Apparatus for producing a force when in a moving fluid

A device which is to be placed in a fluid moving in a first direction in order to produce a force in a second direction which is substantially transverse with respect to the first direction, wherein said device comprises an elongated body having in cross-section a rounded and symmetrical profile with respect to an axis of symmetry which defines with the first direction an angle of incidence, said profile defining a rounded and elongated leading portion whose thickness increases from the front to the rear and a rounded trailing portion whose thickness decreases from the front to the rear, the maximum thickness of the profile being between 50 and 100% of its length in the direction defined by its axis of symmetry, said elongated body comprising an impermeable envelope having two permeable suction areas which are symmetrical with respect to said axis of symmetry and located at least on the trailing portion of the profile, and a circular arc-shaped, impermeable envelope portion, which is orientable in order to cover one of said suction areas located on a side of the profile opposite to the side on which said force is to be produced, said device further comprising means for sucking the fluid into the body through the other of said suction areas, and a single substantially planar, rigid flap, which projects radially with respect to the body, said flap being carried by said impermeable envelope portion in order to form an assembly with the latter, and said flap being located on the trailing portion of the profile, on said side of the profile opposite to the side on which said force is to be produced, whereby the direction of said force can be changed by displacing said assembly from one side of the profile to the other.

A device adapted to be placed in a fluid moving in a first direction for producing a force in a second (force) direction substantially transverse to said first direction, comprising

• an elongated body having in cross section a rounded profile symmetrical with respect to an axis of symmetry and having a leading portion increasing in width along said axis of symmetry from the tip of said leading portion to a maximum width and having a trailing portion decreasing in width along said axis from said maximum width to the end of said trailing portion,
• means located symmetrically on both sides of said axis of symmetry and at the trailing portion of said profile for controlling the boundary layer of said fluid over the surface of said body to cause said fluid to flow smoothly over said body surface,
• a flap extending outwardly from said body and adjustable over said profile trailing portion to positions on either side of said axis of symmetry, and
• means for rendering said boundary layer control means ineffectual on one side of said axis of symmetry and for adjusting said flap to a position at said one side.

A device adapted to be placed in a fluid moving in a first (fluid) direction for producing a force in a second (force) direction substantially transverse to said first direction comprising

• an elongated body having in cross-section a rounded profile symmetrical with respect to an axis of symmetry,
• said profile having a leading portion increasing in width along said axis of symmetry from the tip of said leading portion to a maximum width and having a trailing portion decreasing in width along said axis from said maximum width to the end of said trailing portion,
• said leading portion being elongated and longer than said trailing portion in the direction of said axis of symmetry,
• and a flap extending outwardly from said body along said trailing portion on one side of said axis of symmetry.