Physics behind spoilers/wings

[EclipseBabe95]

hey, i had a quick question. i've done some searching, and couldnt find anything on the actual physics/aerodynamics about wings/spoilers.

from what i understand, spoilers disrupt airflow over the top of the car, preventing the body of the car from acting like an airfoil and generating lift.

and i know wings generate downforce, but how exactly do they do it? i mean, on dragsters they have massively angled wings for downforce on the rear tires.... which makes sense.... but on fwd cars, that would be pointless.......

so my only other hypothesis would be that on normal street cars like a gst, the wing actually generates lift, and since its behind the rear wheels, the rear axle acts as a sort of fulcrum which then puts more downforce on the front end....

just wondering if anybody could explain to me whether my guesses are right, or whether im completely retarded and off-base. thanks.

[thecackster]

Accually... most wings are just for looks ... they really don't come into affect into about like 120's range, (any one that knows for sure feel free to add). But like an airplane wing creates lift causing the air over the top to move more rapidly, spoilers create downforce using the same method but reversed, i assume. I'm no physics major but....i gave it my best. AS for your front wheel creating lift theory... not so sure thats what happens... pretty much useless IMO.

[drdisque]

all wings on street cars are either for looks or to prevent the rear end from lifting up and getting dicey on the freeway (TT, Beetle Turbo, Crossfire)

[real_madridcf]

Just a little something to read up on!

http://www.answerbag.com/q_view.php/3725

" Rear wings and spoilers were invented to address these lift and
airflow issues. Wings come in many shapes and sizes, but they
share a common characteristic---a narrow, horizontal surface,
mounted away from the body in clean, undisturbed air. (Wings
mounted close to the body are either nonfunctional or act more like
spoilers, described below.) Wings add downforce---the opposite
of lift. One way to create downforce is to shape the wing into an
airfoil---an airplane wing of sorts---and turn it upside down. This
forces the flow below the wing to travel at a higher velocity then the
air above, creating a downward force. A second way to create
such downforce is to angle the front of the wing slightly downward
into the airflow. This creates more drag then a horizontal airfoil,
but it can allow adjustability of the downforce.

To differentiate a spoiler from a wing, thik of turkey plumage.
The spoiler is an angular, liplike appendage attached to, or
designed into, the rear of the car. It can be used to create downforce
like a wing , but it's more commonly used to reduce lift or drag. On
hatchbacks, a lip spoiler can create a pool of air ahead of the
spoiler that separates the airflow from the backlight, reducing lift.
It can also be used at the rear of the car to launch the airflow cleanly
away from the vehicle, preventing its tendency to remain attached to
the car's trailing surfaces. This can decrease drag as well as reduce
the underbody pressure that contributes to lift.

Automakers were hard at work on drag reduction as far back as the
1930s. It wasn't until the early 1960s, as both race-car and
production-car top speeds approached 200 mph, that lift became an
issue. Ferrari racer Richie Ginther is credited with inventing the
rear spoiler for downforce in 1961, and discreet rear spoilers started
appearing on competition Ferraris soon thereafter. One of the first
cars to use a front air dam was Ford's GT40. The high snouts of
early prototypes produced so much lift at 200 mph that they were
virtually undrivable. Fitting a air dam increased the force on the
front-tire contact patches from 310 pounds to 604 pounds at top
speed. The Dodge Charger Daytona and Plymouth Superbird
twins of 1969-70 were among the first production cars to sport
a rear wing. The adjustable wing, supported high above the rear
deck by finlike butresses, combined with changes to the nose of the
car (including an air dam) to increase downforce at both ends
of the car. "

[JoeWagon]

You put way too much thought into it. Why it works is one thing, stick your hand out the window on the highway pointed down. The air pushes your hand down, downforce on cars with spoilers.

It's pretty easy to see why people want wings on their car, they want to be more like a fast car that actually uses it.

There's no 'fulcrum' involved on a FWD car, they don't generate downforce because they aren't functional.

[thecackster]

Hey what what I said, but made much more sense ....so much more simple...but thats the basic Idea.