F1technical.net

mini696 wrote:The narrow nose has little to do with downforce. I suggest the narrow nose actually helps with it, by having a larger area of undisturbed air above the front wing. The narrow nose also goes hand-in-hand with the no-keel setup, by 'opening' up the surrounding area.

The fat noses create a more 'stable' front end.

You sure?

I'd have imagined the wide front nose made more downforce by greater momentum exchange over the nose. The downforce created by the wing is relatively insensitive to the small amount of blockage made by the nose. Proof => Williams hopeless walrus nose.

I was amazed to find my AX is more aerodynamic than an F1 car at low downforce settings, whereas a Lamborghini Diablo is a long long way up the list. The most aerodynamic road car used to be a Citroen GSA, which frankly looks like it might have been driven into a wall at some point. Check this out:http://en.wikipedia.org/wiki/Drag_coefficient

I just flow short over the page but I think there could come a
few things in confusion.

Drag coefficient: a number which says how much drag a special kind
of shape makes.

Frontal area

The air resistance: the product of Drag coefficient, Frontal area,
velocity and a fixed number.

aerodynamic efficiency: downforce/air resistance


So now you can say your Citroen, or what ever, has the lowest drag coefficient but the Lamborghini has a lower frontal area.
So the Lamborghini will maybe have a lower air resistance
than your aerodinamical Citroen.
A F1 car will for sure have a much bigger air resistance but it also creates
much more downforce so the F1 car has the best aerodynamic efficiency
in our comparison.
So the Citroen is far away from beeing the most aerodynamic(aerodynamic efficienct) car.
The sport cars compare their air resistance with a powerfull engine.

I'm more confused now.

The GSA had, for a long time, the lowest drag of any road car, although i think the Vauxhall/Opel Calibra now holds that record, a Lamborghini, which anyone down the pub will tell you is super aerodynamic, actually has very high drag, partly due to large frontal area. An F1 car, with all its cooling ducts etc has quite high drag, 0.7 even on low downforce settings.

The point I'm trying to make is that although supercars and sports cars look sleek and streamlined they really aren't, you cannot see drag so no one knows what will be aerodynamic without a windtunnel or computer sofware. Sure you can make an educated guess if you've been to university and studied the stuff but a layman would not know.

Car designers rarely take into acount aero but go on what looks best. The Austin Allegro was famouse for being more streamlined in reverse (as well as for having a square steering wheel) but in reallity most cars are because aerodynamics doesn't sell cars, the people who buy them would not understand, so they are sold on looks.

kilcoo316 wrote:

mini696 wrote:The narrow nose has little to do with downforce. I suggest the narrow nose actually helps with it, by having a larger area of undisturbed air above the front wing. The narrow nose also goes hand-in-hand with the no-keel setup, by 'opening' up the surrounding area.

The fat noses create a more 'stable' front end.

You sure?

I'd have imagined the wide front nose made more downforce by greater momentum exchange over the nose. The downforce created by the wing is relatively insensitive to the small amount of blockage made by the nose. Proof => Williams hopeless walrus nose.

Nope... I'm not sure, but I guess it all depends on the 'package'.

I can see what you mean about the greater momentum change on the fat noses.

Off topic: Who is going to design next years mclaren.

Tom wrote:The point I'm trying to make is that although supercars and sports cars look sleek and streamlined they really aren't, you cannot see drag so no one knows what will be aerodynamic without a windtunnel or computer sofware. Sure you can make an educated guess if you've been to university and studied the stuff but a layman would not know.

Car designers rarely take into acount aero but go on what looks best. The Austin Allegro was famouse for being more streamlined in reverse (as well as for having a square steering wheel) but in reallity most cars are because aerodynamics doesn't sell cars, the people who buy them would not understand, so they are sold on looks.

All IIRC :

The evolution of road car aerodynamics had 3 distinct phases.

The first was "if it looks right", so cars had big smooth fairings etc [1930s or so], unfortunately this didn't work, as the rear of the car tended to slope down at around 30 degrees, which is near the worst angle (approx 32 is worst IIRC) for formation of 2 longitudinal vortices which have high drag). This phase of mainstream car design tried to incorporate fashion and design, but the design knowledge wasn't up to it.

Some aircraft manufactuers, notably rumpler made cars with real low Cd figures, but they weren't fashionable:




The next phase was detail design [1980s or so], getting things such as windows flush with the frames, doors sealing better, closer fits between panels etc. This went along way to reducing drag figures.

The final (and current) phase is incorporating detail design with careful windtunnel tests to subtly adapt fashion driven [although with most of todays cars you could argue over the fashion bit!] designs to improve their aerodynamics. By adding flatter floors, packing exhausts, suspensions better, the underfloor drag is reduced, leading to better Cd figures.

I'm not quite sure what IIRC means but I guess that you're saying I'm wrong

I doubt even Ferrari use windtunnels when designing road cars, they cost far too much, and anyway, since the late 80s all cars have been the same really, a simple 2 or 3 box design with different curves on the bod work. I agree that alot has been done to the underfloor but I think that has more to do with making it look neat, making it accesible to work on and crash safety than aero.

Tom wrote:I'm not quite sure what IIRC means but I guess that you're saying I'm wrong

I doubt even Ferrari use windtunnels when designing road cars, they cost far too much, and anyway, since the late 80s all cars have been the same really, a simple 2 or 3 box design with different curves on the bod work. I agree that alot has been done to the underfloor but I think that has more to do with making it look neat, making it accesible to work on and crash safety than aero.

IIRC = If I Recall Correctly.


No, your previous post wasn't wrong at all, except perhaps the implication Lambo's main drawback is its frontal area - all those sharp corners are very bad for the Cd figures as well.

Car design is dominated by fashion [although I think most modern cars look ---, with the except of the new honda civic, I think its the dogs balls!]


Unfortunately, the post I've quoted is wrong in saying car manufacturers don't use windtunnels when designing cars, they most certainly do, alot of work goes into it.

Tom wrote:I'm not quite sure what IIRC means but I guess that you're saying I'm wrong

I doubt even Ferrari use windtunnels when designing road cars, they cost far too much, and anyway, since the late 80s all cars have been the same really, a simple 2 or 3 box design with different curves on the bod work. I agree that alot has been done to the underfloor but I think that has more to do with making it look neat, making it accesible to work on and crash safety than aero.

Ferrari uses the windtunnel for all there cars... look at the diffusers and the flat bottoms of there cars.. all wind tunnel work.. Even the New 599 GTB has those buttress just pass the back window that aid in downforce and air direction to the back end.