Analysis, Factors, and Reduction Techniques

CONTENTS
CONTENTS
:
:
1. INTRODUCTION
2. CLASSIFICATION
3. HISTORY OF CAR RACING
4. CAR DEVELOPMENT & RACING PHYSICS
5. IMPLEMENTATION OF AERODYNAMICS ON RACE CAR
6. DESCRIBE ON DOWNFORCE
7. EFFECTS OF FRONT,REAR WING & CHASSIS
8.ADVANTAGE
9. DISADVANTAGE
10. CONCLUSION

INTRODUCTION
Aerodynamics (shaping of objects that
affect the flow of air, liquid or gas) is a
branch of fluid dynamics .
Properties of the flow includes velocity,
pressure, density, and temperature, as a
function of space and time.
Understanding the flow pattern makes it
possible to calculate or approximate the
forces and moments

CLASSIFICATION OF
AERODYNAMICS PROBLEM
Classification of AERODYNAMICS ON FLOW:
External aerodynamics is the study of flow around solid
objects of various shapes.
Internal aerodynamics is the study of flow through
passages in solid objects
Characteristic flow speed to the speed of sound comprises
a second classification of aerodynamic into
Subsonic
Transonic
Supersonic
Hypersonic
The influence of viscosity in the flow dictates a third
classification

HISTORY OF CAR
RACING :
Aerodynamics has played a major role in
car racing since the late 1960s, when
introduction of the first inverted wings
appeared in some formulas
increasing cornering speeds and vehicle
stability
Introduction of ground effects
increase in downforce would provide more
grip to the track and hence more speed.
This idea was technically developed by
Chevrolet- Chaparral in 1966 with their
Can-Am racing car.

CAR DEVELOPMENT & RACING
CAR DEVELOPMENT & RACING
PHYSICS :
PHYSICS :
The aerodynamics of
the race car is multi-
functional.
The first purpose is
to make it as
streamline as
possible
second purpose is to
provide downforce
for the race vehicle.
The last reason is to
control the airflow
over the car’s body.

IMPLEMENTATION OF
AERODYNAMICS ON
RACING CAR
Automotive aerodynamics is the study
of the aerodynamics of road vehicles.
The main concerns of automotive
aerodynamics are reducing drag.
reducing wind noise.
and preventing undesired lift forces at
high speeds.
to produce desirable downwards
aerodynamic forces to improve traction
and thus cornering abilities.

BACKGROUND OF RACING CAR:
BACKGROUND OF RACING CAR:
DRAG:
Drag is the force that acts
opposite to the
path of the vehicle’s
motion.
Drag is detrimental
LIFT:
Lift is the force that acts
on a vehicle normal to the
road surface that the
vehicle rides on.

CAR DEVELOPMENT:
CAR DEVELOPMENT:
. Design and develop a race car that is safe, durable, and
competitive in different racing conditions.
Durability is required to complete the sixteen race
schedule. In addition, cars must meet the demands of four
different types of racing circuits, each course requiring a
different aerodynamic and mechanical setup.
1.STREET:
A narrow, temporary course ranging from 1.6 to
2.1 miles in length, with tight turns and a long
straightaway. The Long Beach circuit (lap record
108.198 mph), tests the durability of the gearbox,
braking system and low speed acceleration.
2.ROAD:
A road course is a wide open track that
ranges in length from 1.9 to 4 miles. It has
both slow and high speed corners and wide
enough for passing.

3.SHORT OVAL:
Phoenix International Raceway (lap record 172.804
mph), is a one mile, long oval track. Short
straightaway and banked turns are characteristics of
this type of track. The short oval tests the suspension
and aerodynamic setup of the car.
4.SPEEDWAY:
The speedway is an oval track with banked turns
and long straightaway. The one lap record at the
Michigan International Speedway (2 mile oval), is
234.275 mph. At Indianapolis (2.5 mile oval), the
record is 232.618 mph. High, sustained speed requires
aerodynamic efficiency.

DOWNWARD
DOWNWARD
FORCE :
FORCE :
Streamlining - to reduce high speed air resistance.
Generation of downforce by :
Reduction in wing or flap angle of attack.
Adding of inverted wings.
Attaching wing to unsprung suspension.
Shaping vehicles body –optimal choice
Implementation of former 3 lead to catastrophic.

The significance
of aerodynamic
downforce on
race car is to
improve the tire
adhesion.
This graph
shows that, when
slip angle is too
large, vehicle
slide.

TRENDS IN MAXIMUM
TRENDS IN MAXIMUM
CORNERING
CORNERING
ACCELERATION
ACCELERATION
Solid line shows the
general trend of
improving maximum
tire traction (similar
to friction coefficient)
over the years
The dashed line
shows the dramatic
increase that occurred
once the use of
aerodynamic
downforce began

FRONT WINGS
FRONT WINGS :
:
The front wing assembly is constructed of carbon fiber and is the first part of the
car to meet the air mass.
The flow field here is better than at other parts of the car because the air here has
been disturbed the least.
The wing is designed to produce down force and guide the air as it moves toward
the body and rear of the car.
Flaps and winglets may also be used to guide the air
past the wheels to the radiator inlets and underbody
The efficiency of the wing is based on the following:
1. Aspect ratio:
The length/width ratio is called the aspect ratio. The higher the
aspect ratio, the more efficient the wing.
2.Angle of attack:
The amount of down force generated is depend upon the angle
or tilt of the wing. The greater the angle of attack, the more down
force generated.
3.Drag :
Drag increases with the angle of attack. The down force
generated by the wing works in a vertical, downward direction,
while drag acts in the opposite direction to the airflow.

REAR WINGS :
REAR WINGS :
The rear wing is made of carbon fiber.
The airflow moves toward the rear of the car it becomes more turbulent.
The rear wing is not as aerodynamically efficient as the front wing, yet it
must generate more than twice as much down force to balance the car,
thus the rear wing assembly is designed to produce high down force.
The efficiency of the wing is based on:
1 Aspect ratio:
The higher the aspect ratio, the more efficient the wing.
2 Angle of attack:
. The greater the angle of attack, the more is the
down force and drag.
The angle of attack and the size of the rear wing will
vary from road, short oval and speedway setup.
3 Drag:
The down force generated by the wing works in a vertical,
downward direction, while drag acts in the opposite direction.

CHASSIS
CHASSIS :
:
The chassis is designed to produce
maximum downforce for the vehicle.
This is done in two ways:
Design of underbody
Giving a vehicle rake
so, the car can make sharp turns at
high speeds while maintaining
complete control of the handling.
A “rake” means the rear of the race
car is higher than the front. This
results in the car’s body acting as an
airfoil, and produces downforce for
the entire vehicle. The special design
of the underbody allows an area of
low pressure to produce under the
car. This results in the car being
sucked toward the track by the
passing airflow.

ADVANTAGE :
1 High speed.
2 Better aerodynamic grip.
3 Race car tire manufacturers desire to
maintain most of the side force under
moderate sliding conditions.
4 Commercial tire may have a negative
slope whereas the racing tire should
maintain a flat shape.
.

DISADVANTAGE :
1. Reduction in comfort& accessibility.
2. Reduction in fuel efficiency.
3. Road specific.
4 Design trend based on formula-1
regulation & current technology.
5 Costly

CONCLUSION :
The complexity of automobile and race car
aerodynamics is comparable to airplane aerodynamics
and is not limited to drag reduction only.
The generation of down force and its effect on lateral
stability has a major effect on race car performance,
particularly when high-speed turns are involved.
In the process of designing and refining current
race car shapes, all aerospace-type design tools are used.
flow separations, vortex flows, or boundary-layer
transition, the flow over most types
of race cars is not always easily predictable.
Due to the competitive nature of this sport
and the short design cycles, engineering decisions must
rely on combined information
from track, wind tunnel, and CFD tests.
LITERATURE

Analysis, Factors, and Reduction Techniques

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