Active and passive boundary layer control for vehicle drag reduction

摘要

An active and passive boundary layer control system and method for reducing boundary layer separation and the resulting form drag from ground vehicles. Tubings with multiple venturis connected in series are attached to the side and/or roof of the ground vehicle. A flow of compressed air is created by an engine auxiliary, e.g., a turbocharger or a supercharger, or by a designated blower and injected into the tubings. Suction created by the venturis actively removes decelerated fluid from the boundary layer and keeps the boundary layer flow attached. Optionally, the system exhausts the air in concentrated free jets along the vehicle body to a series of passive boundary layer control devices, such as vortex generators.

主权项

1. A device for reducing aerodynamic drag of a ground vehicle, the device comprising:
a tubing having an intake port, an exit port, and a plurality of venturis; and, a compressed air source being fluidly connected to the intake port; wherein the plurality of venturis is disposed between the intake port and the exit port; wherein each venturi from among the plurality of venturis has a throat and a venturi opening on an outer periphery of the venturi to remove a portion of a fluid from a boundary layer of the ground vehicle; and, wherein a venturi from among the plurality of venturis being disposed closer to the intake port has at least one of a larger throat cross-section and a larger venturi opening diameter than a venturi being disposed closer to the exit port.