A low drag surface is provided for a fluid washed object, the low drag surface comprising an aerodynamic surface comprising a cut-out region, and a continuously translatable surface comprising a surface portion. The surface portion is positioned in the cut-out region such that the aerodynamic surface and the surface portion form a fluidwash surface, and the surface portion is translatable relative to the aerodynamic surface.

A low drag surface is provided for a fluid washed object, the low drag surface comprising an aerodynamic surface comprising a cut-out region, and a continuously translatable surface comprising a surface portion. The surface portion is positioned in the cut-out region such that the aerodynamic surface and the surface portion form a fluidwash surface, and the surface portion is translatable relative to the aerodynamic surface.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

A system includes an elongated cylindrical body having a first end extending to a second end; an outer surface and an inner surface; a thickness extending from the inner surface to the outer surface; and a plurality of openings extending from the inner surface to the outer surface. The system further includes a fluid injection apparatus disposed within the elongated cylindrical body, the fluid injection apparatus is configured to pass fluid through the openings.

A system includes an elongated cylindrical body having a first end extending to a second end; an outer surface and an inner surface; a thickness extending from the inner surface to the outer surface; and a plurality of openings extending from the inner surface to the outer surface. The system further includes a fluid injection apparatus disposed within the elongated cylindrical body, the fluid injection apparatus is configured to pass fluid through the openings.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

A method and apparatus are presented. An active flow control system comprises a flow control valve, a manifold, and a temperature control system. The flow control valve is configured to control a flow of air into the manifold. The manifold is operatively connected to a number of actuators. The temperature control system is configured to heat at least a portion of the flow of air.

A switching unit may be provided for connecting a first pneumatic unit and a second pneumatic unit of a pneumatic system together. The switching unit comprises a main body having: a channel structure which extends through the main body; a first and a second inlet for introducing a pressure into the channel structure; a first and a second outlet for discharging at least some of the pressure from the channel structure; and a first and a second valve; wherein the first inlet can be brought into a pressure-exchange connection to the first outlet via a first channel by setting a first switch position of the first valve or to the second outlet via a second channel by setting a second switch position of the first valve, and wherein the second inlet can be brought into a pressure-exchange connection to the first outlet via a third channel by setting a first switch position of the second valve or to the second outlet via a fourth channel by setting a second switch position of the second valve.

A structure adapted to traverse a fluid environment includes an elongate body having a root, a wingtip, a leading edge and a trailing edge; and a plurality of rigid projections each extending from a respective position along the leading edge and/or the trailing edge generally along the same plane as a front surface of the body.

A structure adapted to traverse a fluid environment includes an elongate body having a root, a wingtip, a leading edge and a trailing edge; and a plurality of rigid projections each extending from a respective position along the leading edge and/or the trailing edge generally along the same plane as a front surface of the body.