An airfoil of a propulsion device having a first riblet laminate with a first adhesive layer on at least a first portion of the airfoil surface and a first riblet array sheet disposed on at least a portion of the first adhesive layer. The first riblet array sheet defines a first plurality of contiguous geometric features having rigid peaks and valleys extending in a first rib direction. The first plurality of contiguous geometric features define a total width to total height ratio W:H of about 1:1 to about 2.5:1 with a maximum total height of about 0.65 mm or less. A second riblet array laminate is also disclosed in an embodiment.