commercial vehicle aerodynamics ............................................................................................................................................ .....................................................................................................................................................................................................

1. CASESTUDYOF
AERODYNAMICS
FEATURESOF
COMMERCIAL
VEHICLES
BY PATEL MEET KALPESHBHAI
190160102049
PATEL JAY JAGDISHBHAI
190160102046
SATHAVARA DEVANG SURESHBHAI
19160102059

2. INTRODUCTION
 Aerodynamic styling involves adapting the shape of a vehicle to reduce the
drag it creates as it moves through the air
 At present the aerodynamic design of heavy trucks is based largely upon wind
tunnel estimation of forces and moments, and upon qualitative streamline
visualization of flow fields.
 When a vehicle moves, the air exerts a force on the vehicle that resists its
motion. This force is the aerodynamic drag and it has a significant effect on the
fuel consumption of vehicles
 Aerodynamic drag is affected by vehicle shape, frontal area and speed.

3. THE EFFECT OF CAB TO TRAILER BODY HEIGHT
• In case of sharp upper windscreen leading edge with the
lower trailer body the air flow cannot follow the contour of
cab and thus overshoots both cab roof and trailer.
• With medium height trailer body the airflow again
overshoots but tends to align and attach to the body roof.
• With the high body the overshoot again occurs, some of the
air then hits the front of the trailer body but the vast majority
deflects off the trailer body before reattaching.

5. Common Aerodynamic Features

6. Basic Vehicle Feature
Basic features that influence the aerodynamics of a vehicle may be determined by vehicle
specification, and must be considered when acquiring new or used vehicles.
• Cab/Container Gap Minimisation
Minimising the gap between the cab and trailer on articulated/drawbar vehicles is a simple way
to improve aerodynamic performance. This causes a change in pressure, increasing the total
drag of the vehicle.
• Cab Front Edge Rounding
Vehicle drag can be reduced by rounding the front edge of the cab. The reduction you achieve
will depend on the shape of the vehicle.
• Cab/Container Height Equalisation
A closer match between cab and container heights will reduce the drag. Heights can be
equalised by using deflectors or fairings, or by changing the body.

7.  Truck Cab Features
• Cab Roof Deflector
Fitted to a cab roof, this flat or contoured plate can be set at different angles to suit the
body and is probably the most effective single add-on for vehicles using bodies of varying
heights.
• Cab Roof Fairing
Roof fairings are three-dimensional mouldings which fit on the cab roof and, if adjustable,
can allow maximum savings with a range of differing body heights.
• Cab Collar and Roof Fairing
This is either a fixed piece mounted on the front of the body or a rearward extension to a
specific fixed roof fairing, available as new or retrofit.

8. • Cab Side-edge Turning Vanes
Usually located on the cab front edges below the windscreen level, these small
extension pieces can reduce drag if they cover sharp edges and also help to reduce the
build-up of road film and dirt.
• Air Dam
Most modern vehicles come fitted with air dams, but they can also be retrofitted.
Instead of allowing air to pass through the rough under-body, air dams divert air around
the sides of the truck, thereby reducing the contribution of the vehicle under-body to the
drag.
• Cab Side-edge Fairings
Cab side-edge fairings bridge the gap between the cab and body so are effective in
reducing drag. Located at the sides of the rear cab edges, these fairings are available
as new or retrofit.

9.  Body Features
• Gap Seals or Vortex Stabilisers/Generators
A gap seal or vortex stabiliser/generator has the most impact on trucks with a large gap
between cab and body. A gap seal is mounted on the front face of the body, extending
forwards almost to the cab and vertically from the base of the body to the height of the
cab.
• Container/Trailer Roof Tapering
Drag caused by the rear of a vehicle can be reduced by tapering the rear of the container
or trailer.
• Trailer Roof Height Reduction
Drag can be reduced if the trailer height on articulated vehicles is lower than the tractor.
However, the fuel efficiency benefit must be weighed against any loss in revenue resulting
from having a smaller load space.

10. • Container Front Fairing
Container front fairings are mouldings around the edge of the front of the body or drawbar
trailer.
The fairings encourage the airflow to stay attached at the front of the body roof and sides,
thus reducing drag.
• Aerodynamic Sloping Front Roof Trailer
The aerodynamic sloping front roof trailer has been designed to improve the aerodynamic
profile of articulated vehicles. The maximum potential internal load height is usually around
3.3 m,

11. References
• https://www.sae.org/publications/technical-papers/content/2011-01-2284/
• http://aerodyneuk.com/fuel-saving/truck-aerodynamics/
• https://www.volvotrucks.com/en-en/news-stories/magazine-online/2022/apr/new-
aerodynamic-improvements-to-the-volvo-fh.html
• https://link.springer.com/chapter/10.1007/978-3-319-20122-1_12
• http://aerodyneuk.com/truck-aerodynamics/

12. THANK YOU