Aerodynamic Analysis of External Flow for Hybrid Electric Vehicle (HEV)

The group goals and objectives are to design and construct a new design of aerodynamic
interchangeable body and new vehicle architecture. The objective of the project at this
stage is more on how to design vehicle shapes that produce desirable flow characteristic.
Nevertheless, the pursuit of drag reduction remains one of the principal objectives.
Theoretically, the shape of a moving vehicle causes the airflow to create force acting on
the surface of the vehicle. The force is known as drag force. Therefore, by streamlining
the vehicle body will help to reduce the effect of this force and increase its performance.
Besides, the vehicle will have an attractive body design and minimized its fuel
consumption.
The frontal area of a vehicle does influence the drag force exerted on the vehicle's body.
The drag coefficient (Cd) depends mainly on the shape of the vehicle, regardless of thensize
or driving speed. Therefore, there is a relation between frontal area and the Co, so
that the vehicle with low Cd and A will experience much lower aerodynamic drag, and
vice versa.
For this project, the important phases involve are the concept sketching, drawing and
simulation analysis. The concept sketching is about the ideas that are being looked for,
not refined designs. The selected concept was draw as a 3D drawing, using CATIA
software. Finally, the drawingwas used in computational fluid dynamics (CFD), using
the STAR-CD software. STAR-CD is a powerful CFD tool and it has a built-in links
with CAD/CAE systems. Several designs used in the CFD analysis and the result shows
the pressure distribution, separation points as well as the wake generated at the rear of
the vehicle. Various analysis and improvement of the design have been done, and as a
result die value ofCd which is 0.14, has been obtained.
As a conclusion, the combination of underbody profiling, front, and rear end would lead
to produce a vehicle shapes that produce desirable flow characteristic as wellas possess
low drag coefficient value.