Velocity Measurement About a NACA 0012 Airfoil with a Laser Velocimeter,

A laser velocimeter measured the velocity field about a wing with a NACA 0012 airfoil section. These measurements were compared at two low angles of attack 0 deg, 4.15 deg with a two-dimensional viscous-flow prediction program. At 0 deg, the comparison provided confidence in the effectiveness and accuracy of the laser velocimeter. At 4.15 deg, the data indicated that a small laminar separation bubble with oscillating shear layer probably existed. The unique capability of the laser velocimeter in measuring absolute flow magnitude and direction without prior knowledge of general flow direction was demonstrated in the complex separated reverse flows over the wing at an angle of attack of 19.4 deg.