McLaren MCL35M

[pazazamadaz]

And with the posting of the obligatory FW picks the F1 weekend has officially started!

[mclaren111]

Hooray Hooray

[_cerber1]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

[MrGapes]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

https://pbs.twimg.com/media/E4FhW5FXEAA ... =4096x4096

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

[mclaren111]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

https://pbs.twimg.com/media/E4FhW5FXEAA ... =4096x4096

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

Bigger update than I expected...

Let's hope it works like bomb...

[_cerber1]

I predict -0.5 in corners and -0.9 on straights.

[aerofoilf1]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

https://pbs.twimg.com/media/E4FhW5FXEAA ... =4096x4096

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

The diffuser expansion creates upwash/outwash and this new endplate design aims to make the most of this by introducing multiple elements that will produce some local load.

[Herr_Koos]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

https://pbs.twimg.com/media/E4FhW5FXEAA ... =4096x4096

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

The diffuser expansion creates upwash/outwash and this new endplate design aims to make the most of this by introducing multiple elements that will produce some local load.

That sounds very clever but I didn't understand any of it.

[godlameroso]

From @racingtech5

McLaren MCL35M Rear Wing Endplate

Revised lower part of endplate with upwashing elements. New concept that no other team has used before - over many years, the trend has been to have outwashing elements like McLaren had with its old design.

https://pbs.twimg.com/media/E4FhW5FXEAA ... =4096x4096

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

The diffuser expansion creates upwash/outwash and this new endplate design aims to make the most of this by introducing multiple elements that will produce some local load.

Divergent flow. The flaps restrict the high pressure flow from merging with the low pressure upwash of the diffuser. Remember the rotation of the vortices under the floor. The direction of the air flow and rotation in that region is TOWARDS the center of the car, not away. The diffuser flow is from the center and diverges outward in two spirals. It is moving up and out from the center, and down and in from the periphery. Imagine flexing like Hulk Hogan(by flexing like Hulk Hogan) and you'll get a feel for how the air moves out of the diffuser when looking at the rear of the car.

Learn more here.




Here we see exactly the same rotation of the diffuser airflow on the right side of the car when seen from the rear, but explained in a macro model.

[PhillipM]

It's not really for local load, the split/canted endplates since the changes a few years ago makes those vertical vanes less effective at expansion because air draws in through the gap anyway, this change is more to use the up and outwash from the diffuser to keep airflow attached at the endplates of the rear wing.
Basically the same thing the upper ones are already doing.
It lets you run the rear wing closer to stall without risking detachment/unsteady aero conditions, but probably at the expense of a little diffuser expansion.
But that's a tricky one because if you can keep the aero more stable and drive the wing harder that will also extract from the diffuser anyway because the upwash is linked.

Basically it might be a wash on downforce but also make things less sensitive to wind, setup, aero changing under pitching, etc.

[godlameroso]

Maintaining the hulk flex analogy.

Notice how you hollow your back and exhale when you flex, and the motion of your arms is to close them.

The low pressure air is the void between your hands. If your two hands touch you can't flex your back, but if you have a nice wide gap between your hands you can flex your back like crazy.

Therefore if you can keep air from recirculating, by maintaining a nice wide gap in between the high pressure hands, the diffuser(your back) can hollow out like crazy.

The higher the rake(the further your arms are from your chest) the more your back is naturally arced.

A bird flapping its wings is doing the same thing no? By stretching its back it increases the surface area of its wings, it has to do this to force the wing tips angle of attack.

Sorry I guess I can see how it's difficult to follow so let's take a step back.

Birds have the low pressure on the top of their body, their hands are high pressure hands when they flap towards each other. F1 cars are the opposite, the underside is the low pressure, the principle however is the same. Whatever the bird does to create lift will create negative lift if the direction of travel is reversed on the bird. So you have to orient yourself that way first before any of this can make sense.

In other words whatever the bird does to create lift traveling in one vector, will create downforce if the same shape travels in the exact opposite vector. Or if the vector is the same, if the shape is inverted, it will also create negative lift.

With time and practice you can train yourself to see things this way. The aero on the car works exactly the same way, it's just an upside down inverted bird.

[Morteza]

[godlameroso]

If we apply what we've learned, we can see why if you want more cooling putting those vents there is helpful. By creating a divergent flow by the radiators, you force more air through them, much like the diffuser helps force air through the floor of the car. Like the diffuser, the divergent flow creates high pressure at the exit thus increases drag a small amount.

[BassVirolla]

this is really interesting.. anyone with a bit of expertise able to shine some light on this?

The diffuser expansion creates upwash/outwash and this new endplate design aims to make the most of this by introducing multiple elements that will produce some local load.

Divergent flow. The flaps restrict the high pressure flow from merging with the low pressure upwash of the diffuser. Remember the rotation of the vortices under the floor. The direction of the air flow and rotation in that region is TOWARDS the center of the car, not away. The diffuser flow is from the center and diverges outward in two spirals. It is moving up and out from the center, and down and in from the periphery. Imagine flexing like Hulk Hogan(by flexing like Hulk Hogan) and you'll get a feel for how the air moves out of the diffuser when looking at the rear of the car.

Learn more here.



https://files.catbox.moe/o0uosn.jpg
Here we see exactly the same rotation of the diffuser airflow on the right side of the car when seen from the rear, but explained in a macro model.

It looks like doing some extra up-wash paralel to traveling direction.

Also, I think these longitudinal slots are creating, by getting some ascending air stream from the top of the diffuser, a vortex rotating in the opposite sense of the vortex originated at the sides of the floor / diffuser, helping to seal the top of the diffuser from the air spill from behind the rear wheels and the floor / diffuser edge.

[godlameroso]

The diffuser expansion creates upwash/outwash and this new endplate design aims to make the most of this by introducing multiple elements that will produce some local load.

Divergent flow. The flaps restrict the high pressure flow from merging with the low pressure upwash of the diffuser. Remember the rotation of the vortices under the floor. The direction of the air flow and rotation in that region is TOWARDS the center of the car, not away. The diffuser flow is from the center and diverges outward in two spirals. It is moving up and out from the center, and down and in from the periphery. Imagine flexing like Hulk Hogan(by flexing like Hulk Hogan) and you'll get a feel for how the air moves out of the diffuser when looking at the rear of the car.

Learn more here.



https://files.catbox.moe/o0uosn.jpg
Here we see exactly the same rotation of the diffuser airflow on the right side of the car when seen from the rear, but explained in a macro model.

It looks like doing some extra up-wash paralel to traveling direction.

Also, I think these longitudinal slots are creating, by getting some ascending air stream from the top of the diffuser, a vortex rotating in the opposite sense of the vortex originated at the sides of the floor / diffuser, helping to seal the top of the diffuser from the air spill from behind the rear wheels and the floor / diffuser edge.

I think you're on the right path. When air is spinning in a vortex, the process is high pressure air swirling to fill the low pressure center. Once the high pressure air fills the low pressure center, the vortex dissipates, but if you delay the high pressure air from filling the low pressure, then the vortex is maintained.

There are two ways to stop air from filling the low pressure air. The first is a simple barrier, the air will move around the barrier to fill the low pressure void left by the barrier if there is a pressure difference, the endplates on a wing are a nice example. The second is more interesting, you speed the air up further. A vortex is a low pressure core, and the wall of the vortex is defined by the high pressure and low pressure regions.

If high pressure air is accelerated it becomes low pressure air, but why does it increase the strength of the vortex if that high pressure air surrounding the vortex becomes accelerated faster than the vortex? Because the viscous forces of the twist create a centrifugal torque reducing the pressure in the core of the vortex. The air circles around the vortex and instead of filling the center, it misses the center, every time the air misses the center it "pulls" the core outward, in other words creates stronger divergence.

It's like starting a lawnmower, you pull the string to spin the crankshaft, the air pulls the vortex, and it spins faster, creating lower pressure.