This document discusses vehicle aerodynamics and the importance of aerodynamic shape. It covers the forces acting on an automotive body, including lift, drag, thrust, and weight. Design considerations for aerodynamic shape are outlined, such as keeping the vehicle low to the ground and avoiding sharp angles. Maintaining the aerodynamic shape can improve fuel efficiency and reduce skin friction. The benefits of aerodynamic design include increased efficiency, performance, stability, and improved appearance.

1. Shree S’ad Vidya Mandal Institute
of Technology
Prepared By:- Urvesh D Prajapati
Enrolment No.:- 140453119029
Department:- Mechanical
Semester and Division:- 8th C3
Guided By:- Asso. Prof. D. C. Gosai
Topic Name:-

2. CONTENT
1. Introduction about Vehicle Aerodynamic.
2. Significance of Aerodynamic Shape.
3. Forces on Automotive Body.
4. Design Consideration of Aerodynamic Shape.
5. Maintain Aerodynamic Shape in Cars.
6. Benefit of Aerodynamic Shape.

3. 1. Introduction about Vehicle Aerodynamic
• When objects move through air, forces are generated by the relative motion
between air and surfaces of the body, study of these forces generated by air is
called aerodynamics.
• The power delivered by the engine is finally made available at the drive wheel as
propulsive or tractive force.
• This propulsive or tractive effort, available at contact between driving wheel and
road should be more than the total resistance for motion of a vehicle.
• The surplus tractive effort contribute for acceleration, climbing gradient etc.

4.  Vintage Car without Aerodynamic
Shape
 Today’s Car with Aerodynamic
Shape

5. 2. Significance of Aerodynamics Shape
• Reduction of drag force and achieve maximum speed and acceleration for the
same power output.
• Reduction of drag force improves fuel economy.
• Good aerodynamic design gives better appearance and styling.
• Good stability and safety.
• Good aerodynamic design provide proper ventilation, reduce noise.

6. 3. Forces on Automotive Body
Following are the forces acting on
automotive body as shown in figure.
Lift,
Drag,
Thrust,
Weight.

7. • Lift:- It is the vertical component of resultant force caused by pressure
distribution on vehicle body.
F = ½CLV²Aρ
Where, CL = Co-efficient of lift,
V = Velocity of body,
A = Frontal area of body,
ρ = Density of Air
• Drag:- It is the sum of all the dynamic forces in the direction of fluid flow, so it
acts opposite to the direction of body.
F = ½CDV²Aρ
Forces on Automotive Body (Cont.)

8. • Thrust:- Force produced in the opposite direction to drag that is higher than
drag so the body can move through the air or fluid.
• Weight:- Its just the weight of the object in motion. It affects the acceleration of
the object.
Forces on Automotive Body (Cont.)

9. 4. Design Consideration of Aerodynamic shape
Following are the point to be consider while designing aerodynamic shape,
• Keep the vehicle low to ground.
• Avoid open areas.
• Make corners round instead of sharp.
• The body should be as smooth and continuous as possible.
• Their should be no sharp angles.
• All body panels should have a minimal gap.
• Make use of spoilers.

10.  Aerodynamic Shape in Car

11. 5. Maintain of Aerodynamic Shape in Cars
Following are the main point to maintain aerodynamic shape in cars,
• Keep your vehicle washed and waxed (reduces skin friction).
• Remove mud flaps from behind the wheels.
• Add a spoiler to the rear of the car.
• Drive in closed sun roof and windows.

12. 6. Benefit of Aerodynamic shape
Following are the benefits of Aerodynamic shape,
• More efficiency.
• More speed (increased performance).
• More stability (even at higher speeds).
• Good looking (design improvements).