McLaren MP4-28 Mercedes

[beelsebob]

I made an edit to my previous post. Check that too.

I am not sure if they are running more AoA. Possibly the area in front of the wheels has a higher AoA. In the end, they can't run more front DF then the rear has.

It does add up with what you say. If most of the front DF is produced just in front of the wheels, then that surface of the FW produces the most turbulent air. because the wheel would have made that air turbulent anyway, it's not a big disadvantage.

It absolutely adds up. McLaren are struggling to produce rear downforce. As such, they're both choosing to produce less front downforce, and to provide better airflow to the rear of the car while developing the rear as much as they possibly can.

Add this to the fact that it may well be that McLaren, with a few more years experience of running front wings of this style, understand how to get the air to turn the corner a bit more, and keep it attached to a very slightly higher AoA second or third plane, and it makes perfect sense.

[wesley123]

Suppose (simplification incoming) for a second that air detaches from a wing when the AoA is more than 20°. Suppose that the downforce production of a segment of wing is linearly proportional to the length of that element, and to it's AoA assuming air stays attached. Both aren't far from the truth, but rather dramatic simplifications. Finally, lets assume that a wing element turns the airflow coming off it by half it's AoA, again, a simplification, but not too far from the truth.

In all cases we will assume the wing is unit length.

In case 1, we have a 2 element wing, the first element with an AoA of 10°, the second with an AoA of 25° to the original airflow. The air stays attached to both, the first element produces 0.5 (due to length) * 0.1 (due to AoA) + 0.5 * 0.2 = 0.15 units of downforce.

In case 2, we have a 2 element wing, the first element with an AoA of 10°, the second with an AoA of 30°. The air detaches from the second (we'll assume it stays attached to the first, though this is unlikely now), we now get 0.5 * 0.1 = 0.05 units of downforce.

In case 3, we have a 3 element wing. The first element with an AoA of 10°, the second with an AoA of 25°, the third with an AoA of 45°. We now get 0.33 * 0.1 + 0.33 * 0.2 + 0.33 * 0.2 = 0.165.

Obviously these are dramatic simplifications, but the point remains, while each element of the multi element wing produces less downforce, the downforce production of the wing overall exceeds what is possible from a wing with fewer elements.

This is why you saw teams wanting to design 3 or more element rear wings before they were banned. They didn't care about the turbulence produced behind the rear wing, they only cared about the fact that they could get more L/D that way. If the teams thought that they could get better L/D with fewer elements, then the 2010 rear wings would have involved only 1 element. Similarly, the pre-2-element-rule wings would have had only 1 element.

Sure a 4 plane wing has more peak downforce than a 3 plane wing. It is because a 4 plane wing can be pushed to higher AoA(ofc there is a point where more planes dont equal more peak df). But a thing here is that they arent pushed beyond a certain level of AoA where a 3 plane wing would stall. The 4 plane wings teams run dont run more AoA than they do on 3 plane wings, and in such a situation, a 3 plane wing would generate more downforce, while on the other hand the 4 plane wing is less sensitive.
So on current Wings imo it is more a job of creating a less sensitive wing(which would enhance driveability) and sending air downstream than actually produce as much df as possible.

The wings have become much more about improving airflow downstream than about generating as much downforce as possible. Teams put a lot of effort in that, and this came to the utilisation of the wing tip vortices, the slots in the outer section etc. etc.

[beelsebob]

Sure a 4 plane wing has more peak downforce than a 3 plane wing. It is because a 4 plane wing can be pushed to higher AoA(ofc there is a point where more planes dont equal more peak df). But a thing here is that they arent pushed beyond a certain level of AoA where a 3 plane wing would stall. The 4 plane wings teams run dont run more AoA than they do on 3 plane wings,

And here I think we've hit the core of where we're disagreeing. I believe that the teams that are running multi element wings are running a higher AoA. Especially in front of the front wheels.

[turbof1]

Possibly it is more prone to stalling so close to the wheels, lowering the point of stalling to a lower AoA. Very difficult to tell; I can definitely see the slots between the elements used for flow redirection, though if that is the case I do not know. We need an aero expert on that one (next question on "The Racer's Edge").

I wonder if they had these same discussions at mclaren too. And if they took longer then a full page to get to the core of disagreement.

[trinidefender]

Ok again. People are making claims about this or that yet nobody here has stated where they are getting their information from. Me personally, when I posted earlier I stated I was a commercial pilot who has done a lot of study of aerodynamics. Before people say things can they at least establish on what basis they are making the claims. As in if they have a job that involves aerodynamics etc. people are mentioning AoA. However nobody here except me has mentioned the real term they should be talking about which is apparent angle of attack.

A multi element wing WHERE THE AIRFLOW IS FLOWING FROM ONE ELEMENT TO ANOTHER vs another multi element where each element is stacked will have two different sets of operating characteristics. In the first instance where all the airflow coming off of one element goes onto the second has the characteristics of having a wing that is very good at resisting stall conditions and maintaining airflow over each element. An example of this are the flaps on a 747-400. They are called fowler double slotted flaps. The problem with this arrangement is that as speed increases drag increases very quickly because while the apparent angle of attack to the airflow stays relatively the same over each element, the angle of attack of the wing relative to the car and therefore the force of the wing is directed as much back as it is down creating more drag. If I have lost anybody then let me know. The second type of multi element wing has the elements stacked on top of each other. Similar to a bi and tri plane aircraft. In this situation on an aircraft because the wings are so far apart there isn't to much interference between each wing. However there is still some interference. The characteristics of this type of multi element wing is that you can get more surface area into a smaller package. Looking at most teams FW's it seems that there is some combination of the two with a bias towards the airflow going from on wing to another.

I am not trying to explain why McLaren did what they did. I am trying to educate people on aerodynamics to hopefully clear up some of useless and plain wrong things being said.

[ringo]

All this talk on front wings..
Boy i hope a new wing solves the problem, because it would be a lot of wasted energy typing all that wing stuff.

The front wing isnt the problem. It's too simplistic to say a wing change will solve Mclaren's problem which is quite complex.
It's not a matter of the car just not having enough downforce.
If this wing is a problem, then the 2012 car would not have been so fast last year. All teams kept wings similar to last year, so Mclaren's 2012 wing can be compared to the 2013 wings of other cars. The 2012 wing worked pretty well.
So i don't see how the front wing is now to be blamed, and how it is viewed as being prehistoric.

Mclaren has a chassis problem. It's all in their mounting points on both chassis and gear box. That's why they will have a headache fixing it.
They would kill to have a front wing problem. They will thank the racing gods if all they had to do was a front wing update.

[beelsebob]

Ok again. People are making claims about this or that yet nobody here has stated where they are getting their information from. Me personally, when I posted earlier I stated I was a commercial pilot who has done a lot of study of aerodynamics. Before people say things can they at least establish on what basis they are making the claims. As in if they have a job that involves aerodynamics etc. people are mentioning AoA. However nobody here except me has mentioned the real term they should be talking about which is apparent angle of attack.

1) Actually, while I didn't cite the term by name, you'll see from my (extremely rough) calculations that I was taking that into account.
2) The assertion that you have to say how you were educated is just plain bullshit – that's called an argument to authority, and is a logical fallacy. What makes things valid arguments or not is whether they are correct or not. If something is incorrect, you should state why, rather than stating "I have done aero"… Thankfully, you go on to do exactly that

A multi element wing WHERE THE AIRFLOW IS FLOWING FROM ONE ELEMENT TO ANOTHER vs another multi element where each element is stacked will have two different sets of operating characteristics. In the first instance where all the airflow coming off of one element goes onto the second has the characteristics of having a wing that is very good at resisting stall conditions and maintaining airflow over each element. An example of this are the flaps on a 747-400. They are called fowler double slotted flaps. The problem with this arrangement is that as speed increases drag increases very quickly because while the apparent angle of attack to the airflow stays relatively the same over each element, the angle of attack of the wing relative to the car and therefore the force of the wing is directed as much back as it is down creating more drag.

Good, I'm glad we agree on the characteristics of the multi element wings being discussed here.

If I have lost anybody then let me know. The second type of multi element wing has the elements stacked on top of each other. Similar to a bi and tri plane aircraft. In this situation on an aircraft because the wings are so far apart there isn't to much interference between each wing. However there is still some interference. The characteristics of this type of multi element wing is that you can get more surface area into a smaller package. Looking at most teams FW's it seems that there is some combination of the two with a bias towards the airflow going from on wing to another.

Interesting, but not very relevant to the discussion, as the difference between the wings being discussed is how the teams divide up the main wing into 2 to 6 elements, not how the cascades above the wing are arranged (which, while subtly different, is pretty much the same between all of the teams).

All this talk on front wings..
Boy i hope a new wing solves the problem, because it would be a lot of wasted energy typing all that wing stuff.

The front wing isnt the problem. It's too simplistic to say a wing change will solve Mclaren's problem which is quite complex.
It's not a matter of the car just not having enough downforce.
If this wing is a problem, then the 2012 car would not have been so fast last year. All teams kept wings similar to last year, so Mclaren's 2012 wing can be compared to the 2013 wings of other cars. The 2012 wing worked pretty well.
So i don't see how the front wing is now to be blamed, and how it is viewed as being prehistoric.

Mclaren has a chassis problem. It's all in their mounting points on both chassis and gear box. That's why they will have a headache fixing it.
They would kill to have a front wing problem. They will thank the racing gods if all they had to do was a front wing update.

I'm glad there's someone out there who agrees that the solution is not "zomg, they've not got 5 slots in their front wing".

[FrukostScones]

MP4-28 update list for Montmelo / BCN according to AMUS:


New front wing, new bargeboards/turning vanes, new side pods, new exhausts, new floor (diff?), new engine cover and new rear wing.

Nose stays high, front pull-rod stays. All acc. to M. Whitmarsh

http://www.auto-motor-und-sport.de/form ... 21029.html

if it was posted before, sry!

[trinidefender]

2) The assertion that you have to say how you were educated is just plain bullshit – that's called an argument to authority, and is a logical fallacy. What makes things valid arguments or not is whether they are correct or not. If something is incorrect, you should state why, rather than stating "I have done aero"… Thankfully, you go on to do exactly that

I am not claiming that I know everything I am simply asking that people provide some sort of insight into where they are making their assumptions from. Is that to much to ask. If anybody wishes to probe my knowledge further then I can point you in the direction of many books and articles written on aerodynamics. While many of these are biased toward flight, the physics do not change and the same rules apply whether you are trying to produce lift or downforce.

You also mentioned that the second type of multi element wing I spoke about was irrelevant. This isn't completely true because if you look at the front wings of many teams you'll see that many of the elements overlap each other rather than being behind each other which changes the way how the slot works and introduces some characteristics of the second type of multi element wing.

In a true slotted multi element wing the airflow from the top of a downforce wing would flow down behind the wing and flow onto the low pressure side (the underside) of the element behind it. These wings however are mostly oriented so that the airflow stays constant over each wing. Sorry that is not a very good explanation. When I am less tired I will try to think of a better way to explain what I mean.

[trinidefender]

And beelsebob. I am not doubting you or others. Just simply asking where you and others get their knowledge from. Because I hear people making very bold claims about all sorts of things and not backing up their claims with anything other than "in my opinion." I want to know where they get the knowledge to form these opinions. If you haven't noticed I am for the most part staying out of these arguments. I have been reading this blog for a while now and it has only recently frustrated me enough that I have posted some things about basic aerodynamics in hopes of clearing up some blatantly wrong ideas about how wings work etc.

Oh and for everybody here reading this. If you want to learn some things about wings. Read up about NACA airfoils. Then you'll realise how much more complicated it is than. "More elements means more downforce"

[beelsebob]

2) The assertion that you have to say how you were educated is just plain bullshit – that's called an argument to authority, and is a logical fallacy. What makes things valid arguments or not is whether they are correct or not. If something is incorrect, you should state why, rather than stating "I have done aero"… Thankfully, you go on to do exactly that

I am not claiming that I know everything I am simply asking that people provide some sort of insight into where they are making their assumptions from. Is that to much to ask. If anybody wishes to probe my knowledge further then I can point you in the direction of many books and articles written on aerodynamics. While many of these are biased toward flight, the physics do not change and the same rules apply whether you are trying to produce lift or downforce.

I did not assert that you needed to back up where you had learned about aero – again, my assertion was that it does not matter where something is learnt, it matters whether it is correct or not. As you are so insistent, I have no formal education in aerodynamics, only what I pick up by reading papers.

You also mentioned that the second type of multi element wing I spoke about was irrelevant. This isn't completely true because if you look at the front wings of many teams you'll see that many of the elements overlap each other rather than being behind each other which changes the way how the slot works and introduces some characteristics of the second type of multi element wing.

Fair point, but we are getting into fairly subtle effects here, which, while they obviously matter, are deffinately not something we can pick up on without CFD modelling or a wind tunnel, so they're still rather irrelevant for this forum. At least, other than those who have experience working with CFD packages, and accurate enough models of the wings to produce interesting results.

With all that in mind, I don't really see much point in violently agreeing with you further. You and I seem to both be saying that the wings with more elements allow the wing to maintain a higher AoA, and a lower apparent AoA at the same time. This causes more drag, more turbulence, and, when the wing is cranked up to very high AoAs more downforce as a general rule. McLaren's design meanwhile (again, as a gross generalisation) can not be cranked up to as high an absolute AoA, but produces less drag, less turbulence, and likely less downforce too. Correct me if I've misunderstood anything you've said here.

[PlatinumZealot]

MP4-28 update list for Montmelo / BCN according to AMUS:


New front wing, new bargeboards/turning vanes, new side pods, new exhausts, new floor (diff?), new engine cover and new rear wing.

Nose stays high, front pull-rod stays. All acc. to M. Whitmarsh

http://www.auto-motor-und-sport.de/form ... 21029.html

if it was posted before, sry!

that's a whole new car!

Lets see if the problem is solved.

[beelsebob]

MP4-28 update list for Montmelo / BCN according to AMUS:


New front wing, new bargeboards/turning vanes, new side pods, new exhausts, new floor (diff?), new engine cover and new rear wing.

Nose stays high, front pull-rod stays. All acc. to M. Whitmarsh

http://www.auto-motor-und-sport.de/form ... 21029.html

if it was posted before, sry!

that's a whole new car!

Lets see if the problem is solved.

It always boggles me that people think that the surface of the car is the whole car.

[Pup]

if it was posted before, sry!

'twas.

that's a whole new car!

That, too.

Ok coming from a commercial pilot who has done up a lot of study on general aerodynamics, etc...

And all that. Several times. Which made me chuckle at...

you pretty much repeated everything I just said you do realise that.

Which nonetheless was true. Such is how the forum do. No one bothers to read more than three posts down the page before throwing in their three cents. And I don't blame them. I mean, who wants to read all that?

Which I'm going to guess has also been said. Several times.

[Racer X]

The only things not being updated is the chassis (because you cant) and the front pullrod suspension. Aside from that its full updates.

Im assuming since they didnt use the windtunnel for all the little fixes we saw on the McLaren in the last races that these updates have been worked on using both the simulator and wind tunnel.

Hope they work.

Ill admit to being optimistic since the last updates all showed improvements each race.