Red Bull Rake 2012 without EBD

[dren]

I think they will go for some radiator gases through where the exhausts go now. They could increase the flow by using a venturi on the exits (i think) and maybe some Meredith effect too (if its allowed). That could give a similar (although lesser) effect to what they have now.

Is it the temperature they need, or the mass flow of the gas?

[MIKEY_!]

It may not be enough but it may have some useful effect. Wouldn't surprise me if they have looked into it, but as someone pointed out earlier we simply can't know without some numbers to go on.

[godlameroso]

Let's look at this image, look at where the diffuser is, and where the rear wheel cascades are. It seems to me that the exhaust is surrounded by pieces of bodywork that dynamically lower pressure. The exhaust seems to be a high pressure center(remember density of air decreases as it's heated, although not it's pressure, quite the opposite really, otherwise we wouldn't be able to extract mechanical work from mixing gasoline with air and combusting it)



In this image we see Hurricane Igor, blue and purple represent higher relative pressure, orange and red, lower pressure. Notice how the eye is blue, but the area directly surrounding it is red.

I bet you could take the second image and superimpose it with the eye being placed over the exhaust in the first and it wouldn't be that far off from the truth if you could run a pressure map of the rear end of the car going 200kph at full throttle, although I doubt it would be as symmetrical.

Also look at all modern airliners, why are the exits of the turbines under the wing where the pressure is higher? Why not blow over the wing, where the pressure is low, maybe because it would cause the wing to stall?

[Sonic59]

In this image we see Hurricane Igor, blue and purple represent higher relative pressure, orange and red, lower pressure. Notice how the eye is blue, but the area directly surrounding it is red.

I bet you could take the second image and superimpose it with the eye being placed over the exhaust in the first and it wouldn't be that far off from the truth if you could run a pressure map of the rear end of the car going 200kph at full throttle, although I doubt it would be as symmetrical.

Also look at all modern airliners, why are the exits of the turbines under the wing where the pressure is higher? Why not blow over the wing, where the pressure is low, maybe because it would cause the wing to stall?

I'm not sure that we can compare giant hurricane and small exhaust vortex - they have way too different reynolds numbers.
About wing jet engine placement: they place engine under the wing to increase aerodynamic quality. If u place them over the wing - it would cause very high Cl and high max AoA. But civil aircraft dont need high Cl - they need quality.

[hardingfv32]

What about the Antonov An-72?

Brian

[Sonic59]

What about the Antonov An-72?

Brian

An-72 has very high Cl max. It was designed to allow short take off and landing distance, so it really needed high Cl.

[Dragonfly]

And is a civil version of an otherwise military plane AFAIK.

[godlameroso]

It's an exaggerated illustration

http://www.mitsubishi-motors.com/corpor ... 16E_03.pdf

While I'm using exaggerated illustrations, I thought this was neat when i read it back in the day.

[Sonic59]

It's an exaggerated illustration

http://www.mitsubishi-motors.com/corpor ... 16E_03.pdf

While I'm using exaggerated illustrations, I thought this was neat when i read it back in the day.

Thanks for the link =)

[dren]

Its true that the EBD does allow the amount of rake to be used this year. However the issues of sealing the diffuser and the problems of tyre-squirt (the air hitting the rear tyre and disrupting flow into the diffuser), all existed before 2011. If yo look at the floor area between the tyre and diffuser in pre 2010 cars, you’ll see the raised section of floor. This scoops up and directs air below the floor to act as a fluid skirt. these will be back next year, as they exploit the same 5cm of outer floor as the RBR style EBD does

Took this from a Scarbs post on his own site.

[godlameroso]

Does anyone think it possible to use vgs' as outlined in the paper to help exhaust gases reach the rear end? Heck you could take it a step further and use openings at the trailing edge of the vgs' to exit some of the internal air flow to try and maintain the temp of the exhaust as long as possible. Even though the rules mandate a periscope exhaust do we know if the exhausts have to point directly backwards, or can they be angled?

[dren]

Does anyone think it possible to use vgs' as outlined in the paper to help exhaust gases reach the rear end? Heck you could take it a step further and use openings at the trailing edge of the vgs' to exit some of the internal air flow to try and maintain the temp of the exhaust as long as possible. Even though the rules mandate a periscope exhaust do we know if the exhausts have to point directly backwards, or can they be angled?

I know the 2014 regs state the exaust outlets, of which there can only be two, have to be cylindrical in shape. Not too sure about 2012.

I'm looking for bodywork in those areas since exhaust outlet is treated as bodywork.

[hardingfv32]

How does the typical EBD exhaust outlet deal with the problem of tyre-squirt? The exhaust outlet is 50-70 cm in front of the tire and good distance above the ground. The exhaust flow would seem parallel to the ground. The air flow around the tire would seem well established below the flow of the exhaust.

Could the exhaust be forming a vortex that draws flow from below and routes it between the tire side wall and the diffuser side. How does this integrate with the hub mounted cascades?

Brian

[shelly]

The exhaust is deflected down by the vortex around the diffuser footplate. I enhances that vortex, which straightens the tyre squirt vortex

[MIKEY_!]

A previous solution for cleaning up flow around the rear tires.