Patent ID: 8899660

Claim:
In combination with a land vehicle having a body disposed above wheel assemblies and being configured to move relative to a surrounding air in a generally horizontal plane parallel to a surface of the land and being subject to an air drag, side forces and side moments due to a relative velocity between the vehicle and the air, a system to be mounted underneath the vehicle body and configured to reduce the air drag, the side forces and the side moments as the land vehicle moves relative to the surrounding air, the system comprising: at least one aerodynamic skirt disposed under said body of the vehicle, said skirt comprising: an assembly of airflow-controlling elements arranged to form a surface of said skirt, said airflow-controlling elements obstructing a part of an area of said surface; said assembly having unobstructed openings occupying a part of said area which is not obstructed by said airflow-controlling elements; and said assembly being disposed and configured to control adaptively an injection of the surrounding air under the body of the vehicle in accordance with the relative velocity between the vehicle and the air and to reduce the air drag, the side forces and the side moments acting on the vehicle; wherein at least one of said airflow-controlling elements having unobstructed gaps in its surface; and said unobstructed gaps being disposed and configured to inject small-scale vortices and air jets under the body of the vehicle and intensify small-scale turbulent mixing under the body to reduce further the air drag, the side forces and the side moments acting on the vehicle.