摘要 |
Measures are disclosed for modifying the boundary layer flow over fluid dynamic surfaces using patterns of riblets having heights which are varied in the direction of the stream to compensate for the self limiting effect of the riblets in the action on the fluid, for the displacement of boundary layer turbulence due to progressive increase of the riblet heights, for effects dependent upon Reynolds Number and for variation of skin friction in the flow direction. In another aspect, riblet patterns are provided which modify the boundary layer flow through laminar, transitional and turbulent boundary layer regions. |