Open ended questions about exhausts and downforce

[Cam]

I can verify Olefud's point because when studying hurricane formation one notices that it is primarily the sun and ambient temperature plus humidity that creates a large mass of steaming sea water. All this hot water wants to rise, and rise fast it does, and as it rises it carries heat with it, and this heat rushes upward in order to fulfill it's desire for equilibrium. Sometimes the mass is too much for it to equalize and balance out as mere rain because the constant high pressure weather system keeps feeding sunlight to this steaming pile of seawater. This mass is so large and requires so much negative delta of temperature and pressure to balance it out that it almost reaches the mesosphere. The pressure wake that results from this act of equilibrium is those spinny things of death we call hurricanes.

The point of all this is that heat is a very good way of creating increased flow, increased flow equals greater pressure differential on any exposed surface. Heck you just need a loosely organized weather system to keep a hurricane together(which is why hurricanes are steered so easily by low and high pressure systems), and F1 cars have a discrete surface attempting to organize flow (freaking bodywork). I wonder when teams will get to the point of trying different textures on different parts of the car to further influence flow and vorticity generation(Kind of like how textures(topography) on earth's surface affect hurricanes).

That's a nice point about different textures - so its possible (viable?) to speed up/slow down flow to increase aero performance on an F1 car? Could you actually use textured air (turbulence) to create a similar effect?

[godlameroso]

You could possibly texture certain parts of surfaces, and it would definitely affect how air is distributed across that surface. You could use a rough texture in certain parts of the wing where there are attachment problems under yaw, and smoother textures towards the center span where air tends to be more undisturbed. Just a thought.



*edit http://jeb.biologists.org/content/203/20/3125.full.pdf
**edit: a rougher surface can aid flow attachment under a normally stalling condition because the textured surface essentially shrinks the surface area that the statistically significant flow encounters, essentially doing more with less, that is making the surface smaller decreases the probability of detachment, with a slight down force penalty. Of course all this would have to be designed as a system but it could introduce a new tuning parameter.

But meh, sometimes it's better to just be simple.

[jamsbong]

I just found these explanations from Enrique Scalabroni on youtube.
You've gotta admire his ability to draw and illustrate. Moreover, his ability to explain air flow is way better than I can do it and I'm a CFD engineer. LOL...

[youtube]http://www.youtube.com/watch?v=WiNi5eyJEEo[/youtube]

[youtube]http://www.youtube.com/watch?v=DVHR8_B7bfg[/youtube]

[youtube]http://www.youtube.com/watch?v=gryojy2cHnI[/youtube]

[youtube]http://www.youtube.com/watch?v=xqh01JhEjMU[/youtube]

[Tommy Cookers]

+1 for the stuff on roll centres and scrub ........ thanks all round !