AERODYNAMICS IN CARS

INTRODUCTION
• Aerodynamics is the study of how air moves around objects, particularly as it
relates to the forces and effects of air on those objects. It is a branch of fluid
dynamics and is essential in understanding the behavior of aircraft,
automobiles, buildings, and other objects as they interact with the air.
ADVANTAGES OF AERODYNAMICS IN CARS

• More stability of cars at higher speed

• More fuel efficiency
• Reduces noise pollution
• Higher speed of car
 FIELD OF APPLICATION
• Aerospace Engineering
• Design Of Automobile
• Prediction of forces & moments in ships and sails
• In design of bridges and buildings for calculating wind loads
 Aerodynamic Forces
• Lift (causes body to rise)
• Drag (Fluid resistance)
• Weight
• Thrust
 STUDY OF AERODYNAMICS IN CAR
In order to improve the aerodynamics of cars, we must know how the flow
of air past a car. the major forces which affecting the motion of car in fluid
flow are,

1.Drag Force
2.Lift or Down force.
• Drag Force:- Some energy are lost to move the car through the air & this energy is used to overcome a
Drag force. In vehicle aerodynamics drag is due to Frontal pressure and Rear vacuum. For calculating
drag force following formula is use
F = ½ CDAV²
Where, F - Aerodynamic drag force A - Frontal area
C - Coefficient of drag
D-Density of air
V - Velocity of object
 FRONT END OF CAR
Drag Force due to Frontal pressure:-
o This Drag force is caused by the air attempting to flow around the front of the
car. When Air molecules approaches the front of the car they begin to compress
and raise the air pressure in front of car.
o Frontal pressure is reduced by minimizing exposed frontal surface area and
making front end smooth, continuous curve originating from the line of front
bumper allowing the air molecules to pass smoothly.
 REAR END OF CAR
Drag Force due to Rear Vacuum:-
• Rear vacuum is caused by the Flow Detachment in the air flow as the car
passes through it. Flow Detachment is inability of air molecules to fill the
empty zones which are created at the rear end of vehicle. Which results in
continuous vacuum zone in the opposite direction of Vehicle motion in the rear
area.
• Drag forces increases due to turbulence in the rear end which is caused due to
flow detachment
 Lift and Downforce
Lift : Lift is an aerodynamic force that acts perpendicular to the road surface and in
an upward direction. It is similar to the lift generated by an aircraft wing but in the
context of a car, it's an undesirable force

Cause: Lift occurs when the aerodynamic forces on the car's body create a pressure
difference that results in a net upward force. This can happen when the shape of the car's
body generates lift-inducing conditions, such as low-pressure zones on the upper surface of
the vehicle.

• Downforce: Downforce is an aerodynamic force that acts perpendicular to the road

surface and in a downward direction. It is a desirable force for high-performance and
racing cars.
Cause: Downforce is generated by the car's aerodynamic elements, such as wings, spoilers,
diffusers, and underbody designs. These elements manipulate the airflow around the car to
create higher pressure on the top and lower pressure on the bottom, resulting in a net
downward force.
 AERODYANAMICS DEVICES IN CARS
• WINGS

• SPOILERS

• SCOOPS
 METHODS FOR EVALUATING AERODYNAMCIS
OF CARS
Wind tunnel:-
• A wind tunnel is a research tool developed to study the effects of air moving
over or around solid objects.
• Air is blown or sucked through a duct equipped with a viewing port and
instruments where models or geometrical shapes are mounted for study.
• Wind tunnel testing is a trial and error process.
SOFTWARES:-
• Number of software's are developed for the analysis and optimization of
aerodynamics in automobiles.
• For the design and analyzing aerodynamics the most commonly used
software's are CATIA, HYPERMESH, ICEMCFD, FLUENT and other CFD
software.
• Software programs makes possible to test small size parts which are costly in
the wind tunnel.
 CONCLUSION
Aerodynamics plays a pivotal role in improving car
performance, efficiency, and safety. Constant
advancements in aerodynamic design techniques,
along with the application of innovative
technologies, will continue to shape the future of
automotive engineering.
THANKYOU

ARYAN GUPTA
201105008
MECHANICAL