| 摘要 |
The aerofoil comprises first and second surfaces 2, 4, the second being smooth at least part of the first comprising an undulating profile that may be produced by indentations 6 (which may be semi-spherical or tear drop shaped) or protrusions or a combination of the two. The aerofoil may comprise a wing, or the blade of a turbine or of a helicopter or may be used in toys. |
