The outer skin (100) of an aerodynamic body (40) has perforations (200)
arranged in particular patterns in respective spanwise extending groups
or bundles (250). Each perforation is preferably a micro-slot with a
length of 100 to 3000 .mu.m and a width of 50 to 250 .mu.m. Air is sucked
through the micro-slots from the boundary layer flowing over the outer
skin, to achieve boundary layer control. In each bundle, the pattern,
size, orientation, and other parameters of the micro-slots are designed
to achieve mutual destructive interference of flow disturbances arising
due to the suction, to minimize the excitation of flow instabilities in
the boundary layer. Particularly, the spatial spectrum of the perforation
pattern of a given bundle is essentially absent of significant energy at
predetermined wavelengths of predetermined flow instabilities that
otherwise appear in the boundary layer air flow. The aerodynamic body
further includes supporting ribs (300) extending parallel to the
perforation bundles (250) and a perforated inner plate (400) providing a
throttling control of the suction flow through groups of the bundles.