Smoke-wire flow visualization showed that the presence of the MRF on the airfoil surface caused the smoke filaments to become thinner and to be separated by a smaller lateral spacing, indicating suppression of spanwise movement. At the downstream end of vortex formation region, the Reynolds shear stress and turbulent kinetic energy for the MRF-covered airfoil were similar or slightly larger than for the smooth airfoil. For the case of drag reduction (Re=1.54×10 4 ), the near wake behind the MRF-covered airfoil had a shorter vortex formation region and higher vertical velocity component compared with that behind the smooth airfoil. To determine the spatial distributions of turbulence intensity, including the mean velocity, turbulence intensity and turbulent kinetic energy, 500 instantaneous velocity fields of the wake behind each airfoil were measured using a 2-frame PIV technique and ensemble averaged. In contrast, at the higher Reynolds number of Re=4.62×10 4 ( U 0=9 m/s), application of the MRF increased the drag force by about 9.8%. At Re=1.54×10 4 ( U 0=3 m/s), the drag force on the MRF-covered airfoil was about 6.6% lower than that on the smooth airfoil. The drag force acting on each airfoil, as well as the spatial distributions of turbulence statistics in the near wake behind each airfoil, were measured for Reynolds numbers (calculated based on the chord length, C = 75 mm) ranging from Re=1.03×10 4 to 5.14×10 4. The results were compared with the corresponding results from an identical airfoil covered with a smooth polydimethylsiloxane (PDMS) film of the same thickness. The flow structure of the wake behind a NACA 0012 airfoil covered with a V-shaped micro-riblet film (hereafter, MRF) has been investigated experimentally.