McLaren MP4-28 Mercedes

[stefan_]

We're not going anywhere because you are getting heated up. I'm not bashing McLaren or something like that or pretend to be a forum engineer like others, you are getting it the wrong way. I didn't say that the FW is the sole solution of gains over a lap, but that McLaren's FW design is rather simple (yes, compared to others) and maybe it's an area of improvement.

[beelsebob]

We're not going anywhere because you are getting heated up. I'm not bashing McLaren or something like that or pretend to be a forum engineer like others, you are getting it the wrong way. I didn't say that the FW is the sole solution of gains over a lap, but that McLaren's FW design is rather simple (yes, compared to others) and maybe it's an area of improvement.

Okay, and my assertion is that on the list of areas of improvement, it's almost certainly extremely low on McLaren's list of priorities, for several reasons:
1) They are clearly happy with the overall design, as they have been using it on several championship challenging cars
2) They have (relatively) recently reduced its downforce production (by for example removing the snow plow, and then the cascades), and in doing so chose not to significantly change its shape to provide better airflow to the rear of the car – that again suggests that they are happy with the airflow it's providing to the rest of the car
3) They have already asserted that they are struggling with diffuser detachment and tyre squirt issues.
4) The drivers have complained about stiff suspension issues making the car unpredictable.

Basically, they have highlighted the areas of the car they feel need improvement, and repeatedly passed the front wing over for improvement. While I'm sure there's room for improvement in the wing (there always will be), I have no reason to believe that adding slots to it, is what's needed, and good reason to believe that McLaren have things far higher on their priority list than their front wing.

[stefan_]

I agree with that, I am sure that they know what they are doing and they are considering every option available to improve the car.

[trinidefender]

Ok coming from a commercial pilot who has done up a lot of study on general aerodynamics. One large wing whether it be to produce lift (as on a plane) or downforce (as on a car) has a higher lift to drag ratio than many small wings. Meaning it produces more of a vertical force compared to the amount of drag it produces. F1 cars however have a very small space to work with which means that they have to use wings with high angle of attack. When your angle of attack becomes to high you get airflow separation off of the outer curve of the wing and the wing stalls. While this reduces drag it also almost completely reduces all downforce. There are two methods to stop the wing from stalling. One; lower the angle of attack but make the wing thicker. This increases airspeed over the lower portion (on a downforce producing wing), reduces pressure underneath the wing and creates more downforce. This solution is great for slow speed work (look on many slow propellor planes and you will see how thick the wing is), however as speed increases, the wings induced drag increases very quickly. Put simply, induced drag is the drag created when the high and low pressure air from each side of a wing mix. Option number two is to spilt the wing up into more than one section with airflow flowing from one section to another subsequently reducing the apparent angle of attack on every wing behind the first one. This is the approach that seems to be favoured in F1. However, for every wing section you add you disturb the airflow more and more creating more turbulence in the air stream which the car has to deal with further back on the car. Therefore by McLaren running a FW with fewer but larger (and possibly thicker) wing sections they may be attempting to sacrifice a bit of downforce in exchange for having cleaner airflow to the rest of the car.

A wing can do three things. One, it can create a force perpendicular to the apparent angle of attack of the wing. Two, it can change the direction of the airflow. Note, affect number two will always occur when affect one happens. Or three, it can attempt the smooth out dirty airflow by increasing pressure in a certain area and changing the airflows direction.

Now assuming you are not driving in somebody's wake then the FW will always be sitting in clean airflow, there, in theory, it should be the easiest to design with CFD computers. That is one thing that leads me to believe they are happy with their front wing.

[techF1LES]

A bit late to the party, but anyway, this front wing talk needs to be pointed in the right direction. Personally, I agree with beelsebob. Different design philosophy doesn't automatically mean worse... However, I'm not an aerodynamicist, so let me quote experienced aerodynamicist from unnamed Formula 1 team.

The number of elements a front wing has does not define how much downforce it creates or how 'good' or 'bad' it is. In fact, a unstalled, healthy wing with more slot gaps, will produce more loss than one with less slot gaps that is equally healthy as every slot gap causing thickening of the the overall boundary layer (this is a simplification, in practice they're unlikely to be equally healthy).

You generally only add slots once you're attempting to do more work with an element than it's capable of doing without stalling. The whole percentage stall thing is a bit of a red herring. If the last element but one stalls before the slot gap, it might end up being less efficient than a single element that stalls only towards the end of it's element.

At the end of the day, both philosophies (McLaren vs the rest of the world) have their advantages and downsides. If you read between the lines carefully, you'll come to a conclusion that the main difference is in the way aero devices downstream work the airflow outgoing from front wing's trailing edges.

Again, more elements doesn't always mean more downforce. So called 'multi-element' front wings are often misinterpreted as being more efficient in generating downforce, but in fact it's delusion. The whole point about multiple elements at the outboard edges of the front wing has more to do with flow management in yaw.

If you think about what yaw does, it basically introduces a more 'difficult' onset flow condition. Teams usually develop their wing for this, and hence the number of elements will be designed for this condition, with it being 'overstable' in a straight condition. It's true that this condition may require more elements to stay healthy. The outboard of the wing/endplate tends to be the critical region so there tend to be more slots in this region.

...sorry, I know this is Macca topic

[trinidefender]

A bit late to the party, but anyway, this front wing talk needs to be pointed in the right direction. Personally, I agree with beelsebob. Different design philosophy doesn't automatically mean worse... However, I'm not an aerodynamicist, so let me quote experienced aerodynamicist from unnamed Formula 1 team.

The number of elements a front wing has does not define how much downforce it creates or how 'good' or 'bad' it is. In fact, a unstalled, healthy wing with more slot gaps, will produce more loss than one with less slot gaps that is equally healthy as every slot gap causing thickening of the the overall boundary layer (this is a simplification, in practice they're unlikely to be equally healthy).

You generally only add slots once you're attempting to do more work with an element than it's capable of doing without stalling. The whole percentage stall thing is a bit of a red herring. If the last element but one stalls before the slot gap, it might end up being less efficient than a single element that stalls only towards the end of it's element.

At the end of the day, both philosophies (McLaren vs the rest of the world) have their advantages and downsides. If you read between the lines carefully, you'll come to a conclusion that the main difference is in the way aero devices downstream work the airflow outgoing from front wing's trailing edges.

Again, more elements doesn't always mean more downforce. So called 'multi-element' front wings are often misinterpreted as being more efficient in generating downforce, but in fact it's delusion. The whole point about multiple elements at the outboard edges of the front wing has more to do with flow management in yaw.

If you think about what yaw does, it basically introduces a more 'difficult' onset flow condition. Teams usually develop their wing for this, and hence the number of elements will be designed for this condition, with it being 'overstable' in a straight condition. It's true that this condition may require more elements to stay healthy. The outboard of the wing/endplate tends to be the critical region so there tend to be more slots in this region.

https://pbs.twimg.com/media/BIXU1NWCIAAk9E4.png:large
...sorry, I know this is Macca topic

TechF1LES you pretty much repeated everything I just said you do realise that. The only reason for adding more slots is to allow airflow to stay attached to the wing.

[wesley123]

Had you considered the fact that McLaren are not tweaking it so much as the other top teams may be a strong indication that McLaren are much more happy with their design than the other top teams are with theirs.

So why did every team step away from the McLaren like around 2010-2011?

With that in mind… Why is everyone so focused on the idea that McLaren should switch to the other teams' philosophy?

Because it is an easy pick, it is something visually different compared to the rest of the field. While it might or might not be the cause of the problems, I do believe McLaren are behind in Front wing design. Everyone evolved their wings from something with 2 large flaps to a design that has to fixed planes, with a more 'diffuser like' inner sections and a single flap(or more recently two smaller flaps).

Also, a trend in front wing design already started in 2009 were the outer tips bend down towards the footplate, creating an 'endplateless' design. McLaren finally incorporated such design at the 2012 US GP, that is 3 years after the first team switched to such design and almost a year later than every other team.

And to take a look at how front wings evolved(all the pics are from 2010 launch and then 2013 launch);
Red Bull;

Red Bull was pretty much the first team to follow the rounded outer edges of the wing/endplate. Their wing evolved into this;


Ferrari;

Their wing evolved into something very similar that we saw on the red bull;


Mercedes;

It evolved into this;


Force India;

it evolved into this, something similar to Red Bull;


Sauber;

It evolved into this;


Renault/Lotus;

Now they run this;


The rest of the teams now all run a similar philosophy regarding Front Wings, except for McLaren;

And that evolved into this;


As you can see, every team evolved from something into a similar solution. All the rounded edges, the single(or split) flap setup, all the high cambered/diffuser like inner section, all using the wing tips in a similar way. McLaren on the other hand stayed pretty much the same, a 2 large flap design, all flaps are the same length. It took them ages to copy the 'endplateless' outer edge design.

One could say that the McLaren then is super good, and was already in 2010, but then one would expect a similar design would be copied(Although FI did in 2011 on a few occasions, but decided to stick with their own design). So that leads me to believe that the McLAren wing is indeed behind on other designs.

But well, who change it? They would run it for max 17 races because then there will be new rules, it's a bit of a waste of time. Also why put that effort into developing a wing in a year that is pretty much already lost? if you ask me, the biggest we will see is that they get rid of the flaws of the MP4-28 and 'learn' the pull rod front, and apply that to 2014.

So even though their front wing is somewhat behind in design, there is no point in updating something that will only be ran in a year that is already lost, better to then keep with what you know, and fix the flaws, and apply these lessons learnt to 2014.

[turbof1]

I also hear things like McLaren following their own philosophy. Ehmm? What? Take a good look at this years car. It follows the mainstream philosophy (well, except for the FW of course...). Last year you could still argue that; this year it's obvious that they went high nose just like everybody else. Completely same philosophy. Yet they keep the old philosophy FW.

[Pup]

Hmm.

Well, as I've said many times before, it's always safe to bet on a new front wing because they're probably one of the most often tweaked bits on the car. That is, they'll have a new wing for Barcelona, whether they need one or not!

But I also think it's correct that the tweaks we'll see to the wing in Barcelona will indeed be related to The Fix, as opposed to just standard ho hum development, even though I don't think the wing is in itself wrong, or too simple. The fact that McLaren haven't touched it, even through testing and despite bringing out a whole raft of complex bits for China, tells us that, in general, the wing doing what it's supposed to. It's good enough, though I'm sure that they've put off planned developments of it just to keep from effing with their temporary fixes on the tail end.

What we've been told, from those who should know better than us, is that the diffuser isn't working properly. Or rather that it's working intermittently, unpredictably. We've also been told that it was a miscalculation in the dynamics of the rear tires which is at the heart of the problem.

So if we're to believe that - and I can't see a single reason not to - then the question isn't what bit is at fault, but rather what bit, or bits, can be changed to fix it. Again, as I've said before, just because a diffuser is stalling, it doesn't mean that the design of the diffuser is bad. In fact it's likely that no individual piece is bad. It just means that the diffuser is stalling. The aero, it doesn't work. You might fix it with a wing, or a winglet, or a floor, or splitter, or some combination - or their might be more than one way to fix it even. So, it's just the aero - it works, or it don't works.

My guess has been and remains that since there was a fundamental calculation on the tail end of the aero which was wrong, then when they recalculate everything the resulting redesign will affect not only the diffuser, but pretty much everything upstream of it. So yeah, I think we'll see a new front wing; but no, I doubt if the philosophy behind what it does and why it is designed the way it is will change. I mean, it's possible, but that's not where my bet is placed.

The good news is that everyone who's laid claim to some bit of the car being bad will surely be rewarded in Barcelona. There should be like three pages of "As I Posted Weeks Ago", so it'll be just a grand time here. I'm trying to get mine in now to avoid the rush .

As for those multi-element thingamajiggers, I'm tempted to post the twenty-blade razor video again. But it all comes down to a single element producing less drag for a given amount of downforce, and therefore being preferred; however, a single element will stall easier than a multi element. So, McLaren's element-starved wing could mean either of two things, and none of us can possibly know which of those two it is - a) the rear is producing so little downforce that the front wing doesn't need to be cranked to balance the car, therefore making fewer elements more efficient; or b) McLaren have simply designed an ass kicking front wing that doesn't stall as quickly and therefore doesn't need a multitude of elements.

And also, a lot of the little bits on the front wing are just there to tweak the airflow, and being a new design, which they've avoided developing for the moment, it's only natural that it looks a bit simple. As I've said before, the wing may be underdeveloped for this stage in the game, even if it ain't broke.

[Pilatus]

I don't think that FW alone is a problem.
Like beelsebob said, FW worked great on MP4-27.


I think that problem lies in lack of rear DF.
Too aggresively shaped coke bottle, not so perfectly exhaust design, exhaust plume not reaching diffuser in the way it should be...in the end - diffuser out of it's working envelope.

With lack of rear DF, comes disbalance between front and rear.
Quickest and simplest way to fix that disbalance - to shave some front DF. Removing the most draggy elements.
Similar story to Mercedes last year.


Next stop - maximizing the rear. And i think that recently changes(slimmer sidepods) are targeted just on that.
Changing the airflow around most problematic areas - coke bottle, exhaust, diffuser.

And my guess is that sidepods/exhaust/coke bottle will face even bigger changes before Spain.
And then we'll maybe see FW with it's elements brought back, like in Australia.

[Jackles-UK]

From what i've heard from various engineers less than half of the FW design is designed to be actually used for downforce generation these days, the biggest job it has is redirecting the air from the front to the back of the car with as little obstruction as possible. This has bore rise to both endplate-less FWs as well as multi-element designs to steer air around the tyres and over/around sidepods. I don't think that the Mclaren one is low in terms of downforce creation (if that were the case then i'd expect to see the snowplough re-appear rather than the removal of the cascades) but surely they must be lacking something elsewhere. Newey has also said that F1 cars, even since the days of the pre '09 regulation slim FWs, have had plenty of front end but the rear was always the problem (traction as well as rear grip & stability) - balancing the two being the most difficult skill of course.

With that in mind surely even the most ardent 3 element fan can't deny that the wings on offer from Ferrari, Merc, RBR etc look far more capable of sending larger volumes air where they want it? I'm not at all saying that "extra elements just for extra elements sake" is the way to go but would a more stable airflow off the FW to other parts of the car not help figure out their funny handling characteristics?

[trinidefender]

From what i've heard from various engineers less than half of the FW design is designed to be actually used for downforce generation these days, the biggest job it has is redirecting the air from the front to the back of the car with as little obstruction as possible. This has bore rise to both endplate-less FWs as well as multi-element designs to steer air around the tyres and over/around sidepods. I don't think that the Mclaren one is low in terms of downforce creation (if that were the case then i'd expect to see the snowplough re-appear rather than the removal of the cascades) but surely they must be lacking something elsewhere. Newey has also said that F1 cars, even since the days of the pre '09 regulation slim FWs, have had plenty of front end but the rear was always the problem (traction as well as rear grip & stability) - balancing the two being the most difficult skill of course.

With that in mind surely even the most ardent 3 element fan can't deny that the wings on offer from Ferrari, Merc, RBR etc look far more capable of sending larger volumes air where they want it? I'm not at all saying that "extra elements just for extra elements sake" is the way to go but would a more stable airflow off the FW to other parts of the car not help figure out their funny handling characteristics?

Therein lies your problem, while adding more elements to the front wing may help to redirect airflow better it also creates more turbulence off of the back of the wing which I think McLaren is trying to avoid. More turbulence which the rest of the car has to work with. This isn't to much of a problem if they are trying to run a low downforce car, however wings work very poorly in turbulent air. Therefore in my opinion if McLaren sacrifices a bit of front downforce they can then use the cleaner flowing air off of the front wing to help the rear wing and diffuser create more downforce. This is one reason why I think McLaren has a simple front wing currently, because they already have low rear DF, if they add more elements to the front wing then the rear wing has more turbulent air to deal with reducing rear DF even further.

[mclaren_mircea]

What do you think, in race trim was Mp4-28 faster than W04?

[hakan439]

For the experts on the forum, Who was saying that last years car was much faster then this years car. How was mp4-27 fastest car last year with this undeveloped, basic fw

[turbof1]

For the experts on the forum, Who was saying that last years car was much faster then this years car. How was mp4-27 fastest car last year with this undeveloped, basic fw

Simple: mclaren produced the most downforce at the back because they were the best at redirecting the exhaust plume to where they wanted it. Their FW was more then enough to produce the necessary front DF.

The problem isn't that isn't working. The FW is more then good enough for what it does. IMO, the problem lies within what it is designed for. It is more designed for efficient downforce creation and less for airflow control towards the rear.