After sometime (we're talking months here) I've finally got round to doing a little explaining on some of the main aero developements which have appeared this season.
Some of the information contained within this thread comes from this week's guest publication: Bernoulli (Aerodynamics International) - "The science of flying on the ground"
So lets get things started with....
Ferrari's "Nose hole"
When rumours of the hole in Ferrari's nose first came out I was very sceptical, mainly because the descriptions of how it worked, well... just didn't.
How they said it worked:
The original description was that air passing over the front wing (specifically the flap) normally gets caught under the nose, causing a high pressure area. The nose hole would then release this air through the nose.
(descriptions like: F1-Technical)
Now if we go back to basic aerodynamics, a wing works by creating a pressure difference between the upper and lower surfaces.
In the case of an F1 wing, higher pressure on the top, lower on the bottom - thus creating downforce.
Surely then, having a really high pressure area on the nose is a good thing, and releasing it would actually reduce downforce!
In fact, deliberately causing a blockage to the air going over the wing is widely used to gain downforce by many teams by almost joining the flap to the underside of the nose.
How it really works:
So after a little though, a few conversations with some people who understand such things and a read of the above mentioned magazine it makes alot more sense if the nose hole works basically the other way round.
The issue with a normal nose is that air coming off the underside of the wing flap hits the nose (and other components) and creates an area of higher pressure - which slightly cancels out the higher pressure on top of the wing - reducing downforce.
If you allow this air to flow through the nose, then you reduce the pressure under the wing further - working the centre of the wing harder, creating more downforce.
If you have more downforce generated by the centre of the wing, you can back-off the sides of the wing and reduce the upwash - which takes air away from the underbody of the car.
Looking at a side view of the Ferrari nose, the bottom of the nose hole is visable as a small scoop... which definately appears to be too far back on the nose to be taking air from infront of the flap.
What are the downsides?
Well appart from not being able to use it everywhere, the main problem is the FIA crash test.
As Williams found with the "Walrus" of 2004, making the nose into two side beams makes the challenge of passing the front impact test that much harder. That said, any additional weight in the nose may actually help with the weight distribution required by the current tyres.
The hole will also create a certain amount of drag and turbulence. This turbulent air will mainly hit the driver in the face (not a huge concern to the aero guys) and some will enter the airhorn in the roll-hoop. It is therefore possible that the engine performance could be affected, and this concern is definately backed up by Ferrari running a series of Pitot tubes (to measure pressue) in front of the airhorn during testing of the new nose.
So why don't they use it everywhere?
Well basically if you run low downforce, you back-off the wings.
Backing off the front wing means lowering the flap.... which pulls it away from the underside of the nose.
If you had the nose hole with this wing layout, air from above the flap would pass through the nose.... and we're back to the original point of actually reducing the effectiveness of the wing.
This is why the nose hole is only used at higher downforce tracks.
Next time....
Dorsal fin engine covers (aka "Shark Fins")
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Great stuff 
Originally Posted by Greig
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