Red Bull RB7 Renault

[hardingfv32]

1) "Looks like...." What, the RB shown in the last photo?

2) "absolutely perfect for the air to stay attached" May I assume we are talking about staying attached to the RB side pod?

So I repeat my question: At what vehicle speed or range of speeds?

3) If the rain drop is such a perfect shape, why not use it at the nose?

Brian

[Robbobnob]

Dont get me wrong, but i assume Red Bull have gone to lengths to ensure that the flow stays attached through the rear of their car.

Without running and CFD on the potential shapes of the car once cannot be certain, so it really is a difficult question to answer.

Plus the geometry of the car would make it impractical to run such a shape for the nose, as the body thickens towards the driver.

[beelsebob]

1) "Looks like...." What, the RB shown in the last photo?

2) "absolutely perfect for the air to stay attached" May I assume we are talking about staying attached to the RB side pod?

So I repeat my question: At what vehicle speed or range of speeds?

3) If the rain drop is such a perfect shape, why not use it at the nose?

Brian

1) yes
2) yes
2.1) This shape works well at all speeds – that's why a rain drop doesn't change shape much as it falls (and accelerates).
3) Because their aim when designing the nose is not to make the most efficient shape through the air that provides the cleanest flow behind it. Instead, their aim is to direct air to various places around the car, and to make a safe space for the drivers feet/the suspension.

[hardingfv32]

We know there is a lot of redirected front wheel flow developed by the front wing. A CFD clip I viewed indicated that this flow arced around and blended in well with the rear half of the side pod shape.

Brian

[godlameroso]

Again that wall of airflow around the rear of the side pods, and the rake of the car, in conjunction with the engine exhaust, and hot air from the cooling system creates an isolated low pressure zone surrounded by a wall of relatively higher pressure air caused by the chassis conditioning said airflow. This causes a vortex to be formed behind the car, and works to generate more downforce than the diffuser or wings could alone.

[ringo]

Viewing the highly curved RB side pods in the above photo:

What is the nature or quality of the air flow around the side pod? It seems too round to stay attached. Would the quality of attachment stay the same as speed/flow increases?

I don't understand why the flow would want to move towards the top of the transmission.

Brian

The rear wheels are the reason why they do that at the rear. You want that channel between gear box and wheel to be as wide as to be as unrestrictive as possible.
It will stay attached because it's flowing from the side and top at the same time.
If you look at it in 2 dimensions it wont seem like it will stay attached.
If you look on two streams in 3d , one over the top, one at the side that converge, then it easier to see why it stays attached.

[Formula None]

Yeah, the sidepods on the RB7 are tapering not just on the sides, but from top to bottom. I agree the form isn't as truncated as it seems.

And not to be pedantic, but the raindrop shape is a myth. They are always pretty much a spheroid shape, due to surface tension and being liquid, the high pressure zone at the leading edge tends to push into those spheres at speed and break apart the larger drops.

[HampusA]

The only time raindrops actually form like the myth says is for example when it falls of a leave

Here´s raindrops, real ones,

http://www.wallpaper4me.com/images/wall ... 44449.jpeg

2.1) This shape works well at all speeds – that's why a rain drop doesn't change shape much as it falls (and accelerates).

It´s water, it moves around all the time.

[rayden]

raindrops are perfectly round - not tear drop shaped.

edit: oops, must remember to read thread till end

[Jeffsvilleusa]

While investigating the purpose of the hole in the rear of the bodywork of the Ferrari (and Red Bull), I came across this article by scarbs, where he notes that the absence of bodywork at the rear of the car is a clear advantage:

If you look at the RB7s sidepods, from the radiators back they appear to slope away to nothing. This leaves the distinctive flat floor and open area ahead of the rear wheels. This creates an obvious aero gain, but how is cooling achieved with such a tight design?

from http://scarbsf1.wordpress.com/2011/02/1 ... d-cooling/

So how is having 'naked floor' at the rear an obvious aero gain?

[PhillipM]

Feeds cleaner air over the beam wing, rear wing and diffuser/'brake cooling' fins...

[TheWiseOwl]

And not to be pedantic, but the raindrop shape is a myth. They are always pretty much a spheroid shape, due to surface tension and being liquid.

+1

A sphere gives the minimum possible surface area and hence the lowest energy structure.


The minimum possible surface area isn't what you necessarily want when creating downforce, though.

[avatar]

TheWiseOwl:
Not sure if I've understood the "sphere is the lowest energy structure" bit.

If you mean the most structurally efficient [enclosed] arrangement, then that makes sense.
If you mean the best for aero, in a teardrop shape vs a sphere contest, a teardrop should be more aero efficient in 1 direction; less frontal area (for same volume) & less turbulence at the rear as the flow remains attached on both sides (*), merging (relatively) smoothly at the rear.



(*)(2 sides as in an f1 layout)

[HampusA]

The reason water get´s spherical.. Isn´t that simply down to our atmosphere pulling it together?
And really not because it´s the most efficient aero solution? (even though it might be, i don´t know)

[aral]

The best way to ascertain the most efficient shape, is to refer to fluid dynamics in its purest form. Newey was involved in, or interested in Americas Cup design. If you look at the keels of these boats, they are teardrop shaped, with the rounded shape to the front.
Also, if you refer to larger ships, the provision of bulbous protruberances at the front, assisted in water flow around the hull, making the craft faster, and more economical. It is mainly to do with the reattachment of the waterflow at the rear of the solid intrusion.