2017-2020 Aerodynamic Regulations Thread

[FPV GTHO]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

[Pierce89]

Sails do help to stabilize flow.

But they dont push tire turbulence away from the rear wing. They prevent spanwise flow migration in turns. Which is "stabilizing" the flow. I have a beef with the tire turbulence bs.

[Pierce89]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

That lower rear wing also has a MUCH better aspect ratio. The front wing will also have a better aspect ratio.

[zztopless]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

My understanding that that any potential issues with turbulent air from the bodywork, potentially causing problems for the lower rear wings, should be more than off-set by the increased width (it is my understanding that a wider wing that needs less angle of attack to achieve a given level of downforce produces less drag, relative to a narrower wing that needs to run a higher AOA to get the same DF levels), as well as better interaction with the diffuser.

Also, when you think about how good the teams have gotten at controlling the airflow with the intricate front wings and add in the much larger barge boards, it makes me winder if turbulent air form the bodywork will even be an issue (especially for the top teams)...

[basti313]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

My understanding that that any potential issues with turbulent air from the bodywork, potentially causing problems for the lower rear wings, should be more than off-set by the increased width (it is my understanding that a wider wing that needs less angle of attack to achieve a given level of downforce produces less drag, relative to a narrower wing that needs to run a higher AOA to get the same DF levels), as well as better interaction with the diffuser.

Yes, I think there is no question, that we will see higher DF levels.
But the turning point will still be how much air they get to the wing. This is why I do not totally buy the "longer wheelbase for bardgeboards" rumors. To me it looks much more beneficial to make the engine area longer. This will give much room to make it more flat to get the rear wing working better and will give more space for the coke bottle to get the diffusor working better.

Looking at the posted pics from AMuS:

To me it looks much too bulky between "Castrol" and "Michael Kors" badges. My bet is that they will reduce the width of the area between intake and shoulder area to the minimum, e.g. to the width they need for the intake.

Maybe this will be the comeback of the McLaren with the small turbo offering more possibilities to shrink that area. Also the Merc with the split turbo should be good on a "long and low" setup.

[PhillipM]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

That lower rear wing also has a MUCH better aspect ratio. The front wing will also have a better aspect ratio.

And outside of isolation you also have much more area which can be dedicated entirely to working aero compared to that which you need simply for packaging the driver, engine, radiators, thermal management, etc.

[FPV GTHO]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

My understanding that that any potential issues with turbulent air from the bodywork, potentially causing problems for the lower rear wings, should be more than off-set by the increased width (it is my understanding that a wider wing that needs less angle of attack to achieve a given level of downforce produces less drag, relative to a narrower wing that needs to run a higher AOA to get the same DF levels), as well as better interaction with the diffuser.

Also, when you think about how good the teams have gotten at controlling the airflow with the intricate front wings and add in the much larger barge boards, it makes me winder if turbulent air form the bodywork will even be an issue (especially for the top teams)...

In isolation, sure, one point of downforce will be more efficient on a wider wing than a narrow wing. But if you put the same load on a low wing as a high wing, the high wing is in cleaner air and also applies more load through the chassis through a larger leverage action. There's also the consideration that chasing downforce gains through the wings is less efficient than gains through the floor.

[Pierce89]

I don't think the aero is more efficient. The floor changes will be, but the lower rear wing won't be.

My understanding that that any potential issues with turbulent air from the bodywork, potentially causing problems for the lower rear wings, should be more than off-set by the increased width (it is my understanding that a wider wing that needs less angle of attack to achieve a given level of downforce produces less drag, relative to a narrower wing that needs to run a higher AOA to get the same DF levels), as well as better interaction with the diffuser.

Also, when you think about how good the teams have gotten at controlling the airflow with the intricate front wings and add in the much larger barge boards, it makes me winder if turbulent air form the bodywork will even be an issue (especially for the top teams)...

In isolation, sure, one point of downforce will be more efficient on a wider wing than a narrow wing. But if you put the same load on a low wing as a high wing, the high wing is in cleaner air and also applies more load through the chassis through a larger leverage action. There's also the consideration that chasing downforce gains through the wings is less efficient than gains through the floor.

The only force higher wing could increase through leverage is drag if you look at the mounting and how the forces are going through the wing to the chassis. In reality, the whole leverage thing doesn't matter anyways because leverage can't be used to obtain higher overall downforce. All it can do is change the balance authority between the front and rear.

[FPV GTHO]

If it wasn't giving more downforce, it wouldn't be changing the balance.

[PhillipM]

I think you may want to rethink that one. Leverage=! downforce.

A more rearward wing changes balance by shifting load off the front wheels onto the rear.

[Just_a_fan]

It's possible for a more effective rear wing to improve front end downforce too. By aiding flow under the car, the flow behind the front wing can be improved which can make it more effective too. We must never forget that these cars are whole devices, not just a collection of parts.

[Pierce89]

If it wasn't giving more downforce, it wouldn't be changing the balance.

DUDE, I said you can't increase over all DF or efficiency through leverage, as the leverage from the other wing will always cancel it out if you try to do it on both ends. Also.any "leverage induced" df you get on one end take df off the other end.

[SR71]

I think the slotted floors (in front of the rear wheel) are a small but underrated 2016 development feature.

Anyone know if the impact of the wider floor + unchanged side pod width will increase the efficacy of slotted/serrated floors?

[roon]

In isolation, sure, one point of downforce will be more efficient on a wider wing than a narrow wing. But if you put the same load on a low wing as a high wing, the high wing is in cleaner air and also applies more load through the chassis through a larger leverage action. There's also the consideration that chasing downforce gains through the wings is less efficient than gains through the floor.

The only force higher wing could increase through leverage is drag if you look at the mounting and how the forces are going through the wing to the chassis. In reality, the whole leverage thing doesn't matter anyways because leverage can't be used to obtain higher overall downforce. All it can do is change the balance authority between the front and rear.

I think you're both talking about the same thing. Correct me if I'm wrong. FPV, you're saying that the higher mounted rear wing imparts a greater total force per a given downforce 'point' due to a greater lever arm action upon the rear axle. Pierce89, you're saying the only extra force to be found on a high-mount rear wing will be from drag (operating longitudinaly i.e. a backward force as opposed to the vertical, downforce).

Since both a backward and a downward force will still be acting upon the same fulcrum (rear axle), there will be an increase in the twisting moment operating on said pivot. So you're both describing the same phenomenon, although I think FPV said it more cryptically. I couldn't understand what you were getting at, FPV, til I read Pierce's post.

My own summation: The rear wings in 2017 will be approximately in the same position longitudinally (front-to-back) as they are per 2009-2016 rules. RW downforce will thus be acting upon the fulcrum of the rear axle with the same lever arm. Off the top of my head, that is ~300mm (half a tire diameter plus some?) The drag force lever arm, however, will decrease with the lower rear wing and its shorter endplates.

[godlameroso]

I still think that the new rear wing has much more potential to create downforce, given it's placement and geometry of the diffuser, and the wider floor.

I think the slotted floors (in front of the rear wheel) are a small but underrated 2016 development feature.

Anyone know if the impact of the wider floor + unchanged side pod width will increase the efficacy of slotted/serrated floors?

There is definitely the possibility to exploit this area, especially given the wider floor and higher possibility for undercut or using ducts that pass through the side pod to enhance the potential of this area.

The challenge would be stabilizing the flow structures in that area, because it could cause chassis problem if they're sensitive to pitch for instance.

Truth be told there's so much that can be developed that the teams are scrambling for time, even those that got a head start.

Even now that teams are in the process of passing the crash tests, and have their chassis signed off for manufacturing, they're kicking themselves because there's not enough time to implement neat new things they've learned.