My impressions: Williams Fw35: »Blown nut«
Firstly the most interesting thing is why the use separated duct (to view click link under paragraph and look deep inside this year additional curved brake duct scope)? Caliper cooling etc. There are plenty of options but anway that is not a point of my post…
Take a close look inside the duct on this foto
Klik to see a foto
I would like to show and somehow simulate how vortices exit the "hub" duct (look two pictures below) but i have no so enough knowledge and resources to accurately predict and prove the following theory. Anyway fact is that Williams introduced 2 different duct exit designs (again look Pic1 in Pic2). I guess that first version is was just some sort "confirmation" or intermediate phase of proving the blown theory. Or even more, maybe they try include in the design rotating nut to help vortices's control (especially rotation). Strange is that there are plenty of "free" of
outer space around central oval duct exit! Maybe that had some sort connection with that divided extra brake duct that i metion on the beginning.
Pic 1: Launch or "confirmation" version
Second iteration of next new nozzle exit (Pic2)is added onto whole duct assembly and covers main central oval duct witch maybe redirected vortices's more accurately (without any "wheel nut intervention")=>more controllable flow=>also flow loose less energy, cuz if you do opposite and you to much mess with the flow=> more energy is lost =>less performance you get.
Pic 2: Advanced version of duct exit
The whole impact of that vortices on the car aero-performance is very complex »stuff«. I think if we look on the CFD on the ordinary F1 tyre and LES simulation yt videos (look lower)...
Tire CFD (google)
...we could see the path tendency of the vortices's after it. In the middle of the tire we could see that vortices's after the edge woud probably push that vortices's downside (closer to the ground).
Lets look those two CFD pic, what we could see...
http://i.imgur.com/uzuOT.jpg
(this two picture are Force India's, posted somewhere by Forza)
For me is interesting that "air pocket" closer to the ground which have tendency to continue toward near rear tire and even toward floor edge (look on the vectors of the 1st picture)...
So if they get that vortices's we could with combination of front wing endplate design (deflectors) directed that vortices's toward the edge of the floor consequentially we also help to »seal« edge of the difuozor (tire skirt, look cfd pressure plot pic below).
http://1.bp.blogspot.com/-cDBGifwo74s/U ... +20m_s.bmp (google)
So the vortices's after the front left tire (camber) rotating clockwise (look down on BACK-VIEW of LES simulation )...
[youtube]
http://www.youtube.com/watch?v=UsuQVLx9lFY[/youtube]
...and clockwise wise vortices's on the left side of the cars floor are actually good (with that reason we see those
lips on the edge of the floors), but we still have very turbulent air (look down on yt).
[youtube]
http://www.youtube.com/watch?v=bsQcPNCm0_8[/youtube]
And to avoid that problem engineers put covers on the rims, but unfortunately this was baned after 2009. So the Newey first came up (i think) with blown hub to control that vortices's and get towards the floor. Williams engineers go even the step further and even more expand development in that area... So now are vortices's pretty accurately aimed toward floors.
That is complex topic and i try represent it clearly, so there for more study works, how the »brake stream« works on the tyre (ofcourse who wants to read).
http://www.aps.org/units/dfd/pressroom/ ... axerio.cfm
So Williams could do higher rake the (that the preseason test in Barcelona clearly shows, look page 22 on the bottom), car is not anymore vulnerable for »side-winds«, higher downforce etc. Ohh wait irony
, maybe is that sys even more complex to configure like i thought and there lies "main" problem on mysterious problems in bad rear handling.. Maybe they need just little tweak (easy to say..) to reset whole disharmony between endplate, suspension, flow deflectors etc.
But dont forget the whole efect during steering the tyre could change the things i little bit, but I would not like to speculate, because (also i hate that word) i don't have the any aero tools and enough knowledge to predict it. Maybe anybody else can? What you think?
And thanks everyone for pics etc.
"And if you no longer go for a gap that exists, you're no longer a racing driver..." Ayrton Senna