McLaren MCL33

[henry]

Motorsports says top speed issue is due to gearbox ratios. Not sure how true but it would make sense a bit.

Their gear ratios are same as others. They used to vary in the N/A era, not now.

Is the dif ratio fixed? I know the actual gear steps are, but overall gearing can be lengthened at the dif?

The number of ratios is fixed at 8

They can choose any ratios they like at the beginning of the season. Thereafter they may not change them. They could make one change in 2014 and 2017 in case their initial choice didn’t match their actual vehicle performance.

@hollus had excellent threads on the ratio choices in both years, here’s one. viewtopic.php?f=4&t=26230&p=689648&hili ... rd#p689648

[Vanja #66]

But any air that passes through the mid-wing to go towards the diffuser won't be as strong as the tea-tray extension, which disappeared when the nose cape was introduced. It cannot be a coincidence.

Everything that goes under the nose and between vertical barge boards and chassis ends up under the floor. That's why teams use various scoops and vanes starting from the tip of the nose all the way down to vertical barge boards to guide that air under the nose and towards the splitter. More air means more mass flow, meaning higher velocity, meaning lower pressure, meaning suction and introducing a bit more air to be guided under the floor.

Everything that goes 50+mm outboard from barge boards goes away from the floor, this includes y250 vortex and very likely nose cape vortex as well (if it even survives that long, which doesn't look too convincing). This air is disturbed by front tyre wake and front suspension, has very low energy and so is practically useless.

What you stated is true, tee-tray extensions behind barge boards are important, they are used to make downforce and, again, guide more air under the floor. However, as I said before, vortices are total pressure killers and you don't want to introduce one that was formed more than a meter upstream under the floor, as it would negatively affect diffuser performance.

The vortex formed by lower end of vertical barge boards looks to be extending to the floor edge vortex, enhancing their sealing effect. The vortex formed by upper end of vertical barge boards ends up above the floor, therefore pulling air around it and guiding it above the floor. This later translates to more air in coke bottle zone, improving diffuser performance.

Why was vortex stretching under the floor such a thing with the 06-08 cars then? The stair-stepped leading edge of the floor seems counter intuitive to what you are saying...

Rules were different, diffusers were deeper and more aggressive, so they could work the air even if it didn't have as much energy, so teams used long vortices to lower the pressure and didn't concern themselves with energy that much. Other than that, floors were narrower and shorter and overall downforce from the floor and diffuser was less than 50%. Now it's over 60%.

[Big Tea]

Their gear ratios are same as others. They used to vary in the N/A era, not now.

Is the dif ratio fixed? I know the actual gear steps are, but overall gearing can be lengthened at the dif?

The number of ratios is fixed at 8

They can choose any ratios they like at the beginning of the season. Thereafter they may not change them. They could make one change in 2014 and 2017 in case their initial choice didn’t match their actual vehicle performance.

@hollus had excellent threads on the ratio choices in both years, here’s one. viewtopic.php?f=4&t=26230&p=689648&hili ... rd#p689648

Thanks, that was good.
So much good stuff in old posts I will have to spend more time trawling.

[diffuser]

They should ask permission to change Gear ratios since they change PUs last year. Little late now or unless they don't think it will make that much of a difference.

[M840TR]

But any air that passes through the mid-wing to go towards the diffuser won't be as strong as the tea-tray extension, which disappeared when the nose cape was introduced. It cannot be a coincidence.

Everything that goes under the nose and between vertical barge boards and chassis ends up under the floor. That's why teams use various scoops and vanes starting from the tip of the nose all the way down to vertical barge boards to guide that air under the nose and towards the splitter. More air means more mass flow, meaning higher velocity, meaning lower pressure, meaning suction and introducing a bit more air to be guided under the floor.

Everything that goes 50+mm outboard from barge boards goes away from the floor, this includes y250 vortex and very likely nose cape vortex as well (if it even survives that long, which doesn't look too convincing). This air is disturbed by front tyre wake and front suspension, has very low energy and so is practically useless.

What you stated is true, tee-tray extensions behind barge boards are important, they are used to make downforce and, again, guide more air under the floor. However, as I said before, vortices are total pressure killers and you don't want to introduce one that was formed more than a meter upstream under the floor, as it would negatively affect diffuser performance.

The vortex formed by lower end of vertical barge boards looks to be extending to the floor edge vortex, enhancing their sealing effect. The vortex formed by upper end of vertical barge boards ends up above the floor, therefore pulling air around it and guiding it above the floor. This later translates to more air in coke bottle zone, improving diffuser performance.

Why was vortex stretching under the floor such a thing with the 06-08 cars then? The stair-stepped leading edge of the floor seems counter intuitive to what you are saying...

Rules were different, diffusers were deeper and more aggressive, so they could work the air even if it didn't have as much energy, so teams used long vortices to lower the pressure and didn't concern themselves with energy that much. Other than that, floors were narrower and shorter and overall downforce from the floor and diffuser was less than 50%. Now it's over 60%.

Thanks for clarifying. But there's still one point unclear. If there's a cavity in the mid-wing area, wouldn't the nose vortex end up under the floor as well since that area is in its travel path? And why is it you think it might not be a strong vortex?

[M840TR]

Any clear pictures of the ripped open nose? The crash might have exposed some of the internal ducting.

This high-res photo shows the mid-duct opens underneath the cape and guides air to the tea-tray.

[Vanja #66]

Thanks for clarifying. But there's still one point unclear. If there's a cavity in the mid-wing area, wouldn't the nose vortex end up under the floor as well since that area is in its travel path? And why is it you think it might not be a strong vortex?

That vortex doesn't seem strong since the surfaces that cause it to form are very flat, even though there is a "slot" now formed with new turning vane design.



Photos aren't great, but I don't see a lot of flow sidewash on turning vanes that would suggest a big pressure difference causing a vortex to form. I've done a CFD sim of Mercedes cape and that vortex wasn't very strong at all.

Y250 is much stronger in any case and they are counter-rotating, so this would suggest Y250 would be drawing cape vortex towards it. And Y250 ends up outboard anyway.

This high-res photo shows the mid-duct opens underneath the cape and guides air to the tea-tray. https://i.redditmedia.com/_kFwLKS-nXp1O ... deb0e82098

Awesome find. Are we sure that it's only mid duct? Looks like all three ducts could go to that single one under the cape.

[F1NAC]

Thanks for clarifying. But there's still one point unclear. If there's a cavity in the mid-wing area, wouldn't the nose vortex end up under the floor as well since that area is in its travel path? And why is it you think it might not be a strong vortex?

That vortex doesn't seem strong since the surfaces that cause it to form are very flat, even though there is a "slot" now formed with new turning vane design.

https://pbs.twimg.com/media/DlXlxy8XoAcfnpT.jpg:large

Photos aren't great, but I don't see a lot of flow sidewash on turning vanes that would suggest a big pressure difference causing a vortex to form. I've done a CFD sim of Mercedes cape and that vortex wasn't very strong at all.

Y250 is much stronger in any case and they are counter-rotating, so this would suggest Y250 would be drawing cape vortex towards it. And Y250 ends up outboard anyway.

This high-res photo shows the mid-duct opens underneath the cape and guides air to the tea-tray. https://i.redditmedia.com/_kFwLKS-nXp1O ... deb0e82098

Awesome find. Are we sure that it's only mid duct? Looks like all three ducts could go to that single one under the cape.

A bit OT but what CFD program are you using? OpenFoam or Ansys?

[M840TR]

Thanks for clarifying. But there's still one point unclear. If there's a cavity in the mid-wing area, wouldn't the nose vortex end up under the floor as well since that area is in its travel path? And why is it you think it might not be a strong vortex?

That vortex doesn't seem strong since the surfaces that cause it to form are very flat, even though there is a "slot" now formed with new turning vane design.

https://pbs.twimg.com/media/DlXlxy8XoAcfnpT.jpg:large

Photos aren't great, but I don't see a lot of flow sidewash on turning vanes that would suggest a big pressure difference causing a vortex to form. I've done a CFD sim of Mercedes cape and that vortex wasn't very strong at all.

Y250 is much stronger in any case and they are counter-rotating, so this would suggest Y250 would be drawing cape vortex towards it. And Y250 ends up outboard anyway.

This high-res photo shows the mid-duct opens underneath the cape and guides air to the tea-tray. https://i.redditmedia.com/_kFwLKS-nXp1O ... deb0e82098

Awesome find. Are we sure that it's only mid duct? Looks like all three ducts could go to that single one under the cape.

It's interesting. Previously I thought as well that the y250 and the nose vortex might be merging together but I wasn't sure they were counter rotating. My theory was, both vortexes due to this end up in the diffuser instead of managing the tyre wake and consequently cause an aerodynamic stall. But that was before the path and energy of the nose vortex became clear.

I think it's likely only the middle duct that ends up in this opening. It would make much more sense that the other create low pressure air underneath the sides of the cape to energize the vortex. They seem separate from this angle for sure.

[charliesmithhd]

Thanks for clarifying. But there's still one point unclear. If there's a cavity in the mid-wing area, wouldn't the nose vortex end up under the floor as well since that area is in its travel path? And why is it you think it might not be a strong vortex?

That vortex doesn't seem strong since the surfaces that cause it to form are very flat, even though there is a "slot" now formed with new turning vane design.

https://pbs.twimg.com/media/DlXlxy8XoAcfnpT.jpg:large

Photos aren't great, but I don't see a lot of flow sidewash on turning vanes that would suggest a big pressure difference causing a vortex to form. I've done a CFD sim of Mercedes cape and that vortex wasn't very strong at all.

Y250 is much stronger in any case and they are counter-rotating, so this would suggest Y250 would be drawing cape vortex towards it. And Y250 ends up outboard anyway.

This high-res photo shows the mid-duct opens underneath the cape and guides air to the tea-tray. https://i.redditmedia.com/_kFwLKS-nXp1O ... deb0e82098

Awesome find. Are we sure that it's only mid duct? Looks like all three ducts could go to that single one under the cape.

It's interesting. Previously I thought as well that the y250 and the nose vortex might be merging together but I wasn't sure they were counter rotating. My theory was, both vortexes due to this end up in the diffuser instead of managing the tyre wake and consequently cause an aerodynamic stall. But that was before the path and energy of the nose vortex became clear.

I think it's likely only the middle duct that ends up in this opening. It would make much more sense that the other create low pressure air underneath the sides of the cape to energize the vortex. They seem separate from this angle for sure.

https://i.imgur.com/jML11mT.jpg

https://i.imgur.com/wEpry4I.jpg

Why isn't there any curvature on the cape? It looks quite basic.

[M840TR]

That vortex doesn't seem strong since the surfaces that cause it to form are very flat, even though there is a "slot" now formed with new turning vane design.

https://pbs.twimg.com/media/DlXlxy8XoAcfnpT.jpg:large

Photos aren't great, but I don't see a lot of flow sidewash on turning vanes that would suggest a big pressure difference causing a vortex to form. I've done a CFD sim of Mercedes cape and that vortex wasn't very strong at all.

Y250 is much stronger in any case and they are counter-rotating, so this would suggest Y250 would be drawing cape vortex towards it. And Y250 ends up outboard anyway.



Awesome find. Are we sure that it's only mid duct? Looks like all three ducts could go to that single one under the cape.

It's interesting. Previously I thought as well that the y250 and the nose vortex might be merging together but I wasn't sure they were counter rotating. My theory was, both vortexes due to this end up in the diffuser instead of managing the tyre wake and consequently cause an aerodynamic stall. But that was before the path and energy of the nose vortex became clear.

I think it's likely only the middle duct that ends up in this opening. It would make much more sense that the other create low pressure air underneath the sides of the cape to energize the vortex. They seem separate from this angle for sure.

https://i.imgur.com/jML11mT.jpg

https://i.imgur.com/wEpry4I.jpg

Why isn't there any curvature on the cape? It looks quite basic.

Depends upon the intended travel path of the vortex. A curvature won't make it complex, just change the philosophy a bit.

[Thunder]

https://twitter.com/ScarbsTech/status/1 ... 9738594304

Also i moved the Post abour the Renault Upgrade to the Team Thread.

[Chicane]

A higher resolution image of the new front wing.

[charliesmithhd]

A higher resolution image of the new front wing.

https://pbs.twimg.com/media/Dl1LIZ5W4AEhRCr.jpg

Good to see these straight line improvements rather than keeping a relatively high downforce package

[M840TR]

https://twitter.com/ScarbsTech/status/1 ... 9738594304

Also i moved the Post abour the Renault Upgrade to the Team Thread.

Doesn't necessarily mean a skinnier rear wing but still excited to see what they'll run.