Ferrari SF-26

[bananapeel23]

Rumors are that the flipping rear wing would be worth 4-5 kW on the straights:
https://www.formulapassion.it/f1/f1-new ... ro-il-7-gp

Any idea of what this would mean in terms of Cd reduction?

The link goes to another link, which is "members only", so haven't seen how they derived the 4-5KW number. But for a moment we can assume they are correct, and back-calculate in a back-of-the-envelope crude way :

Lets say we are talking of speeds less than 340kph (which is when the tapering of MGU-K deployment is forced) and hence the full 750KW is available to deploy. Cd1 is the SLM drag with typical wing and Cd2 is the SLM drag with the macarena wing. Let's also make the blunt assumption that all the 750KW is consumed by aero-drag, with very little mechanical friction or rolling resistance losses :

we have 750KW = const x Cd1 x (V1)^3 = const x Cd2 x (V2)^3
The claim is that if it were Cd2 in place of Cd1, the car would need only 745KW.
we have 745KW = const x Cd2 x (V1)^3 , which in turn would mean Cd2 = 0.9933 x Cd1 , a.k.a reduction of Cd by 0.67%
With the full 750KW, the equation now becomes : (V1)^3 = 0.9933 x (V2)^3 , which in turn would mean V2 = 1.002243 x V1 , a.k.a increase in top speed by 0.22% , with the extra 5 KW. If we are talking of V1=330kph, we would get V2=330.74kph. Not much top speed benefit, really.

So I doubt whether the 5KW is a correct estimate, because Ferrari spent quite a few millions developing the macarena wing.

Could it be that it is worth as much time over a lap as 5kw of engine power would be? It’s a very unintuitive way of putting it and doesn’t quite make sense as a point of comparison, but it’s the only way I could interpret it after seeing the math. This interpretation also tracks more with the top speed advantage it seems to provide, which was in the ballpark of 5-8 kph unless I’m misremembering.

I guess it could also make sense for a comparison if your goal is to put the value of the macarena wing in proportion to the value of the CR trick.

[venkyhere]

Rumors are that the flipping rear wing would be worth 4-5 kW on the straights:
https://www.formulapassion.it/f1/f1-new ... ro-il-7-gp

Any idea of what this would mean in terms of Cd reduction?

The link goes to another link, which is "members only", so haven't seen how they derived the 4-5KW number. But for a moment we can assume they are correct, and back-calculate in a back-of-the-envelope crude way :

Lets say we are talking of speeds less than 340kph (which is when the tapering of MGU-K deployment is forced) and hence the full 750KW is available to deploy. Cd1 is the SLM drag with typical wing and Cd2 is the SLM drag with the macarena wing. Let's also make the blunt assumption that all the 750KW is consumed by aero-drag, with very little mechanical friction or rolling resistance losses :

we have 750KW = const x Cd1 x (V1)^3 = const x Cd2 x (V2)^3
The claim is that if it were Cd2 in place of Cd1, the car would need only 745KW.
we have 745KW = const x Cd2 x (V1)^3 , which in turn would mean Cd2 = 0.9933 x Cd1 , a.k.a reduction of Cd by 0.67%
With the full 750KW, the equation now becomes : (V1)^3 = 0.9933 x (V2)^3 , which in turn would mean V2 = 1.002243 x V1 , a.k.a increase in top speed by 0.22% , with the extra 5 KW. If we are talking of V1=330kph, we would get V2=330.74kph. Not much top speed benefit, really.

So I doubt whether the 5KW is a correct estimate, because Ferrari spent quite a few millions developing the macarena wing.

Are you sure of your calculations? 5kW=6.5CV is in the ballpark of rumored benefit of CR trick.,

When 5KW is 0.67% of the peak power = 750KW (and peak power is used when car is running in the straights @ ~Vmax) , I don't know what 'considerable' difference it can make. The calculations are very basic, without considering 2nd order effects etc. the aim is to provide 'ballpark' understanding.

[wuzak]

The link goes to another link, which is "members only", so haven't seen how they derived the 4-5KW number. But for a moment we can assume they are correct, and back-calculate in a back-of-the-envelope crude way :

Lets say we are talking of speeds less than 340kph (which is when the tapering of MGU-K deployment is forced) and hence the full 750KW is available to deploy. Cd1 is the SLM drag with typical wing and Cd2 is the SLM drag with the macarena wing. Let's also make the blunt assumption that all the 750KW is consumed by aero-drag, with very little mechanical friction or rolling resistance losses :

we have 750KW = const x Cd1 x (V1)^3 = const x Cd2 x (V2)^3
The claim is that if it were Cd2 in place of Cd1, the car would need only 745KW.
we have 745KW = const x Cd2 x (V1)^3 , which in turn would mean Cd2 = 0.9933 x Cd1 , a.k.a reduction of Cd by 0.67%
With the full 750KW, the equation now becomes : (V1)^3 = 0.9933 x (V2)^3 , which in turn would mean V2 = 1.002243 x V1 , a.k.a increase in top speed by 0.22% , with the extra 5 KW. If we are talking of V1=330kph, we would get V2=330.74kph. Not much top speed benefit, really.

So I doubt whether the 5KW is a correct estimate, because Ferrari spent quite a few millions developing the macarena wing.

Are you sure of your calculations? 5kW=6.5CV is in the ballpark of rumored benefit of CR trick.,

When 5KW is 0.67% of the peak power = 750KW (and peak power is used when car is running in the straights @ ~Vmax) , I don't know what 'considerable' difference it can make. The calculations are very basic, without considering 2nd order effects etc. the aim is to provide 'ballpark' understanding.

Unless you are talking overtake mode, the maximum power of the MGUK is 150kW, therefore, the total power is 550kW.

Still, the increase would only be about 1km/h.

But at 331km/h you've lost another 5kW of deployment from the MGUK.

[matteosc]

Rumors are that the flipping rear wing would be worth 4-5 kW on the straights:
https://www.formulapassion.it/f1/f1-new ... ro-il-7-gp

Any idea of what this would mean in terms of Cd reduction?

The link goes to another link, which is "members only", so haven't seen how they derived the 4-5KW number. But for a moment we can assume they are correct, and back-calculate in a back-of-the-envelope crude way :

Lets say we are talking of speeds less than 340kph (which is when the tapering of MGU-K deployment is forced) and hence the full 750KW is available to deploy. Cd1 is the SLM drag with typical wing and Cd2 is the SLM drag with the macarena wing. Let's also make the blunt assumption that all the 750KW is consumed by aero-drag, with very little mechanical friction or rolling resistance losses :

we have 750KW = const x Cd1 x (V1)^3 = const x Cd2 x (V2)^3
The claim is that if it were Cd2 in place of Cd1, the car would need only 745KW.
we have 745KW = const x Cd2 x (V1)^3 , which in turn would mean Cd2 = 0.9933 x Cd1 , a.k.a reduction of Cd by 0.67%
With the full 750KW, the equation now becomes : (V1)^3 = 0.9933 x (V2)^3 , which in turn would mean V2 = 1.002243 x V1 , a.k.a increase in top speed by 0.22% , with the extra 5 KW. If we are talking of V1=330kph, we would get V2=330.74kph. Not much top speed benefit, really.

So I doubt whether the 5KW is a correct estimate, because Ferrari spent quite a few millions developing the macarena wing.

I would be surprise if a Ferrari rumor would downplay the gain of a solution that they found, but if it is only 4-5 kW this looks like a minor advantage.
It could be that that number is defined as average over the whole straight (much lower speed) or something like that. Looking forward to see it on the track one day.

[AR3-GP]

Wasn't the number 4-5km/h, not 4-5 kW. That's a big difference.

[Seanspeed]

Wasn't the number 4-5km/h, not 4-5 kW. That's a big difference.

The reporting is saying kw. Weird way to quantify this, really.

[venkyhere]

Wasn't the number 4-5km/h, not 4-5 kW. That's a big difference.

Ah.
That makes more sense.
Assuming a baseline top speed of 330 kph with normal wing, that would mean
Cd (macarena) = 0.9559 x Cd (normal), a drag reduction of 4.4% for the extra 5kph, which sounds realistic.
(higher baseline top speed would mean smaller reduction)

[AR3-GP]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

[sucof]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

Hm interesting point. It could make the wing more flexible, while driving. Outside it could me measured flexing less.
Though I wonder if flexi wings matter much in this new active aero era...?

[SiLo]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

Dreamland for the rear wing really, it's in a constant flow of air and unlikely to receive any benefit from any kind of heating.

[AR3-GP]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

Hm interesting point. It could make the wing more flexible, while driving. Outside it could me measured flexing less.
Though I wonder if flexi wings matter much in this new active aero era...?

It will matter. There are circuits with both low and high speed corners. The corner mode will be active in both types of corners. You want high angle of attack in the slow corners, but you won't need so much downforce for the higher speed corners (think like blanchimont, 130R). So there are still some incremental gains to be had with wing flexing.

[AR3-GP]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

Dreamland for the rear wing really, it's in a constant flow of air and unlikely to receive any benefit from any kind of heating.

There was that one year that Renault ran heat shielding on their rear wing because they were using exhaust blowing. Ferrari doesn't have any heat shielding so it probably doesn't get very hot. Maybe that's a clue that there's not that much mass flow from these lower power combustion engines.

[matteosc]

Wasn't the number 4-5km/h, not 4-5 kW. That's a big difference.

Ah.
That makes more sense.
Assuming a baseline top speed of 330 kph with normal wing, that would mean
Cd (macarena) = 0.9559 x Cd (normal), a drag reduction of 4.4% for the extra 5kph, which sounds realistic.
(higher baseline top speed would mean smaller reduction)

The number reported was kW, not km/h. 4-5 km/h would be huge, but it is not what is rumored to be.

[venkyhere]

Wasn't the number 4-5km/h, not 4-5 kW. That's a big difference.

Ah.
That makes more sense.
Assuming a baseline top speed of 330 kph with normal wing, that would mean
Cd (macarena) = 0.9559 x Cd (normal), a drag reduction of 4.4% for the extra 5kph, which sounds realistic.
(higher baseline top speed would mean smaller reduction)

The number reported was kW, not km/h. 4-5 km/h would be huge, but it is not what is rumored to be.

As the crude calculation showed, 4-5 KW is too little gain for inventing a whole new rear wing system. Which could mean, that the aim of the macarena wing is not really drag reduction, but something else like play-room for lower static rear ride height

[Nickel]

One of the side effects of this invention is heating the rear wing. Could they take advantage of that, somehow? thermal expansion and what not?

Hm interesting point. It could make the wing more flexible, while driving. Outside it could me measured flexing less.
Though I wonder if flexi wings matter much in this new active aero era...?

It will matter. There are circuits with both low and high speed corners. The corner mode will be active in both types of corners. You want high angle of attack in the slow corners, but you won't need so much downforce for the higher speed corners (think like blanchimont, 130R). So there are still some incremental gains to be had with wing flexing.

Shifting the aero balance forward in high speed corners and rearward in low speed corners seems like the opposite of what you'd want. I'd view this as unlikely but I'm an idiot.