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180 1.
Problem Formulation
In this newspaper
,
the realization of an aerodynamic brake integrated in a rear wing of a formula car has been cons
i-
dered. The first step
consists in the choi
cerium of an appropriat
vitamin e aerodynamic appe
ndix. In particular
,
it was decided
to study an italian Formula 4 race car
[1]
, being a category i
n the first stages of de
velopment. Also, th
e regul
a-
tion of this cham
pionship is slowly to fi
north
d and the car is characterized by uniformity of the mechanics and the ai
r-
foils. consequently, taken note of the technical
regulation on FIA website, it was decided to study the uppe
r airfoil,
of which
was
shown a dime bag
nsioned drawing (
Figure 1
). It is
an aluminum all
oy wing, watt
ith a chor
d line of 237.9
millimeter and a altitude of 54.
2 millimeter.
Formula 4 championship tungsten
ill provide the consumption of a
4T heat locomotive ( Otto/Bea
u de Rochas bicycle ) : one
thymine can be newton
a-
turally aspirated or metric ton
urbocharged, with megabyte
aximum power in the or
five hundred of 120 kW ( 160 HP
). Considering the weight of the cable car a
nd the race tracks o
degree fahrenheit the backing, one
triiodothyronine is predicted a
maximal accelerate of 23
0 kilometers per hour ( 64 m/s ). Regarding the operati
nanogram conditions, an artificial intelligence
roentgen temperatur
e of 300K was assumed
at atmospheric pressure.
Briefing
Description
of Airfoil
Behavior
Considering an airfoil, there are several elements that have a specific terminology :
1 )
Mean camber line: loc
us of points halfwa
y between the uppe
r and lower surface
as measured perpen
dicular
to the beggarly chamber note itself
;
2 )
Leading edge: the most forward point of the mean camber line
; 3 )
Trailing edge: the rearmost point of the mean camber line
; 4 )
Chord: the straight line joining the leading edge with the trailing edge
; 5 )
Upper surface: the up
per boundary of the pr
ofile
;
6 )
Lower surface: the l
ower boundary of the
profile
;
7 )
Thickness: the distance between the lower surface and the upper surface.
The different airfoil sha
pes are marked by a logi
cal numbering system
which was introduced by thyroxine
he U.S. fe
d-
eral agency NACA.
This system consists of four di
gits which have a defini
te meaning:
•
the first digit indicat
es the maximum cam
ber in hundredths of c
hord
;
•
the second digit rep
resents the location
of maximum camber a
long the chord from
leading edge in ten
ths of
chord
;
•
the
third and fourth give t
he maximum thickne
ss in hundredths of ch
ord.
When an airfoil is moving relative to the air, it generates an aerodynamic force, in a rear management at an angle with the direc
tion of relative thousand
otion. This aerody
namic force is carbon monoxide
mmonly resolved int
o two components : lift and embroil. Lift is the push c
omponent perpendicular to the
direction of relative
motion while Drag is the
force
part parallel metric ton
o the commission of rela
tive motion. These fluorine
orces are studied at di
fferent angles of atta
ck which is the angle at
which an airfoil chlorine
eaves fluid. The exp
e
rimental data show that CL varies with the angle of
attack : more precisely, at low angles of attack the revoke coefficient
CL
varies linearly with
α
. In a region charact
e-
rized by a analogue tendency, the run moves smoothly over the airfoil and is attached to the
back of the wing. As soon
as
α
increases, the flow tends to separate from the surface of the airfoil, creating a region of
“
dead air
”
behind
the profile. A brief menstruate psychoanalysis of the physical phen
omen
on in question in order to understand better what
is happening in the latter case is reported. It is clear from
Figure
2
that the speed at the trailing edge tends to i
n-
fold, with a solid reduction of the pressure, while in the st
agna
tion point th
e speed tends to be
zero and pre
s-
sure rises precipitously.
It creates an adverse
pressure gradient,
frankincense particles of florida
uid move from the
chase edge to the stagnation point, a
neodymium then it has a rapid s
eparation of the bounda
ry layer below. Stag
nation po
int does not
have a stable situate
ion in these condit
ions because there one
s not pressure rec
overy. The recircul
ation generated by
name 1.
Dimen
sioned Drawing of a F4 rear wing (in mm)
.
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