Abstract: An active drag-reduction system has first 22 and second 24 fluid outlets located on a vehicle 10 adjacent to a low pressure (drag) region 12, wherein fluid ejected from the second fluid outlet 24 is at a higher pressure/ejection velocity than from the first fluid outlet 22. Turbulent and/or low pressure regions adjacent to vehicles are not uniform, but rather have a varying intensity. For instance, the centre of a region may have a lower pressure and/or more turbulent nature than the periphery of the region. The system injects relatively higher pressure air or relatively higher speed air into the relatively lower pressure/more turbulent part of the low pressure/turbulent region, and relatively lower pressure air or relatively lower speed air into the relatively higher pressure/less turbulent part of the low pressure/turbulent region, compared to each other.

Abstract: There is provided an active drag-reduction system having first 22 and second 24 fluid outlets located on a vehicle 10 adjacent to a low pressure (drag) region 12, wherein fluid ejected from the second fluid outlet 24 is at a higher pressure/ejection velocity than from the first fluid outlet 22. Turbulent and/or low pressure regions adjacent to vehicles are not uniform, but rather have a varying intensity. For instance, the centre of a region may have a lower pressure and/or more turbulent nature than the periphery of the region. The system may inject relatively higher pressure air (or relatively higher speed air) into the relatively lower pressure/more turbulent part of the low pressure/turbulent region, and relatively lower pressure air (or relatively lower speed air) into the relatively higher pressure/less turbulent part of the low pressure/turbulent region, compared to each other.