초록 ▼

A low drag surface comprises at its upstream edge, an intermittent linear vortex producing means which extends transverse to the flow over the surface and produces a succession of rolling vortices extending transverse to said flow. The vortices move across the surface and reduce drag in the manner o

A low drag surface comprises at its upstream edge, an intermittent linear vortex producing means which extends transverse to the flow over the surface and produces a succession of rolling vortices extending transverse to said flow. The vortices move across the surface and reduce drag in the manner of roller bearings. In preferred embodiments the vortex producing means is mechanical, in the form of an oscillating part or fluid dynamic, in the form of a nozzle arrangement.

대표청구항 ▼

A low drag surface having a flow of fluid across it and comprising: an intermittent linear vortex producing means at its upstream edge extending transverse to the direction of said flow and producing a succession of rolling vortices extending transverse to said flow, said intermittent vortex produci

A low drag surface having a flow of fluid across it and comprising: an intermittent linear vortex producing means at its upstream edge extending transverse to the direction of said flow and producing a succession of rolling vortices extending transverse to said flow, said intermittent vortex producing means comprises a portion of said surface movable with respect to the remainder of said surface to produce a discontinuity which produces said vortex, said movable surface having two states, one in which it produces the vortex and the other in which it frees the vortex to move with the flow of fluid.