| 摘要 |
An aerodynamic unit 22 attachable onto a roof 12 of a road vehicle or trailer, so that air passes over the unit 22 during forward movement of the road vehicle. The unit 22 has a first, or leading end (28) positioned distal to a rear end 24 of the vehicle roof 12, and a second, or trailing end 24 positioned proximal the rear end 24 of the vehicle roof 12. The unit 22 includes an inclined guide portion 29 which decreases in height in a direction towards the trailing end 24 of the unit 22 and a flow director 38 at or near the leading end 28 of the unit 22, for directing air flow to the guide portion 29. The flow director 38 is configured to have a height increasing in a direction from the leading end 28 towards the trailing end 24. The unit 22 may include vortex generators 32 protruding from the guide portion 29. A fin 40 may extend along each side of the unit 22 in a direction between the trailing end 24 and the leading end 28. |
