose.

They're basically an effort to achieve this...

http://i.imgur.com/7o24LFT.jpg

...without reducing wing area.

With regard to the effect of yaw on the efficiency of the front wing, I absolutely agree it has a dramatic impact. In fact, I tend to think front wings create peak downforce only in yaw, because that's generally when downforce is needed most. So, it only makes sense for front wing development to follow along those lines.

I think that's clearly demonstrated in current-generation wings whose most-downforce-producing elements are clustered toward the outside, where uninhibited flow (read: no downstream blockages) can only be achieved when the wheel behind it is turned. (The narrower wings this season have reduced the effectiveness of this philosophy.)

http://i.imgur.com/a9xadJw.jpg
RB9

This isn't really possible for rear wings, though, for two reasons. First: the front wing passes through naked air. That is, it passes through air that has not been conditioned in any way by any aerodynamic devices on the car. That means it can take advantage of any change in direction it imparts on that flow. After all, it is precisely that change of direction that results in the ability of the outside edge of the wing to produce more downforce.

In fact, it's only by changing the direction of air flow that any wing can create any downforce at any time, yanno?

Because rear wings never really encounter naked air flow, at least not in abundance, they tend to be optimized to pass through air flow already conditioned by the front wing and other devices to travel straight back.

And second: rear wing designs created to enhance performance in yaw, like whatever the hell that thing was on the back of the RA108, are banned. So are the devices formerly used to condition air flow over it, e.g "Viking horns."

http://i.imgur.com/01dwsR1.jpg
Honda RA108

And really, those devices didn't "enhance" downforce as much as they attempted to mitigate downforce losses in yaw, because, again, rear wings create peak downforce in straight air flow. All other conditions result in lost efficiency.

And think twice about why McLaren might be willing to suffer a slight increase in drag with aerodynamically-shaped suspension members. If that results in increased efficiency from the diffuser, it's a pretty big net gain, because ground-effect downforce is the single-most efficient form of downforce. The more downforce you get from a diffuser, the less you need to get it from wings. That's a pretty big deal in a fuel-limited formula when drag squares with speed, and the power needed to overcome that drag is cubed at the same time.

Sorry if I'm droning on and on and on... Brevity is a virtue I do not possess. (And it appears I've developed a compulsion to illustrate. Great, just what I needed.)

Go and do some reading on wing vertical wing tips. Do not use the word stall as it is highly misleading regardless of your intentions and in an aerodynamics term completely incorrect.

By higher pressure airflow moving through the slots, below and behind the rear wing, to the lower pressure side on the underside of the wing you decrease the pressure differential between each side of the endplate. By reducing the pressure differential you reduce the size and strength of any vortices that are formed. This will cause a reduction in drag of designed correctly. This is well understood by most people

The part that may confuse some people is that while it reduces drag it may have very small to nil to even positive effect on downforce. I am not saying it will but that in some scenarios it can. Allow me to explain. At the edge of any wing there will be a vortex formed as a result of a pressure differential between two sides of the wing, this is an understood concept. Any wing surface area that lies within this wingtip vortex effectively does not act like a wing anymore and produces no lift or in this case downforce. You are reducing the span of your effective wing. This is one of the reasons why gliders and other aircraft where lift/drag ratio is paramount use high aspect ratio wings. Refer to picture below. They are maximising the effective lifting surface of their wing. Back to F1 now, the use of of the endplate devices such as the slots both above and below the wing serve to reduce the size of the tip vortices and regain lost wingspan henceforth creating more downforce. Both the slots above and below do the same job, they just achieve it in slightly different ways.

If anybody wants a different explanation PM me and I'll be happy to oblige.