McLaren MP4-28 Mercedes

[beelsebob]

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.

Except that we well know that multi element front wings are for quite the reverse of this purpose

More elements == more downforce, more drag, and more turbulent air flow behind them
Fewer elements == less downforce, less drag, and cleaner air flow behind them.

[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.

Except that we well know that multi element front wings are for quite the reverse of this purpose

More elements == more downforce, more drag, and more turbulent air flow behind them
Fewer elements == less downforce, less drag, and cleaner air flow behind them.

Most teams use the extra elements for flow control towards the back. Yes, they create turbulent ariflow and more drag, but also better airflow control and redirection. It is always a compromise. Hence why I said "efficient downforce creation" in the case of the mclaren situation, which most certainly has a better L/D.

[beelsebob]

Except that we well know that multi element front wings are for quite the reverse of this purpose

More elements == more downforce, more drag, and more turbulent air flow behind them
Fewer elements == less downforce, less drag, and cleaner air flow behind them.

Most teams use the extra elements for flow control towards the back.

Do they? Have you seen their CFD models and wind tunnel results? How do you know that's what they're using them for?

Notably, where most teams use multiple elements is in fact right in front of the front wheels. The reason for that is simple – they can extract maximum downforce from air hitting the front wing there that is going to go straight into the front wheel, so they can't control how it flows back down the car anyway. Lots of elements on other areas of the wing is relatively rare.

Yes, they create turbulent ariflow and more drag, but also better airflow control and redirection.

No, it allows the air to stay attached to a steeper AoA front wing.

It is always a compromise. Hence why I said "efficient downforce creation" in the case of the mclaren situation, which most certainly has a better L/D.

Actually, it almost certainly has worse L/D than the other wings – but also has less turbulent flow coming off the back of it.

I say almost, because I haven't seen their CFD or wind tunnel results either, so I can't know for sure. But, the basic aero theory is that McLaren's wing will produce less downforce, and a cleaner airflow to the back.

[turbof1]

Except that we well know that multi element front wings are for quite the reverse of this purpose

More elements == more downforce, more drag, and more turbulent air flow behind them
Fewer elements == less downforce, less drag, and cleaner air flow behind them.

Most teams use the extra elements for flow control towards the back.

Do they? Have you seen their CFD models and wind tunnel results? How do you know that's what they're using them for?

Notably, where most teams use multiple elements is in fact right in front of the front wheels. The reason for that is simple – they can extract maximum downforce from air hitting the front wing there that is going to go straight into the front wheel, so they can't control how it flows back down the car anyway. Lots of elements on other areas of the wing is relatively rare.

Yes, they create turbulent ariflow and more drag, but also better airflow control and redirection.

No, it allows the air to stay attached to a steeper AoA front wing.

It is always a compromise. Hence why I said "efficient downforce creation" in the case of the mclaren situation, which most certainly has a better L/D.

Actually, it almost certainly has worse L/D than the other wings – but also has less turbulent flow coming off the back of it.

I say almost, because I haven't seen their CFD or wind tunnel results either, so I can't know for sure. But, the basic aero theory is that McLaren's wing will produce less downforce, and a cleaner airflow to the back.

These aren't your ordinary multiple element wings; alot of the "elements" are only just that at the endplates and not at the wing tips (slots in wing at the endplate). That and of course the smaller winglets, cascades who are obviously there to redirect airflow around the tyres. What most likely is going on is that they use the fw area in front of the tyres to create the most downforce because the air is uncontrolable when it comes near the tyre. All of the rest of the FW has vortex creators all over it.

I think you are making too much a comparison to the pre-2009 fw's.

Imo, its useless to talk in terms of cfd, simply none of us have representative cfd images. Else this discussion wouldn't be here in the first place. It is still called an opinion .

[Pup]

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.

You're assuming that at some point, the engineers took a look at how much rear downforce they had and decided they're good. I doubt that ever happens.

[Pup]

More elements == more downforce, more drag, and more turbulent air flow behind them
Fewer elements == less downforce, less drag, and cleaner air flow behind them.

Usually. But as discussed below, a single element doesn't necessarily produce less down force - it could just be better designed and not need to be split into multiple elements.

The other factor is how the various vortexes from the wing bits interact among one another. Like two planes flying wing to wing, it's possible that some of the vortexes cancel one another out, eliminating the drag penalty.

[turbof1]

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.

You're assuming that at some point, the engineers took a look at how much rear downforce they had and decided they're good. I doubt that ever happens.

Not exactly. It was just a possible explanation for why it didn't came it mind last year. Nowhere did I said how the engineer work. If they were happy with how the wing performed and if they believed developing other parts of the car could bring more performance, then they simply putted their resources into that.

[wesley123]

Do they? Have you seen their CFD models and wind tunnel results? How do you know that's what they're using them for?

On the other hand, do you know what they are used for?

Notably, where most teams use multiple elements is in fact right in front of the front wheels. The reason for that is simple – they can extract maximum downforce from air hitting the front wing there that is going to go straight into the front wheel,

No, they use multiple elements there to inject air to the underside of the wing. This is done to prevent stall from that wing section, the outer section is a very sensitive part of the wing due to the Front wheel it's influence there.

So with that, stall is prevented in that area, this gives less peak downfore (more elements =/= more downforce) but more consistent downforce as there is more consistent flow on the underside and the area is less effected by the front wheel.

so they can't control how it flows back down the car anyway.

They can, that the flow doesnt stall in that area has a huge effect on how it is sent around the tire. Also teams have modified their wheel hubs so they blow clean air out of the wheel, which has a benificial effect on the front wing itself, as well as a positive effect on the air downstream.

For example Williams uses this solution, they have a whole duct in that area as well as a 'blown axle'.

Yes, they create turbulent ariflow and more drag, but also better airflow control and redirection.

No, it allows the air to stay attached to a steeper AoA front wing.

Both are right. Yes a multiple plane wing has more drag than an single plane wing with the same AoA, but it is also less sensitive, which is mainly a goal in this outer section. Also because it doesnt stall the airflow can be controlled better.

It is always a compromise. Hence why I said "efficient downforce creation" in the case of the mclaren situation, which most certainly has a better L/D.

Actually, it almost certainly has worse L/D than the other wings – but also has less turbulent flow coming off the back of it.

What makes you think that? so you are actually saying it has less turbulence from the wing(which would rougly translate to less drag) but it's larger planes would generate more df compared to the other wings. So that would translate to a higher L/D. Too bad that L/D isn't everything though.

I say almost, because I haven't seen their CFD or wind tunnel results either, so I can't know for sure. But, the basic aero theory is that McLaren's wing will produce less downforce, and a cleaner airflow to the back.

I am sure it would produce more downforce. Why?

In my previous post I showed how other Front wings evolved, but McLarens didnt. I picked 2010/2013 for every team I had shown.

But to get back to 2010, they had DDD back then, F-Ducts, and also the EBD. Cars then had more rear downforce than they have now. This had to be balanced out by the fornt df. So then they had more rear df, and also needed more front df. So back then Front Wings were much more about downforce production, because they needed to make more front df. With the cuts in rear df(ban of DDD etc.) the front df has to follow too. So with that, Front Wings are much 'easier' parts, they dont need to generate lots of df any more and became more of an device to send better airflow to the back than to generate lots of df in it's own right.

So in that aspect, every front wing changed in 2013, except for McLarens, which is still pretty similar to 2010, the year that Front wings were still about generating lots of df, so therefore I'd say the McLaren front wing has more df than others, but on the other hand also has less effect on airflow itself and how it sends it rearwards.

So compared to 2010 there is a huge change in front wing philosophy, and everyone apart from McLaren changed it.

[beelsebob]

Notably, where most teams use multiple elements is in fact right in front of the front wheels. The reason for that is simple – they can extract maximum downforce from air hitting the front wing there that is going to go straight into the front wheel,

No, they use multiple elements there to inject air to the underside of the wing. This is done to prevent stall from that wing section, the outer section is a very sensitive part of the wing due to the Front wheel it's influence there.

So with that, stall is prevented in that area, this gives less peak downfore (more elements =/= more downforce) but more consistent downforce as there is more consistent flow on the underside and the area is less effected by the front wheel.

No, more elements absolutely does mean more downforce in this instance. In theory a high AoA single element would produce more, in practice, it doesn't, because it stalls. The multiple elements allow for a higher AoA wing, and hence more downforce production because of the lack of separation. This is done in particular in front of the front wheel, because 1) it's more prone to separation, as you point out, and 2) because the air coming off the back of the front wing is going to get abused by the front wheel anyway, so they don't care that it's been worked hard, and is now horribly turbulent.

so they can't control how it flows back down the car anyway.

They can, that the flow doesnt stall in that area has a huge effect on how it is sent around the tire. Also teams have modified their wheel hubs so they blow clean air out of the wheel, which has a benificial effect on the front wing itself, as well as a positive effect on the air downstream.

For example Williams uses this solution, they have a whole duct in that area as well as a 'blown axle'.

Yes, this does not mean that they can neatly determine "air flowing off this flick up on the front wing, here, will flow to this point along the side pods, and round to this point at the rear wing. It means that they know that the front wheel generates a lot of turbulence, and that they do their best to correct that turbulence. Correcting turbulence as best you can is not the same as nice, predictable airflow.

It is always a compromise. Hence why I said "efficient downforce creation" in the case of the mclaren situation, which most certainly has a better L/D.

Actually, it almost certainly has worse L/D than the other wings – but also has less turbulent flow coming off the back of it.

What makes you think that? so you are actually saying it has less turbulence from the wing(which would rougly translate to less drag) but it's larger planes would generate more df compared to the other wings. So that would translate to a higher L/D. Too bad that L/D isn't everything though.

No, it's larger planes would not generate more df compared to a multi element wing, because those large elements can not be set at as high an AoA, because they would stall. The result is that while it produces less turbulence, and less drag, it also produces less downforce.

I say almost, because I haven't seen their CFD or wind tunnel results either, so I can't know for sure. But, the basic aero theory is that McLaren's wing will produce less downforce, and a cleaner airflow to the back.

I am sure it would produce more downforce. Why?

In my previous post I showed how other Front wings evolved, but McLarens didnt. I picked 2010/2013 for every team I had shown.

But to get back to 2010, they had DDD back then, F-Ducts, and also the EBD. Cars then had more rear downforce than they have now. This had to be balanced out by the fornt df. So then they had more rear df, and also needed more front df. So back then Front Wings were much more about downforce production, because they needed to make more front df. With the cuts in rear df(ban of DDD etc.) the front df has to follow too. So with that, Front Wings are much 'easier' parts, they dont need to generate lots of df any more and became more of an device to send better airflow to the back than to generate lots of df in it's own right.

Your argument can be applied in reverse too. McLaren in the past had a low downforce front wing that produced excellent airflow to the rear of the car, in the mean time, they chose to use the low nose, and the snow plough to produce their front downforce. McLaren have chosen to keep their (relatively) low downforce design front wing, but ditched the snowplough and low nose to 1) balance the car out, and 2) provide more airflow to the rear of the car.

[wesley123]

So with that, stall is prevented in that area, this gives less peak downfore (more elements =/= more downforce) but more consistent downforce as there is more consistent flow on the underside and the area is less effected by the front wheel.

No, more elements absolutely does mean more downforce in this instance. In theory a high AoA single element would produce more, in practice, it doesn't, because it stalls.

No it doesnt mean more downforce, it means less sensitive downforce, the downforce is more consistent, albeit a bit less compared to a 3 plane wing or even a 2 plane wing. So while there is less peak downforce, the downforce is pretty much always there which causes for a less sensitvie wing, which is the point of the slots.

The multiple elements allow for a higher AoA wing,

They indeed do, but is that really done with the current wings? If I take a look at the wings I dont really see a much higher AoA, all I see is a split up wing. Also for example Red Bull's recent front wing update adds a slot 20mm max. from the Trailing edge. a slot in that area only splits up a small wing area in an even smaller area. The 20mm max. element would also be too small to push the AoA and is more used to inject more airflow to the underside to guide air around the wing.

and hence more downforce production because of the lack of separation.

Indeed, but there is less peak downforce. Overall the downforce that you are having is always there with more slots.

This is done in particular in front of the front wheel, because 1) it's more prone to separation, as you point out, and 2) because the air coming off the back of the front wing is going to get abused by the front wheel anyway, so they don't care that it's been worked hard, and is now horribly turbulent.

Overall it is less turbulent and the injected flow will keep the flow attached, and thus follows the shape of the wing/endplate, which gives better flow around the end plate.

They can, that the flow doesnt stall in that area has a huge effect on how it is sent around the tire. Also teams have modified their wheel hubs so they blow clean air out of the wheel, which has a benificial effect on the front wing itself, as well as a positive effect on the air downstream.

For example Williams uses this solution, they have a whole duct in that area as well as a 'blown axle'.

Yes, this does not mean that they can neatly determine "air flowing off this flick up on the front wing, here, will flow to this point along the side pods, and round to this point at the rear wing. It means that they know that the front wheel generates a lot of turbulence, and that they do their best to correct that turbulence. Correcting turbulence as best you can is not the same as nice, predictable airflow.

True, flwo in this area generally isnt that great, but improvements to the wheelhub and slots can manage airflow around the wheel better and also manage the dirty air from the wheel better, making it a bit less dirty.

What makes you think that? so you are actually saying it has less turbulence from the wing(which would rougly translate to less drag) but it's larger planes would generate more df compared to the other wings. So that would translate to a higher L/D. Too bad that L/D isn't everything though.

No, it's larger planes would not generate more df compared to a multi element wing, because those large elements can not be set at as high an AoA, because they would stall. The result is that while it produces less turbulence, and less drag, it also produces less downforce.

They actually do. A 3 plane wing like the McLAren generates more df. It has more area to work on, compared to the smaller wing planes on other wings. Yes it cannot be pushed to higher AoA's compared to higher elements, however, are these multiple elements actually pushed to higher AoA? The way I see them they dont, actually they are pretty far off if you ask me. For example the adjustable flap are in wuite often cases not even at maximum length, and are actually shorter than allowed to be, also if you look to the end plate height, you'll notice the flap's trailing edge is below that. So while a 4 plane wing can be pushed to higher AoA, it isnt really done on current front wings. A 3 plane wing itself would be sufficient enough as it isnt pushed to aero critical levels in current application, it is only done to create a less aero sensitive wing.

I am sure it would produce more downforce. Why?

In my previous post I showed how other Front wings evolved, but McLarens didnt. I picked 2010/2013 for every team I had shown.

But to get back to 2010, they had DDD back then, F-Ducts, and also the EBD. Cars then had more rear downforce than they have now. This had to be balanced out by the fornt df. So then they had more rear df, and also needed more front df. So back then Front Wings were much more about downforce production, because they needed to make more front df. With the cuts in rear df(ban of DDD etc.) the front df has to follow too. So with that, Front Wings are much 'easier' parts, they dont need to generate lots of df any more and became more of an device to send better airflow to the back than to generate lots of df in it's own right.

Your argument can be applied in reverse too. McLaren in the past had a low downforce front wing that produced excellent airflow to the rear of the car, in the mean time, they chose to use the low nose, and the snow plough to produce their front downforce. McLaren have chosen to keep their (relatively) low downforce design front wing, but ditched the snowplough and low nose to 1) balance the car out, and 2) provide more airflow to the rear of the car.

True, I cant add anything to that.

[turbof1]

No, more elements absolutely does mean more downforce in this instance. In theory a high AoA single element would produce more, in practice, it doesn't, because it stalls. The multiple elements allow for a higher AoA wing, and hence more downforce production because of the lack of separation. This is done in particular in front of the front wheel, because 1) it's more prone to separation, as you point out, and 2) because the air coming off the back of the front wing is going to get abused by the front wheel anyway, so they don't care that it's been worked hard, and is now horribly turbulent.

They have to run more AoA in the first place to get the extra downforce. If they use multiple elements but keep the same overal AoA as the single element wing, you are actually loosing peak downforce (given the AoA of the single element wing is beneath the point of stalling). The point is consistent downforce.
Basicilly on this we are all giving the exact same explanation, but you are thinking it is for more downforce, whereas me and wesley think it mainly for preventing stalling the wing by wheel turbulence. Again, you are referring to pre-2009 FWs, which had increasingly more elements to get front DF levels higher. The main use now is keep the wing from stalling.

Yes, this does not mean that they can neatly determine "air flowing off this flick up on the front wing, here, will flow to this point along the side pods, and round to this point at the rear wing. It means that they know that the front wheel generates a lot of turbulence, and that they do their best to correct that turbulence. Correcting turbulence as best you can is not the same as nice, predictable airflow.

I think basicilly that has become the complete point of F1 these days! Teams spend HUGE amount of resources optimising every bit of airflow and manipulating it, and they spend that same again on getting better cfd and a better windtunnel to get closer to the reality. Do we know if they can neatly determine it? Only the teams know how big the correlation between the simulation equipment and on track data is. Do we know that they do everything in their power to neatly determine it? Yes we infact do.

No, it's larger planes would not generate more df compared to a multi element wing, because those large elements can not be set at as high an AoA, because they would stall. The result is that while it produces less turbulence, and less drag, it also produces less downforce.

If the AoA is beneath the single element's stalling point, the multi element wing gives less DF, simply due less surface generating DF.
It becomes much more complicated when we take into account that stalling is not even accros the complete wing. It is more prone to stalling close to the wheels. Teams nowadays speak in terms of "...% of the wing stalls".

Your argument can be applied in reverse too. McLaren in the past had a low downforce front wing that produced excellent airflow to the rear of the car, in the mean time, they chose to use the low nose, and the snow plough to produce their front downforce. McLaren have chosen to keep their (relatively) low downforce design front wing, but ditched the snowplough and low nose to 1) balance the car out, and 2) provide more airflow to the rear of the car.

You are getting some things mixed up I believe. With removing the slow plow and rising the nose they increase air volume. You can only get with that so far. Most teams now use the FW to create vortices all over the place to redirect airflow. They want to keep airflow from spilling out of its desired path. That out of the way, I agree with that piece.

[beelsebob]

So with that, stall is prevented in that area, this gives less peak downfore (more elements =/= more downforce) but more consistent downforce as there is more consistent flow on the underside and the area is less effected by the front wheel.

No, more elements absolutely does mean more downforce in this instance. In theory a high AoA single element would produce more, in practice, it doesn't, because it stalls.

No it doesnt mean more downforce, it means less sensitive downforce, the downforce is more consistent, albeit a bit less compared to a 3 plane wing or even a 2 plane wing. So while there is less peak downforce, the downforce is pretty much always there which causes for a less sensitvie wing, which is the point of the slots.

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.

[turbof1]

We both acknowledge that. Again same explanation (now in math). But you are assuming that the AoA changes. If AoA stays the same (and beneath the stalling point) then less elements produce more DF.

Back in the day when it was allowed teams indeed ran higher AoA and just increased the elements, both for rear wing (until the elements got limited to 2) and the front wing (more towards 2006 they began to increase). With the introduction of the 2009 rules, the FW grew substantial. Having now more surface to create downforce, they didn't need multi elements anymore. What was the point anyway; with rear downforce being hugely limited, even with DDD's, front downforce also had to be diminished to keep the aero balance. AoA get diminished beneath the stalling point. less elements meant less drag and better L/D.

Now, we see reintroduction to more elements, but only in front of the wheels. Teams nowadays use the airflow that doesn't get to the wheels for feeding the rear of the car, and make the surface of the FW in front of the wheels work much harder to create the majority of the front DF. Because it has to work harder, it is more prone to stalling in that area, hence the multiple elements there.

[beelsebob]

We both acknowledge that. Again same explanation (now in math). But you are assuming that the AoA changes. If AoA stays the same (and beneath the stalling point) then less elements produce more DF.

Sure – the point is that the other teams can run (and in fact need to run) higher AoA front wings. And in doing so, they produce a more turbulent flow to the rear of the car. They get more downforce in doing so, more drag, and more turbulence.

[turbof1]

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.