Scuderia Ferrari SF16-H

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter does not belong here.
turbof1
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Re: Scuderia Ferrari SF16-H

Post by turbof1 » Wed Nov 09, 2016 9:36 pm

Pierce89 wrote:
bhall II wrote:
With this new setup decluttering the rear of the SF16-H, the air can flow through a widened furrow in the car floor. That way, it can go across the entire width of the diffuser (see middle picture with the pressure sensors used to measure how efficient the diffuser is). The tighter the back of a car is, the faster the air flows above the diffuser, which in turn contributes towards sucking more air from underneath the car in conjunction with the diffuser.
That's either a myth that refuses to die or I'm just flat-out wrong about diffusers. Let's assume the latter.

http://stefanontech.weebly.com/uploads/ ... 5_orig.jpg

In terms of the fluid mechanics, does anyone understand how accelerating air flow over the diffuser is beneficial?

By extension, should we be concerned about the mental well-being of the so-called "engineers" who were responsible for McLaren's mushroom suspension? If the diffuser logic is true, not only was the original design recklessly ill-considered, the steps taken to make it work were inexplicably stupid.

http://i.imgur.com/qJDc5xJ.jpg
http://i.imgur.com/8KMc1Mb.jpg

And what about the "designers" who still insist upon these things, whatever they're called?

http://i.imgur.com/mlGcgs9.jpg

From my perspective, accelerating air over the diffuser seems like just about the last thing you'd want to do.

Anyone?
I'm pretty sure it has to do with the high energy topside side flow entraining the lower energy diffuser flow to increase mass flow through the venturi system.
Ehm no, you don't want that since you actually need some interaction between high pressure flow on top with low pressure flow at the diffuser mouth. This enhances downforce through vortex creation inside the diffuser.

https://www.linkedin.com/pulse/how-do-m ... illem-toet

If I had to guess, the "uncluttering" is more about creating laminar flow. flow in that region is prone to create quite a bit of boundary layer due the sidepods. it'll lead to reduced flow over the diffuser. You want as much as mass flow over the diffuser as slow as it can be. Sounds contradictory, I know, but that looks the reason to be for me.
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Pierce89
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Re: Scuderia Ferrari SF16-H

Post by Pierce89 » Thu Nov 10, 2016 2:22 am

turbof1 wrote:
Pierce89 wrote:
bhall II wrote: That's either a myth that refuses to die or I'm just flat-out wrong about diffusers. Let's assume the latter.

http://stefanontech.weebly.com/uploads/ ... 5_orig.jpg

In terms of the fluid mechanics, does anyone understand how accelerating air flow over the diffuser is beneficial?

By extension, should we be concerned about the mental well-being of the so-called "engineers" who were responsible for McLaren's mushroom suspension? If the diffuser logic is true, not only was the original design recklessly ill-considered, the steps taken to make it work were inexplicably stupid.

http://i.imgur.com/qJDc5xJ.jpg
http://i.imgur.com/8KMc1Mb.jpg

And what about the "designers" who still insist upon these things, whatever they're called?

http://i.imgur.com/mlGcgs9.jpg

From my perspective, accelerating air over the diffuser seems like just about the last thing you'd want to do.

Anyone?
I'm pretty sure it has to do with the high energy topside side flow entraining the lower energy diffuser flow to increase mass flow through the venturi system.
Ehm no, you don't want that since you actually need some interaction between high pressure flow on top with low pressure flow at the diffuser mouth. This enhances downforce through vortex creation inside the diffuser.

https://www.linkedin.com/pulse/how-do-m ... illem-toet

If I had to guess, the "uncluttering" is more about creating laminar flow. flow in that region is prone to create quite a bit of boundary layer due the sidepods. it'll lead to reduced flow over the diffuser. You want as much as mass flow over the diffuser as slow as it can be. Sounds contradictory, I know, but that looks the reason to be for me.
Unless you're further along on your aeronautical engineering degree than I am, or you work in an f1 team, then I'm not sure I agree. I know you want high energy flow to sneak around the footplates otherwise the edge vortices would be very weak, but I'm also pretty sure high.energy flow across the top center will perform flow entrainment on the lower engery flow exiting closer to the center of the diffuser increasing mass flow through the underbody which would also increase velocity through the underbody and increase the pressure differential. Also increased flow across the top would further activate the aerofoils that have replaced gurneys atop the diffuser and lower static pressure at the diffuser exit.
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Re: Scuderia Ferrari SF16-H

Post by bhall II » Thu Nov 10, 2016 6:37 am

I just can't see it. That doesn't mean it's not there. But, to me, it makes a whole lot more sense to direct as much air flow as possible along the flanks of the diffuser in order to strengthen the edge vortices. It offers the potential for the same effect - and then some - without compromising expansion.

Image

Naturally, correlation doesn't equal causation. But you gotta admit: the geometry of it all does seem particularly well-suited for increasing vorticity.

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Re: Scuderia Ferrari SF16-H

Post by godlameroso » Thu Nov 10, 2016 6:16 pm

In fact with the brake duct winglets it almost looks like a bird about to swoop down.

Image
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CBeck113
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Re: Scuderia Ferrari SF16-H

Post by CBeck113 » Thu Nov 10, 2016 9:18 pm

I'll try to explain this the simple way: what causes drag on a car? It is the pressure difference between the front (high pressure - you're displacing all the air there) and the rear (you've created an air hole, which is actually working with the high pressure to push the car backwards). The problem is that the low pressure behind the vehicle also tends to be very turbulent, creating uneven areas of higher and lower pressure. The diffusor works by decreasing the speed of the air flow passing through it, which also leads to a pressure increase at its mouth. So, if you improve the flow quality and increase the energy over the diffusor, you are actually increasing its volume by delaying the interaction of the two air flows (pressure gradient and flow speed delta).
The McLaren solution was more extreme: create a low pressure pocket to extract air from the diffusor. It did that, but caused a "slight" drag increase versus the more elegant air flow tailoring solutions of Merc, RB and Ferrari.

Did that make any sense :?:
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Re: Scuderia Ferrari SF16-H

Post by godlameroso » Thu Nov 10, 2016 9:39 pm

I think it helps reminding people how air is very conceited and always full of itself. And will move anything in it's way in it's self centered quest to always be full of itself. I guess existing in a pressurized gas atmosphere makes that a given. This is a little hint that makes aero work kind of obvious.
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Re: Scuderia Ferrari SF16-H

Post by wuzak » Fri Nov 11, 2016 1:17 am

bhall II wrote:I just can't see it. That doesn't mean it's not there. But, to me, it makes a whole lot more sense to direct as much air flow as possible along the flanks of the diffuser in order to strengthen the edge vortices. It offers the potential for the same effect - and then some - without compromising expansion.

http://i.imgur.com/ryGTfUb.jpg

Naturally, correlation doesn't equal causation. But you gotta admit: the geometry of it all does seem particularly well-suited for increasing vorticity.
The bit you've circled no doubt enhances the vortices used for sealing the diffuser, but between those areas on each side the spoilers/aerofoils on top of the diffuser appear to direct the air upwards, away from the diffuser exit, presumably to create that low pressure zone behind the diffuser for better performance.

I also note that the spoilers fitted under the crash structure are curved such that the air may be directed around the crash structure on its way up.

If it was just a matter of getting the vortices to work for sealing then would the rear ends end up being so tightly packaged?

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Re: Scuderia Ferrari SF16-H

Post by bhall II » Fri Nov 11, 2016 3:09 pm

The circle was already on the picture when I got to it.
wuzak wrote:If it was just a matter of getting the vortices to work for sealing then would the rear ends end up being so tightly packaged?
Yes. Increasing topside air flow along the flanks of the diffuser boosts the high-pressure component to the diffuser's edge vortices. That makes them stronger, because it widens the pressure differential between air flow above and below the floor. Stronger edge vortices allow you sustain higher rake angles for more downforce, or you can chase greater consistency, like Mercedes.

It's not sealing; it's force enhancement.

Follow the low pressure...

Image
SF15-T

EDIT: I'm not saying there's only a single goal here. I just disagree with the article from the previous page.

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Re: Scuderia Ferrari SF16-H

Post by Blackout » Fri Nov 25, 2016 8:13 am